DAHSYAT!!!, BARU GABUNG DAPAT RATUSAN RIBU- JUTAAN RUPIAH SETIAP HARI
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English question

68. If he prepared the test, he……his test.
a. passed
b. Would be passed
c. Would have passed
d. Would pass
e. Had passed

69. I Would have gone to Bali if I had got the money. The statement means…..
a. I didn’t go to Bali although I got the money
b. I went to Bali although I didn’t get the money
c. I didn’t go to Bali, because I didn’t get the money
d. I went to Bali, because I got the money
e. I went to Bali because I didn’t get the money


70. Mother : Have you cleaned the kitchen ?
Ira : …..mum.I forgot.
a. Thank you
b. Don’t worry
c. To forgive
d. Forgiveness
e. Forgive me

71. Ridho : Please….me for losing your book.
a. Forgive
b. Forgiving
c. To forgive
d. Forgiveness
e. Forgives

72. They will go swimming if……….
a. It doesn’t rain d. Isn’t rain
b. It rained e. It will not rain
c. Didn’t rain

73. Retno : I’m sorry I couldn’t come for your house last night?
Vivi : What happened ?
Retno : ………
a. I have a visitor
b. I got a visitor
c. I had been a visitor
d. I will have a visitor
e. I would have a visitor
This text for number 74 –7 8.

Telecommunication

The greek word tele means far off. Tele-comunication refers to long distance communi-cation radio, telegram, telephone, and television.

Telecomunication system is very fast because the sound and the picture signals travel as electric current along wires, radio through the air and space, or light waves along glass fiber. Radio waves and signals travel almost as fast. Telephone and Radio networks us communication satellites orbiting in space high above the earth.

Telecomunication system is any set of device and technique employed for the long distance transmission of voice, data, teleprinter, or television signals.All communication system operate according to the same being principles. They differ from each other chiefly in the specific types for information handled and the media over which they are transmitted. Familiar examples of such system are radio, televisin, telephone, telegram, and computer based data exchange or retrieval system are radio telecimunication system information via view, radio, or space satellite.

74. Which statement is not true according to the text ?
a. Telephone net works are exchanging data
b. Telephone meets you with someone far way
c. Radio networks transmit sounds and pictures
d. Communication anable us to make worldwide telephone.
e. Communication is just signaling information.

75. What is the main idea of the second paragraph?
a. How the satellite orbits in a space
b. How the sound and picture travel.
c. How use of communication satellite.
d. How radio waves and signal travel.
e. The reasons why telecommunication is very fast.


76. Why is telecommunication very fast ?
a. Because the long distance communication is electric.
b. Because the information is transmitted to distant place
c. Because all the system are operated according to the same basic principle.
d. Because the sound and picture signals travel like electric current.
e. Because the communication satellites are orbiting in space high above the earth.

77. Which of the following equipments sends a message received from machines in other place ?
a. Radio
b. Telegram
c. Handphone
d. Television
e. Teleprintewr

78. “Telecomunication system is any set of device and technologies employed for the long distance transmission of voice….”
a. Installed d. Applied
b. Operated e. Made
c. Producted

79. You wouldn’t buy car because you…..rich.
a. Hadn’t been d. Weren’t
b. Are not e. Isn’t
c. Were

80. Siska…..if she….the contest last mont
a. Will go abroad – wins
b. Would go abroad – won
c. Would have abroad – win
d. Would have gone abroad – had won
e. Will go abroad – win

81. You would get a scholarship if you…diligent.
a. Was
b. Is
c. Were
d. Had been
e. Are

82. “….more could be learned in this way that in any other”.
a. To make accurate measurements.
b. To show the important of measurements
c. To learn to make accurate measurements
d. To way Galileo made accurate measurements
e. To important of making accutrate measure-ments


83. Husband : Our car always trouble me.
Wife : Why don’t you sell it and buy a new one ?
Husband : Well, I don’t any objection to your idea as long as we can efford it.
In the dialogue, the husband express….
a. Sympathy d. intolerance
b. Capability e. pleasure
c. Agreement

84. Student : Is man able to find an efficient way to concert the heat of the sun into energy?
Teacher : ….because a lot experiments have been done and the result is quite positive.
a. It’s quite improbable
b. It’s out of question
c. There’s always a chance
d. I don’t think it’s possible
e. There’s no certain of it.

85. Bobby : will you go to the movie with me last night?
Henny : I would love to but I don’t think I can.there is so much homework to do
From the dialogue, we know that Henny is…..
a. Stating agreement
b. Giving an opinion
c. Accepting an opinion
d. Asking for permission
e. Refusing the invitation



This text for number 86 – 87
Most people do not think of coffee as a drug, but in fact. It is a drug and it has important effect are good and some are not. Coffee can help you stay awake when you are driving or working. But, it went you are awake at night when you want to sleep. Coffee makes some people feel more alive so they can work better. Other feel too nervous when they drink coffee. After a large meal, coffee can help your stomach. But, to much coffee can cause a stomachache.

86. The topic of the above paragraph is……
a. Coffee as a drug
b. The important of coffee
c. A disease cause by coffee
d. The reason why people drink coffee
e. Some effects coffee on our body

87. One of the reason people drink coffee is to…..
a. Reduce pain
b. Relieve stomachache
c. Make them stay awake
d. Make them feel stronger
e. Help them sleep soundly

88. Student A :Have you visited Mulawarman Palace? It’s the oldest palace in Kalimantan.
Student B : No, I haven’t but I hope to be able to do it next time.
The underlined expression shows……..
a. Refusal
b. Agreement
c. Invitation
d. Expection
e. ecception

89. Coah :What kind of sports do you play work?
Ilyas :….and I was the runner up in the last school competition.
a. I am good at tennis
b. I don’t know anything about it
c. I am not capable of doing any sports
d. I don’t think I have the ability to run
e. I don’t like any kind of sports
This text for number 90– 91

Memorandum
To :Ramadani,Ir. Engineering Departement
From : Director
Date : July 7, 2003
Subject : Elena Kozikov Ukranian Engineer
Dr,Elena Kuzikov will be visitor our company on Tuesday, September 7th. I would like you to prepare a program for her. She will arrive in the morning before noon. Please start with lunch and then show your


90. What is the purpose of this memo?
a. To prewpare a program
b. To show the department
c. To give recommended
d. To tell the true
e. To have lunch

91. When was the memo written ?
a. September 1st 2003
b. July 7th 2003
c. July 20th 2003
d. September 30th 2003
e. September 4th 2003

92. Chairil Anwar is regarded as a poiner in a modern Indonesia…..
a. Erticle d.verves
b. Poet e. prose
c. Poetry

This text for number 93 - 94
The Office Writer’s Handbook
Is a necessary work for anyone who has to write for business purpose. It states the relus of English grammar accurately and clearly, and show you to aply them to you writing. It also gives approved formats for business letters, report, and even charts. A special section covers the most common writing mistakes and how to avoid them.

93. What material is covered in the special section?
a. Sample charts
b. Writing formats
c. Sample business letters
d. Common mistakes
e. Written handbook

94. Who would like not use this book ?
a. Ability
b. Opinion
c. Suggestion
d. Approval
e. Hope

95. Mr. Tom : Ah miss Tina, sit down, please! Can you operate the Ms.Office program?
Miss Tina : Yes, Sir.
The underlined utterance is used to ask someone’s…..
a. Ability
b. Opinion
c. Suggestion
d. Approval
e. hope

96. Ida : Is Totok able to cook Japaness food?
Tia :Yes, he…..cook very well
a. can d. Must
b. will e. Should
c. May

97. Ria : Tommorow is Sunday.Shall we go swimming?
Lita :…..
Ria : Don’t worry. I will teach you
a. Oh, no. I am not going swimming
b. Well, I think I can Swim well
c. That’s a good idea to swim
d. I don’t like swimming
e. Well, I can’t swimming

98. Masto : How is you trip to New York?
Fini :……..
The expression of pleasure is..
a. Oh, I can’t stand with the flood
b. I am extremely displeased with the trip
c. I am feed up with the food
d. Fantastic
e. I don’t enjoy at all

99. A : What is your opinion about our new English teacher ?
B : …..
a. To me she is very good
b. On the contrary, I like her
c. I quite agree with you
d. I am happy to hear that
e. I see, She is a beautiful

100. A : Do you think John can solve the difficult problem ?
B : I…..he can do it. He is en intelligent student.
a. Am in doubt d. An not sure
b. Believe e. guess
c. Don’t think

101. Nanik:I think there is very little chance for me to save money at home.
Tini : To avoid the risk, it’s better for you to save it in the bank.
Drom the dialogue, we know that…
a. Nanik can certainy save her money at home
b. Nanik will probably no able to save money at home
c. Tini is certain that Nanik will save money at home
d. Nanik have saved her money in a bank
e. Nanik can save her money at home

102. Chika : What do you think about the film ?
Tata : The best we have seen this year, surely
Chika :…..the main characters are really amazing.
a. I don’t think so
b. I quite agree with you
c. I am afraid I don’t agree
d. I think you are mistaken
e. I couldn’t accept your opinion

103. A : I think….that the economic situation will improve soon
B : I agree
a. I can’t agree
b. I disagree
c. I can’t remember
d. That’s quite right
e. It is possible

104. Joko : I have never seen such a beautiful wedding ceremony.
Ali : …..it was really great
a. I got it know
b. I wouldn’t say that
c. I was very satisfied
d. I quite agree with you
e. I am verry happy to hear that

105. The people of this kingdom……her the princess
a. Appointed d. Nominate
b. Choose e. select
c. Crawn

106.

We can find the sign in…..
a. Circus d. door
b. Stasiun e. park
c. Bell

107. X :……
Y : Coordinator of the programme
a. they appounted him coordinator of the programme, didn’t they?
b. He was appointed coordinator of the programme , wasn’t he?
c. Did the bass appoint him coordinator of the programme ?
d. What did the boss appointed him?]
e. Who appointed him coorditaor of the programme ?

108. A : what do you think of government
liquidating of the cereval bank recently ?
B : I am one of the costumers of the liquidated banks, so …
a. I am one on it
b. I am aware of it
c. I am unhappy about it
d. I am sure about it
e. I am interested in it

109. …..there is snake behind you
a. Carefully
b. Mind you
c. Look out
d. Make suke
e. You shoul be

110. Toto : science and technology has develop very fast. Do you think we are reading for that?
Tati : …
a. Good, its interesting
b. Why not . just beheve yourself
c. Oh, marveollus, its great for you
d. Frangkly speaking. I disagree with you
e. I am not certain. The quality of our education it still now.

111. its already 03.00 pm lina a ten years old girl, has not come yet
tati : … something had happened to her
father : don’t worry. I am sure he is all right.
a. I am sorry
b. I am afraid
c. I am not sure
d. I don’t know
e. I don’t care

112. I saw you talking to Ani just now, and she has been crying since then. I am sure you have tod her something terrible.
The underlined words means….
a. Possibility
b. Ability
c. Uncertainty
d. Certainly
e. Impossibly

113. X : what do you think of this book ?
Y :………..
X : Yes, I think so. I like it very much and I have read it twice.
a. It’s boring, isn’t it ?
b. It’s interesting, isn’t it ?
c. It’s to expensive, isn’t it ?
d. I think it is very expensive.
e. I think it is too hard to understand, isn’t it ?
114. X : Do you know Ani’s phone number ?
Y : it’s 827293
X : Realy ?
Y : ….I phone her last night.
a. Yes d.Perhaps
b. May be e. Probably
c. Sorry

115. Budi : I like that Film very much ?
Rahmad : …I have seen it three times
a. So am I d. I don’t either
b. I am too e. Neither do
c. So do I

116. Rony : would you like me to swich on the light ? it’s very dark here.
Peter : Yes, please.
From the dialogue above, Peter expresses his...
a. Agreement d. Incapabily
b. Hope e. Ability
c. Disagreement

117. A : Do you thing they will be successful in the final exam ?
B : I can’t say that for sure.
From the dialogue above we conclude that is feels….
a. Worrid d. Uncertain
b. Unhappy e. Dissapoited
c. Hopeless


118. I know you have a lot of problems. But, you keep them yourself. I wis you…to me about it now.
a. Talk d. Talked
b. Had talked e. didn’t talked
c. Hadn’t talked

119. Deny : Were is your car Gus ?
Agus : In the garage….by machine.
a. It is prepaired
b. It is being prepaired
c. It was prepaired
d. It were being prepaired
e. It was being prepaired

120. Doni : I am sad. Masduki, my younger brother didn’t pass the final test.
Aisyah :He would have passed if he…
Doni : I se. He was not well prepared, then.
a. Had studied seriously
b. Has been studying seriously
c. Has studied seriously
d. Was studied seriously
e. Has been studied seriously

121. Faisal : Suf, your car always look shiny. Do you clean it yourself ?
Yusuf : No, I don’t. I always have it….
a. Clean d. cleaned
b. Clean ing e. Cleans
c. to Clean

122. Hendrawan : Za. Do you prefer playing badminton to playing football ?
Reza : I’d rather…..football.
a. Play d. Played
b. To Play e. I am Playing
c. Playing

123. If Joko’s father had a lot of money. Joko would have continued his study in USA.
From the sentences about we know that….
a. Joko’s father doesn’t have much money
b. Joko’s father don’t have much money
c. Joko’s father didn’t have much money
d. Joko’s father didn’t have much money so Joko will continue his study in USA
e. Joko’s father has much money so Joko will continue his study in USA

124. Salim : May I borrow you pen?
Ningsih : ….there is something wrong with it.
a. I am sad to hear that
b. I agree with you
c. I am sorry to hear that
d. I apologize
e. I am afraid you can’t

125. Daud : Sorry, I din’t come your party last Saturday night, because I had to pick my father up in the airport.
Sari : …..
a. It was really wonderful
b. Right you are
c. I don’t think you would
d. Not to worry
e. It is nice to hear it

126. Tourist : ….I can you tell me where the Botanical Garden is ?
Father : Yes, it is next to the City Hall
a. Hi d. Hello
b. Excuse me e. I am Sorry
c. I beg your pardon

127. Mona : I saw Hendi playing baskerball with his friens yesterday where as he attends a final test today.
Father : He…..
a. Were studying last night
b. Have been studying last night
c. Are studying last night
d. Should have been studying last night
e. Had been studying last night

128. Tony : Met, what would you do if you had a new car ?
Slamet : I think I would go around the city
From the dialogue above we know that Slamet ….a new car
a. Has d. Had
b. Have e. doesn’t has
c. Doesn’t have

129. Hamdani: Hi, bas. Glad to meet you! How are you getting on ?
Basuni : I have been passed from university on Indonesia
Hamdani : ……
a. I am sorry to hear that
b. You are welcome
c. It’s good
d. congratulation
e. thank you

130. Teacher : What time do you study everyday ?
Sri : I ussualy study from 06.00 to 10.00 in the evening
Dodi : what did the teacher ask you ?
Yuni : Ha ask me what time….
a. Do you study d. I was study
b. I studied e. I stidy
c. I am study

131. A clay is a malleable material.
This mean that it is…..
a. Easy to roll a malleable into a new shape
b. Easy to break into a new shape
c. Easy to cut into a new shape
d. Easy to fracture into a new shape
e. Easy to crack into a new shape


132. Dadang : Are you a new worked here ?
Edwin : Yes, I wonder to the office building when was it…..?
a. Build d. Built
b. Building e. Has built
c. Is building

133. Edi : What is the matter with Gito when he was in the class ?
Samsu : He nodes as if he had understand everything.
From the dialogue above we know that….everything
a. Gito understand
b. Gito doesn’t understand
c. Gito understanding
d. Gito didn’t understand
e. Gito understood

134. I prefer omelette…… fried chicken
a. Than d.more
b. To e. the most
c. Better than

135. Arman : Have you finished your job?
Rico : Yes, I finished three day ago. What about you ?
Arman : …..
a. I did
b. So do I
c. I will to
d. I have too
e. I too

136. father car was dirty and dusty, and father was very busy so….
a. Father had washed the car himself
b. Father had a workman wash the car
c. Father had to was the car
d. A workman had father was the car
e. A workman had the car washed by father

137. Arda : I am sorry for….your vase
Yeni : That’s alright.
a. Break
b. To break
c. Breaking
d. Broken
e. broke

Aku takut pada cermin.



Terutama pada setiap bayangan orang-orang yang terpantul di dalamnya…



Jika ada satu hal yang dapat kuenyahkan dari dunia ini, itu adalah pantulan bayangan. Entah itu di cermin, kaca mobil, ataupun benda-benda mengkilap lainnya yang dapat memantulkan bayangan setiap objek di dalamnya dengan cukup jelas.



Bayangan-bayangan tersebut sungguh membuatku gila! Tak jarang sumsumku berdesir setiap saat secara kebetulan aku melewati objek mengkilat. Terutama jika aku melihat bayangan orang lain selain diriku sendiri di dalam cermin tersebut. Mungkin hal ini dianggap aneh bagi kebanyakan orang. Tetapi apa yang terjadi tiga tahun yang lalu benar-benar telah mengubah hidupku sepenuhnya.



Waktu itu aku baru saja merayakan ulang tahunku yang kelima belas. Siang itu aku menemani salah seorang bibiku ke salon langganannya. Sebenarnya aku agak malas menemani bibiku yang satu itu. karena jika ia sudah keasyikan mengobrol, gempa bumi yang super dahsyat atau hujan batu pun tak akan menghentikan ocehannya yang super lengkap, dari isu seputar kenaikan BBM, gosip artis, sampai si Chiko yang suka menguber-uber anjing betina tetangga sebelah kami. Pokoknya ampun-ampunan deh bibiku yang satu itu.



Maka dengan berbekal komik, sebatang coklat, dan MP4 yang baru kubeli dua hari sebelumnya, akhirnya dengan setengah hati aku pun menyetujui untuk ikut bibiku ke salon. Nggak apa-apalah, pikirku, siapa tahu bibiku bersedia mentraktirku pizza sepulang kami dari salon nanti, sebagai upahku menemaninya hari itu.



Akhirnya setelah terkantuk-kantuk di dalam tuk-tuk (sejenis kendaraan umum di Thailand) selama beberapa saat, kami tiba juga di gedung bercat merah muda itu. Bangunan berarsitektur Portugis itu masih kelihatan seindah dan semenarik dua tahun sebelumnya, ketika terakhir kali aku menemani ibu dan bibiku ke tempat tersebut. Dengan dinding luar berbalutkan relief bunga teratai ungu dan merah, salon itu berdiri megah di tengah himpitan gedung-gedung perkantoran lain yang menjulang tinggi di sekitarnya.



Salon itu tidak sepenuh biasanya. Maklumlah. Mungkin karena hari itu hari Rabu pagi. Dari kaca jendela luar hanya terlihat beberapa orang remaja putri di dalam dan seroang nyonya muda yang sedang di-crembath. Syukurlah, kataku dalam hati. Moga-moga bibiku cepat selesai. Aku sudah tak sabar ingin menikmati pizza kegemaranku!



Begitu kami melangkah masuk, aroma wewangian khas Thailand segera menyergap kehadiran kami berdua. dan seorang wanita muda berbusana daerah menyambut kami dengan senyum ramahnya. Ia dengan sigap mengantarkan bibiku ke ruang sebelah dalam sementara aku segera memarkirkan pantatku di kursi empuk di sudut ruangan dan mengeluarkan MP4 biru mudaku. Detik berikutnya aku telah asyik terlarut dalam komikku sambil mengunyah coklat dan mendengarkan lagu.



Waktu berlalu dengan cepat. Kira-kira satu jam kemudian bibiku sudah hampir selesai. Ia sedang mematut-matut dirinya di depan cermin. Aku bangkit dari kursi dan menghampirinya. Sekilas aku melirik ke arah cermin. Pada saat itulah aku melihat sesuatu yang aneh.



Wajah penata rambut yang pada saat itu sedang menyemprotkan hair spray pada rambut bibiku terlihat menyeramkan. Pelipis sebelah kirinya terlihat mengucurkan darah dan membasahi kemeja putihnya. Aku tersentak kaget! Segera aku memalingkan wajah dari cermin dan memperhatikan sang penata rambut yang berdiri tepat di samping kananku. Tapi ia terlihat baik-baik saja! Tak ada luka sedikit pun pada wajahnya dan kemejanya putih bersih.



Aku mulai kebingungan. Aku kembali memandang cermin. Dan apa yang kulihat tetap sama dengan apa yang kulihat pertama kali. Wajah dan baju yang merah oleh ceceran darah yang mengucur semakin deras!



Aku tak tahan lagi! Aku segera mengubah posisi berdiriku agar aku tak dapat melihat bayangannya di cermin. Semua ini benar-benar membuatku gila! Apakah ada yang salah dengan penglihatanku? Ataukah ini hanya imaginasiku belaka?



Tak lama kemudian bibiku selesai dan kamipun pulang ke rumah melalui rute yang sama. Sepanjang perjalanan aku mengunci bibirku rapat-rapat. Pikiranku benar-benar kalut! Aku masih bingung dengan apa yang baru saja kualami.



Selang beberapa minggu kemudian, bibiku kembali ke salon itu untuk creambath. Pada saat itulah kami mendengar kabar bahwa salah seorang penata rambut salon tersebut telah meninggal dunia dua minggu sebelumnya karena kecelakaan mobil dan ia adalah penata rambut yang waktu itu melayani bibiku! Katanya sewaktu ia hendak pulang ke rumah pada hari itu, di tengah jalan ia tertabrak oleh seorang pengendara motor ugal-ugalan sehingga tubuhnya terpental ke aspal dan kepalanya terbentur keras sehingga darah mengucur dari wajahnya. Orang-orang segera membawanya ke rumah sakit terdekat, tetapi ia meninggal dunia dalam perjalanan karena luka-lukanya sangat parah dan ia mengalami pendarahan hebat di kepalanya.



Aku tertegun.



Mendadak aku teringat penglihatan yang kualami waktu itu. Apakah itu merupakan firasat akan terjadinya sesuatu? Aku berusaha melupakan peristiwa tersebut dan kuanggap hal itu sebagai suatu kebetulan belaka. Sampai beberapa bulan kemudian....



*****



Hari sudah siang ketika aku dan Irene, teman sekelasku, pulang dari sekolah. Rumah kami berdekatan, sehingga hampir setiap hari kami pergi dan pulang sekolah bersama-sama. Dalam perjalanan pulang kami memutuskan untuk mampir ke mal terdekat untuk membeli beberapa perlengkapan sekolah.



Sewaktu kami melewati sebuah butik pakaian, secara kebetulan aku menoleh ke arah kaca etalase. Dan napasku tersentak. Aku dapat melihat bayanganku sendiri di kaca itu, tetapi di sampingku bukan bayangan Irene, melainkan ayahnya. Ia terlihat pucat dan sedih.



Jantungku berdegup keras. Aku teringat kembali peristiwa yang kualami beberapa bulan sebelumnya bersama bibiku. Aku tak tahu apakah hal yang sama akan terulang lagi. Aku tak berani mengucapkan sepatah kata pun tentang hal itu padanya. Aku tak ingin ia sedih memikirkan hal-hal yang belum tentu akan terjadi.



Malam itu aku baru saja akan pergi tidur ketika tiba-tiba telepon berdering. Ketika kuangkat, terdengar suara Irene. Ia tersedu-sedu. Aku langsung merasakan firasat buruk. Di sela isak tangisnya, ia berkata terbata-bata,



"Phrai, ayahku ..." ia tak dapat melanjutkan kalimatnya. Ia hanya terisak pelan.



"Ada apa dengan ayahmu? Apa yang terjadi?" Mendadak aku merasa gugup dan tegang. Tanganku gemetaran. Pikiranku benar-benar kalut. Apakah ini…?



Tidak mungkin! Jangan!



Belum sempat aku berpikir lebih jauh, isakan Irene kembali terdengar.



"Ayahku tak sadarkan diri. Beberapa saat yang lalu ia mendapat serangan jantung. Kini ia sedang dalam perjalanan ke rumah sakit."



Aku tersentak kaget. Seketika tubuhku lunglai dan jantungku berdegup tak karuan. Oh Tuhan, jangan biarkan firasatku menjadi kenyataan,, doaku dalam hati.



"Irene, kita berdoa saja, semoga beliau tidak apa-apa," kataku sambil menarik napas panjang.



"Suster yang merawat ayahku mengatakan bahwa ayahku dalam kondisi kritis karena ia terlambat diberikan pertolongan," Irene berkata lirih sambil terisak-isak.



Aku tak bisa mengatakan apa-apa lagi selain menghibur sahabatku itu. Malam harinya aku berdoa semoga firasatku meleset dan segalanya akan baik-baik saja. Aku sungguh-sungguh berusaha menghibur diriku sendiri bahwa apa yang kulihat waktu itu di kaca etalase toko bersama Irene adalah halusinasiku saja dan tidak ada sangkut pautnya dengan apa yang telah terjadi pada ayah Irene. Tetapi semakin aku berusaha meyakinkan diriku sendiri, semakin besar keraguan yang tumbuh jauh di lubuk hatiku bahwa apa yang kualami sebelumnya tidak akan terulang kembali.



Keesokan harinya aku kembali mendapat kabar dari Irene. ia mengabarkan bahwa ayahnya telah meninggal dunia malam itu juga. Aku sangat sedih mendengarnya. Terlebih-lebih karena aku telah mendapat pertanda tentang hal itu sebelumnya namun tak ada yang dapat kulakukan untuk mencegah musibah itu. Apakah ini suratan takdir? Jika ya, apa gunanya aku mendapatkan firasat itu jika aku sendiri tak dapat melakukan apa-apa untuk mencegahnya? Mengapa? Mengapa? Beribu tanda tanya berkecamuk dalam benakku, namun aku sungguh tak kuasa untuk menjawab semua pertanyaan itu. Semua peristiwa ini benar-benar membuatku stres!



Semenjak kedua peristiwa itu, aku masih mendapat penglihatan-penglihatan lain yang sering kali membuatku dibayangi perasaan bersalah, sedih, dan takut. Tak jarang aku melihat bayangan-bayangan menyeramkan dari orang-orang di sekililingku yang tak kukenal. Entah itu bayangan pedagang sayur yang kebetulan lewat di dekatku, atau bahkan seekor kucing liar yang melintas di hadapanku. Semua bayangan mereka sungguh membuatku merana!



Aku hanya bertanya-tanya, kapan kiranya, suatu hari nanti, aku akan melihat bayangan kematianku sendiri. Apakah hari ini? Besok? Lusa? Ataukah tahun depan? Atau bahkan sesaat lagi?



Aku hanya berharap semoga aku siap menghadapi hari itu.



Hari ketika bayanganku menjadi kenyataanku…

Biological Component

BIOLOGICAL COMPONENTS

CELLS AND PROTOPLASM
2.1 History The finer structures of living organisms were unknown until after the invention of the compound microscope (about 1591). In 1665, Robert hooke reported that cork and other plant materials contained many small partitions separating cavities that the
He named cells. In 1824, rene dutrochet stated that “plants are composed entirely of cells, and of organs that are obviously derived from cells” and that the same applied to animals. In 1833, Robert brown described the nucleus as central feature in plant cells. in 1838, M.J. schleiden put forth the thesis that cells were the unit of structure in plants; in 1839, his coworker theodor schwann applied the thesis to animals. The generalization is known as the cell theory. Greater emphasis was given at first to the cell wall and less to the contents. In 1840 , purkinje named the cell contents protoplasm, research during the past century has axtended the theory and shown that the cell contents are more important the wall and that intercellular(between cell) material is produced by certain cells. According to the cell theory, all animals and plants are composed of cells and cell product. The cell is the fundamental unit, both structural and physiological, In all organism, and there is a constant exchange of matter and energy within cell in the process of living. In multicellular (many-celled) animals the cells are integrated for proper functioning, whereas in unicellular animal generally starts life as a single cell that devides repeatedly to form its body.
2.2 Protoplasm The living substance in the cells of all plants and animals is called protoplasm. It is complex mixture of various materials, including water, mineral salts, and many organic compounds. The latter are known in nature only as components or products of living organisms. In different species and in the parts and organs of any one animal the protoplasm differs in the chemical, physical, and biological properties. It has, however, certain common characteristics, which are discussed below.
Typically, protoplasm is a translucent, often grayish, slimy substance, somewhat viscous, but capable of flowing. Its structure has been variously considered to be 1. granular, 2.foam-like or alveolar, 3. an emulsion, or 4. fibrillar or reticular, of small fibers or threads. Actual differences in kind, difficulties in observing the fine details, and change incidental to removing protoplasm from living organisms, or the fixing of tissues for study are responsible for same differences in the interpretation of its structure.
Living organisms and the protoplasm of which they are composed are characterized by activity and change. A human being develops as an embryo, is born, grows, lives actively and dies. Within its protoplasm, is an animals, many metabolic processes are going on constantly. Constructive metabolism (anabolism) includes the synthesis of the products of digestion into compounds, often more complex, which are incorporated the ( catabolism, dissimilation), various components are broken down to simpler compounds, providing energy for work or heat, with consequent yield of waste products. Both types occur simultaneously in living protoplasm, but anabolic processes, leading to growth, predominate during embryonic, development and early life. Catabolic processes are in excess in the middle and later years of life.

2-3 The animal cell most animal dells are minute, and the units of measure used are the micron (nm) = 10 angstroms ( ). A millimeter or micron (m) and the Angstrom ( ). The relationships among these units and other metric units are as follows: 1 millimeter (mm) = 1,000 micrometers ( ); 1 micrometer ( ) = 1,000 nanometers (nm); [A millimeter = 0.03970 inch (in)]. Many cells measure 10 to 50 m in diameter. The cells with the largest diameters are the yolks of bird and shark eggs; that other chicken is 30 mm. some nerve cells in large animals are the yolks of bird and shark eggs; that or the chicken is 30 mm. Some nerve cells in large animals are over a meter in length. See Fig. 2-1

The animal cell (Fig. 2-2) is bounded by a cell membrane, or plasma membrane, which is a triple layered structure composed of protein and a lipid (fat-like substance). This membrane is continuous with the cells’ internal membrane systems such as the endoplasmic reticulum and the Golgi complex (Figs. 2-2, 2-3) The great similarity of the membranes of cell organelles of most types thus far investigated has led to the belief that all cell membranes have the same fundamental molecular construction, a concept

Figure 2-1
Relative sizes of some animal cells and parts of cells. Each major scale division is one-tenth of that above.
Visual microscope magnifies about 10 to 2,000 x : electron microscope about 5,000 to 100,000 x or more.

Called the unit membrane. The exact molecular arrangement of the protein and lipid molecules in this arrangement of the protein and lipid molecules in this unit membrane is still unresolved but is believed to be a sandwich of two layers of protein molecules surrounding a layer of lipid molecules (Fig. 2-2) The plasma membrane regulates cell permeability to various kinds of molecules and surrounds the cytoplasm that fills the cell interior. The cytoplasm is translucent and viscous and contains various finer structures and cell organelles (“little organs”) Most conspicuous of the cell organelles is a distinct dark body, the nucleus, commonly of spherical or ovoid form. It is surrounded by a distinct nuclear membrane that is continuous with the plasma membrane and is interrupted by nuclear pores that allow the contents to come in contact within the nucleus is the chromatin (Gr. Chroma, color) seemingly of isolated granules but actually parts of continuously spiraled filaments, the chromonema. During cell division, the chromatin becomes aggregated as visible rods, the chromosomes, which are capable of self-duplication through successive generations.

Chromosomes (Fig. 11-12) are of the greatest biologic importance, because they contain the elements (genes) directing hereditary transmission of characters (par. 11-19) The nucleus controls much of cell metabolism; if it is removed, the cell cannot continue normal activities and soon dies. An isolated nucleus cannot form cytoplasm. Each nucleus contains a spherical nucleolus (one or more), involved in nucleoprotein metabolism.



The cytoplasm contains several kinds of structures, cell organelles, some visible under the optical microscope and other shown only by the electron microscope. These organelles and structures are:
1. A spherical centrosome containing one or two dark-staining centrioles. The centrioles have a part in cell division.
2. Golgi complex (bodies or apparatus), often near the centrosome, composed of flattened sacs bounded by membranes continuous with the plasma membrane and thought to be involved in transport of materials in and out of the cell and possibly in certain biochemical reactions requiring membranes for localization of enzymes.
3. Mithochondria, seen as globules or round-ended cylinders or sacs 0,5 to 1 µm in size (fig. 2-4). They are covered by a membrane about 50 Ao thick with an inner membrane folded and projecting into the inner spaces; these inner folds are the site of enzymes directing metabolic oxidation (par. 2-29). The mitochondria also contain DNA, which is the genetic material, and a related substance called RNA (par. 2-27). The only other site of DNA in a cell is the nucleus.
4. Endoplasmic reticulum, which is a series of membrane-bounded vesicles of varying shape (fig. 2-4). The endoplasmic reticulum exists in two types, rough and smooth. Rough endoplasmic reticulum has numerous globular particles 100 to 150 Ao in diameter on its inner side. These particles are the ribosomes, the sites of protein synthetis. Smooth endoplasmic reticulum lacks ribosomes.
5. Microtubules, which appear as long, hollow fibers. They appear to be involved in the preservation of the shape of cells and in the machinery of motion, particularly in mitosis.
6. Lysosomes, which are membrane-bounded bodies containing hydrolytic enzymes.
7. Fat, as droplets or as yolk in egg cells.
8. Vacuoles, or vesicles, small cavities filled with either fluid or granular material.
9. Secretion granules, especially in gland cells, which are transformed to pass out as secretions.
Figure 2-2
Schematic diagram of an animal cell. Not all parts shown will be present or evident in any one cell, either living or fixed and stained. The insert shows diagrammatically the construction of a unit membrane.

Figure 2-3
Electron micrograph of an entire cell components. Section of ectoderm from a hydroid medusa (Aequorea), x 6000. A more representative mitochondrian is shown in fig. 2-4. Nucleolus shows only in nucleus at upper left. Micrograph by James H. Mc-Alear, Electron Microscope Laboratory, University of California, Berkeley.)







Studies of cells formerly dealt mainly with their physical features as seen in thin stained sections. In recent years, new methods of study and new tools of research have been devised by biochemists to learn the reactions constantly in progress in every living cell. The tiny cell is an amazing unit where many chemical substances undergo a wide variety of interaction and change-synthesis of new materials, use of food and energy to provide for movement, secretion, or other activities, and rendering of waste product into forms not harmful. Any cell is at least as intricate as an entire petroleum refinery that receives the mixture of hydrocarbons in petroleum, refines and modifies same for fuel and lubricants, and synthesizes many new and different organic compounds to serve various purpose in our modern everyday life.

Figure 2-4
Electron micrograph of part of rat pancreas cell, x 15000. Note the inwardly folded inner membrane of the mitochondrian. (Drs. Marilyn B. Farquhar and Stephen L. Wissig, University of California Medical School, San Fransisco.)


CELL DIVISION

Growth in organisms is accomplished chiefly by multiplication of cells. In the unicellular PROSTISTA, the animals themselves multiply; in other animals, the number of cells in the individual is increased.
2-4 Mitosis cells multiply chiefly by mitosis, a complex process that involves an equal division of the nuclear chromatin in both kind and amount (figs.2-5,2-6). Cell division by mitosis is common to all animals. Mitosis is active during embryonic development, in growth, in repair of injury, and replacement of body covering at motling. It is also the process, but study purposes, it is divided into several stages, as follows: (1) prophase, (2) metaphase, (3) anaphase, and (4) telophase. Cells not undergoing mitosis are said to be in the interphase. Duplication of the genetic material occurs in interphase.
PROPHASE The centrosome usually contains two centrioies (if there is only one, this divides); the two move to opposite sides of the nucleus. Around each centriole, fine, short, radiating fibers appear in the cytoplasm to from an aster; and other longer spindle fibers extend between the separating centrioles.
Meanwhile the chromatin within the nucleus be comes evident as distinct chromosomes that shorten, thicken, and stain deeply. Each chromosome is actually composed of two closely parallel, spiral filaments, the chormatids (daughter chromosomes). In the cells of any one species the several chromosomes are of characteristic size and shape-long or short, thick or thin, and shaped like a rod, a J, or a V. careful microscopic preparations show a construction or dot (centromere) where the two arms of the chromosome join; this is the point of attachment by spindle-fibers. Toward the end of the prophase, the nuclear membrane and nucleolus disappear, and the chromosomes become associated with spindle fibers and move toward the aquatorial plane of the cell.
The total number of chromosomes present at the end of the prophase is the diploid number. This is constant and characteristic in any species of animals, the chromosome number ranges from 2 to 250 but usually is less than 50.
METAPHASE The chromosomes lie radially in an equatorial plate across the cell midway between the two asters, each chromosome being connected to the spindle fibers. Other fibers extend continuously between the poles. The two halves of each chromosome become more evident.
ANAPHASE The halved chromosomes move apart, those of each group toward its respective pole(centriole). In living cells there is an active pulling back and forth of the opposing seta as they separate. Each daughter chromosome consists of an equivalent half of the genetic material formerly in one chromosome.
TELOPHASE As the groups of daughter chromosomes end their polar movement, they become less conspicuous, a nuclear membrane forms about each group, a nucleolus is produced in each, the centriole divides into two, and the spindle disappears. Finally a cell membrane appears across the former plane of the equatorial plate. When this has ended. The visible part of mitosis is complete. The chromosomes in each daughter cell revert to the net-like pattern of the interphase or metabolic cell.
The equal division of chromation whereby each daughter cell receives half of that in each parent chromosome is of great significance from the stand-point of heredity (chap. 11), since the genes, or determiners of hereditary characters, are believed to be carried by the chromosomes and to be duplicated with the latter. Such partitioning distributes identical lots of genes to all cells in the body.

TISSUES
The parts of any multicellular animal consist of different kinds of cells. Those similar structure and function are arranged in groups or layers known as tissues; hence multicellular animals (METAZOA) are “tissue animals”. In each tissues, the cells are essentially alike, being of characteristic size, form, and arrangement, and they are specialized or differentiated both structurally and physiologically to perform some particular function such as protection, digestion, or contraction, whence a division of labor results among different tissues. Histology, or microscopic anatomy, is the study of the structure and arrangement of tissues in organs, in contrast to gross anatomy, which deals with organ systems by dissection.
The cells in a multicellular animal may be divided into (1) somatic cell or body cells (and their products), constituting the individual animal throughout its life; and (2) germ cells, having to do only with reproduction and continuance of the species (Chap.10). there are four major groups of somatic tissues: (1) epithelial or covering; (2) connective or supporting (including vascular or circulatory) ; (3) muscular or contractile; and (4) nervous.
2-5 Epithelial tissues these cover the body, outside and inside, as skin and lining of the digestive tract (see Figs. 2-7, 2-8). The cells are compactly placed, bonded together by intercellular cement for strength, and often supported beneath on a basement membrane. Structurally the cells may be (1) squamous, or flat; (2) cuboidal ; (3) columnar; (4) ciliated; or (5) flagellated. The tissue may be either (6) simple, with the cells in one layer; or (7) straitifed,with multiple layers. Functionally, an epithelial tissues may be protective, glandular (secretory), or sensory.



Figure 2-6
Mitosis in egg (blastula) of whitefish. Prophase. (A) centrosome divides. (B,C) Centrosome at opposite poles, chromosomes become evident, nuclear membrane disappears. Metaphase. (D,E) Chromosomes centered on equator of spindle, and (E) each divides into two. Anaphase (F,G) Chromosomes move toward poles, spindle lengthens, cytoplasm of the two cells separated by cell membrane between. (Photomicrographs by Dr. hans Ris.) Compare Fig. 2-5.

Simple squamous epithelium is of thin, flat cells, like tiles in a floor; such cells form the peritoneum that lines the body cavity and the endothelium lining the inner surface of blood vessels in vertebrates. Stratified squamous epithelium forms the outer layers of the human skin (fig.3-1) and lines the mouth and the anterior partions of the nasal cavities. Cuboidal epithelium, with cube-like cells, is present in salivary glands, kidney tubules, and the thyroid gland. Columnar epithelium consists of cells taller than wide, with their long sides adjacent; this type lines the stomach and intentines of vertebrates (fig.2-7).
A ciliated cell bears on its exposed surface from one two many short, hair-like protoplasmic processes known as cilia. These beat in one direction, the adjacent cilia acting in unison, so that small particles or materials on the surface are moved along. Cuboidal ciliated epithelium lines the sperm ducts of earth-worms and other animals, and columnar ciliated epithelium lines the earthworm’s intestine and the air passages (trachea,etc.) of land vertebrates. The embryos and young larvae of many aquatic animals are covered with ciliated cells by which they are able to swim about. A flagellated cell (fig.16-3) has one or more slender, whip-like cytoplasmic processes or flagella on the exposed surface,; such cells line the digestive cavities of hydra and sponges.
Protective epithelium guards animals from external injury and from infection. It is one-layered on many invertebrates but stratified on land vertebrates. In the latter case, basal columnar cells (germinative layer) produce successive layers of cells by mitosis; this pass outward, flatten, and lose their soft protoplasmic texture to become cornified or “horny”, as they reach the surface (fig.2-8E). the epithelium on the earthworm, and other invertebrate animals, secretes a thin homogeneous cuticle over the entire exterior surface.
Glandular epithelium (fig.2-9) is specialized for secreting products necessary for use by an animal. Individual gland cells of columnar type (goblet cells) that secret mucus occur on the exterior of the earthworm and in the intestinal epithelium of vertebrates.
Epithelial cells specialized to receive certain kinds of external stimuli are called sensory cells. Examples are those in the epidermis of the earthworm (fig.20-3) and on the tongue and the nasal passages of humans (figs. 9-8, 9-9).

Figure 2-7
Photomicrograph of part of cross section of frog intestine (duodenum), showing how several kinds of cells and tissues are combained to form an organ.

2-6 Connective and supportive tissues These serve to bind the other tissues and organs together and to support the body (fig.2-10). They derive from embryonic mesenchymal cells with fine protoplasmic processes. Tissues of this group later become diverse in form; some produce fibers and other intercellular substance, whereby the cells are less conspicuous.
Reticular tissues is a network pf cells with stiff, interconnected cytoplasmic fibrils, the spaces between being filled with other types of cells; it makes the framework of blood-forming organs such as lymph glands, red bone marrow, and the spleen. Fibrous connective tissue consists of scattered cells, rounded or branched in form, with the intercellular spaces occupied by delicate fibers. The white (collagenous) fibers consist of numerous fine parallel fibrils, pale in color and often wavy in outline, forming bundles that are crossed on interlaced but not branched; they occur commonly in tendons and around muscles and nerves. The elastic fibers are sharply defined and straight, bent, or branched; they bind the skin to the underlying muscles, attach many other tissues and organs to one other, and are present in walls of the larger blood vessels and elsewhere. Both kinds of fibers occur in the wall of the intestine and in the deeper part (dermis) of vertebrate skin. In adipose or fat tissue, the cells are rounded or polygonal, with thin walls and the nucleus at the one side; they contain droplets of fat, which may form larger globules. Fat is usually dissolved out in prepared microscopic secions, leaving a framework of cell outlines.
A tendon is a bundle of parallel white fibers surrounded by a sheath of the same material, with in ward projections of the sheath that form septa, or partitions. Cartilage (gristle) is a firm yet elastic matrix (chondrin) secreted by small groups of rounded cartilage cells embedded within it and covered by a thin fibrous perichondrium. Hyaline cartilage is bluish white, translucent, and homogeneous; it covers joint surfaces and rib ends and is present in the nose and in the embryos for all vertebrates and in the adults of sharks and rays. It may become impregnated with calcareous salts but as such does not become bone. Elastic cartilage containing some yellow fibers is present in the external ears of mammals and in the Eustachian tubes. Fibrocartilage, the most resistant type, is composed largely of fibers, with fewer cells and less matrix. It occurs in the pads between the vertebrae of mammals, in the publics symphysis, and about joints subject to severe strains.
True bone or ossseous tissue occurs only in the skeletons of invertebrates. Bone is a dense organic matrix (chiefly collagen) with minerals deposits, largely tricalcium phosphate, Ca3(PO4)2 , and calcium carbonate, CaCO3; the mineral part averages about 65 percent of the total weight. Bone develops either as replacement for previously existing cartilage (cartilage bone) or follows embryonic mesenchymal cells (membrane bone). Both types are produced by bone cells (osteoblasts). The cells become separated by the hard, intercellular matrix but retain many be reabsorbed in part or changed in composition. During the life of an individual, the proportion of mineral gradually in creases and the organic material decreases, so that bones are resilient in early youth and brittle in old age.
A bone (fig. 3-4) is covered by thin fibrous periosteum, to which muscles and tendons attach. Within the periosteum are bone cells that function in growth and repair. The mineral substance is deposited in thin layers, or lamellae. Those beneath the periosteum are parallel ti the surface. Inside, only in mammalian long bones, are many small tubular concentric lamellae, forming cylindrical haversian systems, the wall of each being of several such lamellae with a central Haversian canal. The systems are mainly longitudinal, but cross-connect, providing channels for blood vessels and nerves to pass from the periosteum to the interior marrow cavity of a bone. Individual bone cells occupy small spaces, or lacunae, between the lamellae; these connect to one another by many fine radiating canals (canaliculi) occupied by the cytoplasmic processes. In flat bones, such as those of the skull and in the ends of long bones, the interior lacks regular systems and is more spongy, Cross sections made by sawing such bones show the bone fibers are arranged like beams in arches and trusses to resist compression from the exterior. A slice of bone ground microscopically thin will show the lacunae and canaluculi, which then become filled with air and appear black by refraction. The central cavity in a long bone is filled withy soft, spongy yellow marrow (containing much fat); the ends and spaces in other) bones contain red marrow, where blood cells are produced.

Figure 2-11
Structure of bone (en larged, diagrammatic). (A) sector of long bone in longitudinal and cross section. (B) there concentric lamellae around a Heversian canal as seen in a thinly ground cross section.

Pigment cells or chromatophores provide the color of many animals.
2-7 Vascular of circulatory tissues The blood and lymph that serve to trans port and distribute materials in the body consist of a fluid plasma containing free cells, or corpuscles (fig. 2-12; Table 5-1). Colorless white blood cells, or leukocytes, are present in all animals with body fluids; same have the function of “policing” the body by engulfing bacteria and other foreign materials. The process of engulfing materials is called phagocytosis, and cells that possess this ability are called phagocytes. Rious shapes. Certain white blood cells can move and change shape, hence are called amoebocytes (amoeba-like). The leukocytes of vertebrates can pass through the walls of blood vessels and invade other tissues of the body. Vertebrate blood also contains red blood cells, or erythocytes, colored red by a rates, either blue or red by dissolved respiratory pigment ( hemocyanin, hemoglobin, pigment, hemoglobin, that serves for transport of oxygen. Those in mammals are non nucleated, biconcave, and usually round, but in other vertebrates they are nucleated, biconvex, and usually oval. The fluid plasma transports most materials carried in the bloodstream; it is colorless in vertebrates, but the fluid plasma of some invertebrates is colored either blue or red by dissolved respiratory pigment (hemocyanin, hemoglobin, etc).

2-8 Muscular of contractile tissues movements in most animals are prodused by long, slender muscle cells (Fig.2-13) that contain minute fibers, of myofibrils. When stimulated, they shorten in length or length or contract, thus drawing together the parts to which the muscles are attached.

In striated muscle, the fibrils have alternate dark and light crossbands of different structure or density, producing a distinctly crossbanded or striated appearance; the dark bands shorten and broaden upon contraction. The cells are cylindrical, scarcely 50 m in diameter; but some measure an inch or more in length. Each cell is surrounded by a delicate membrane (sarcolemma) and contains from several membrane (sarcolemma) and contains from several to many long nuclei. The vertebrates have groups of striated muscle cells surrounded by connective tissue sheats which form muscles of various shapes. These sheaths either attach to the periosteum on bones or gather to form tendons by which the muscles are attached to the skeleton ( Fig. 3-5) The simultaneous contraction of many fibers couses a muscle to shorten and bulge, as easily seen in the biceps og the upper arm. Striated muscle in vertebrates is attached to the skeleton and hence is called skeletal muscle; being under conscious control, it is also termed voluntary muscle.


Figure 2-12
Human blood cells. Erythrocyte about 7,5 m in diameter. Nuclei of leukocytes are dark (Table 5-1)

Nonstriated or smooth muscle consists of delicate, spindle-shaped cells, each with one central oval nucleus and homogeneous fibrils; cells are arranged in layers, or sheets, held by fibrous connective tissue. Such muscle is found in the internal argans or viscera of the vertebrate body, as in the walls of the digestive tract, blood vessels, respiratory passages, and urinary and genetical organs; hence it is also called visceral muscle; not being under control of the will, it is also termed involuntary muscle. In some lower invertebrates the contractile and protoplasmic portions of a muscle cell are of distinct parts, as may be seen in nematodes (fig.17-10).
Nonstriated muscle is usually capable of slow but prolonged contraction; in mollusks, it forms the voluntary muscles of the body. Striated muscle can contract rapidly but intermittently and requires frequent rest periods; it occurs in the wing muscles of the swiftest flying insect, in the bodies and viscera of arthropods generally, and throughout the bodies of all vertebrates.
The heart muscle of vertebrates is called cardiac muscle; it has delicate cross striation, and the fibers are branched to form an interconnecting network. Cardiac muscle is striated yet involuntary; throughout the life of an individual, its only rest period is between successive contractions of the heart. of nerve cells or neurons. The neurons are of varied form (Fig. 2-14) in the systems of different animals and in the several parts of any one system. The individual neuron usually has a large cell body, a conspicuous nucleus, and two or more protoplasmic processes. In vertebrates, the process that transmits stimuli to the cell body is the dendrite, and that carrying impulses away from it is the axon. In some invertebrates, the processes may transit in both directions. In a large animal, an individual neuron may be several feet long. Bipolar cells have one denrite and a single axon. The dendrite is often short and usually multibranched (like a tree) near the cell body, whereas the axon may be short or long and is unbranched except for an occasional collateral fiber. A group of nerve-cell bodies, with their conspicuous nuclei, when outside the central nervous system, is termed a ganglion (plural, ganglia) A group of of fibers or processes, bound together by connective tissue, and occurring outside the central nervous system is a nerve. The central nervous system of animals consists of an aggregation of nerve cells and fibers. Among these is the neuroglia (or glia), of several cell types, that seems to serve as delicate packing to hold neurons apart and may also aid in nutritions of neurons. Nerve fibers are sheathed by special cells called Schwann cells. Nerve fibers without any surrounding lipid coat are termed nonmyelinated (nonmedullated) and are gray in appearance. A myelinated fiber has the axon surrounded by a sheath of myelin containing fatty material secreted by the schwann cells and appears white. A delicate membrane or neurilemma, composed of schwann cells, surrouns both types of fibers. The lipid insulation of the nerve fibers serves to speed nerve transmission. The neurilemma sheath seems to play an important role in the regeneration of damaged nerve fibers. The myelin substance is constricted at interval, forming the nodes of Ranvier, which mark the boundaries between successive Schwann cells. Nonmyelinated fibers are common among invertebrates; among vertebrates, they are found in the sympatheic system and in certain fiber tracts of the spinal cord (internally) and brain (externally). In nerves and on the outside of the spinal cord, the myelinated fibers give those parts a whitish appearance. Transmission of nerve impulses is faster in myelinated then in nonmyelinated fibers.

ORGAN SYSTEMS

Every animal, small or large, must carry on a variety of essential functions (Fig. 2-15). Basically, these may be reduced to growth, maintenance, and reproduction; all other functions serve these major needs. Actually, the bodily operations are complex.

2-10. Organ systems in the various graups of the Animal kingdom, from lowest to highest, there is progressive increase in bodily complexity to carry on these functions. A series of bodily systems has evolved to serve the various needs. These and their principal functions are as follows:

1. Body covering or integument-protection from the environment.
2. Skeletal system-support (and protection) of the body.
3. Muscular system-movement and locomotion.
4. Digestive system-reception and preparation of food ; egestion of wastes.
5. Circulatory system-transport of materials.
6. Respiratory system-exchange of oxygen and carbon dioxide.
7. Excretory system-disposal of metabolic wastes and excess fluid.
8. Endocrine glands or system-disposal of internal processes and adjustment to exterior environment.
9. Nervous system (and sense organs)-regulation of internal processes and adjustments to exterior environment.
10. reproductive system-production of new individuals.


Many of invertebrates and all the vertebrates have the systems just mentioned. In some cases, functions are performed without special structural parts being present. Cnidarians, for example, lack respiratory, circulatory, and excretory organs, and the flatworms and roundworms have no circulatory or respiratory organs. An organ that continues in use maintains its efficiency, but if unused it tends to degenerate. In sedentary animals and many parasites various organs have disappeared. Thus, the tape worm, which absorbs nutriment directly from it host, has no digestive tract; and insect such as fleas, lice, and others of burrowing or parasitic habits have no wings.





BIOCHEMICAL ASPECTS

2-11 Chemistry of the animal body The substances and processes in living matter once were thought to differ from those in rocks, minerals, and other inanimate materials. This was disproved in 1828 when urea, an excretory product of animals, was produced from the inorganic substance, ammonium cyanate. In subsequent years, much has been learned of the chemistry of life. Many organic compounds have been synthesized in the lab oratory, some exactly like those in plants or animals and many other unknown in nature. The intricate reaction of organic substances have gradually been determined and understood. Biochemistry studies the compounds present in living cells and fluids and seeks to understand the phenomena we call life. Molecular biology is unraveling many of the finer detailed aspects of cellular function (pars.2-31, 11-19).

PHYSICAL PROPERTIES
2-12 Matter, weight, and gravity The substance of the universe, the earth, and living organisms is termed matter. Under different conditions of temperature and pressure, any particular kind of matter may be in one of three physical states-solid, liquid, or gas. Water may be variously solid ice, fluid water, or water vapor. Animal shells and skeletons are mostly of solids, and blood plasma and much of the content of body cells is fluid, and gases are present in lungs or dissolved in body fluids. Almost any animal comprises matter in three states.
The mass or quantity of matter in any object or body is a basic attribute. Certain forces attract any two bodies of matter, the degree of attraction being dependent upon their masses and distance apart. The attraction between the earth and that of any animal or other object on or near its surface is termed gravity, and the value of this force is its weight.
The force of gravity keeps animals against the surface of the earth or any solid object on which they may be. It acts more rapidly in air than in a denser medium, such as water, where resistance to movement is greater. The weight of any given animal would be less on the moon (small mass) but much greater on Jupiter (larger mass). The volume relation of weight of any object in reference to some standard (such as water) is termed its specific gravity. That of a gas is low, whereas that of metals, such as iron or gold is high. Among animal, specific gravity, and particularly the surface-volume realitionships, determine their habits and influence the type of environment in which they can live. Bats, birds, and insects are able to fly because of their extensive wing surfaces, and some aquatic invertebrates swim and float readily because they have much surface in relation to weight. The effective specific gravity of any aquatic animal is less than that of a comparable land dweller because the former is buoyed up by the weight of water it displaces.
Because of another property of force, inertia a body at rest tends to remain so, and one in motion tends to continue in motion. Inertia is directly related to mass. A child’s wagon requires less force to start into motion (overcoming inertia) than an automobile , but the wagon meets more surface resistances to motion and tends to stop sooner than the heavier vehicle. The some is true of animals. An insect has less inertia than a bear, hence it can start and stop more quickly. In the absence of gravity and friction with the air, water, or ground, a body once set in motion would continue on indefinitely; but on the earth, resistence of the surroundings eventually overcomes the inertia of movement. Any animal, large or small, must exert propulsive power to remain in motion.
2-13 Cohesion and adhesion for particles of matter of submicroscopic size (molecules; see par. 2-15) other forces operate: that of cohesion tends to keep particles of the same kind together and that of adhesion groups particles of different kinds. Cohesion of molecules at the surface of a body of water (or other fluid) produces an elastic skin-like effect termed surface tension that tends to make the surface minimum in extent. This tension has an appreciable elastic streght; it will support a clean needle laid on the surface. Water striders and other insects can “walk” on the surface film because their feet are covered by a nonwettable wax that does not break the cohesive force. Surface tension rounds up rain water as drops, and microscopic amounts of oil within animal cells are formed into spherical droplets by this force. Adhesion and surface tension are responsible for the rise of fluid in a fine capillary tube. An insect that falls with its wings on the surface film of a pool may be unable to rise again because of adhesion between its wings and the water.
2-14 Energy Another important basic component of our universe is energy, “the capacity to do work”. All activities of living organisms involve energy; examples are the move ments of animals, digestion and use of food, and transmission of nerve impulses. Energy may be manifested in several ways: motion, such as the flight of an insect; heat, an increase in temperature ( due to random movement of particles with in matter); chemical change or reaction as in the digestion of food; electric current, flow of impulses along the course of a nerve; and light. Transmission of units called photons, all these forms, which are more or less interconvertible, are termed kinetic energy, the energy of motion (Gr. Kinein, to move). A second kind is potential energy, the energy of position. An upraised hand or foot has potential energy, but as it swings to throw or kick a ball, this is converted to the kinetic energy of motion. According to the Einstein equation (e=MC), matter and energy are interconvertible, but this is a phenomenon of nuclear fission, and such as atomic energy, a third type, is rare in living organisms.
Two basic laws govern all energy conversion. The first law of the thermodynamics states that in any closed system the total quantity of energy remains unchanged. In an animal, the total received in food is expended in movement. None has actually been “lost” to the system of which the animal is a part. The second law of thermodynamics holds that heat is the end form of all energy transformations and that all forms of energy may be entirely transformed into heat, but that heat may never be transformed completely into the other forms. The energy received by an animal is variously converted in motion, friction, chemical conversion, or even nerve impulses finally becomes heat that is lost to its environment.
The energy in the world, in the last analysis, all derives from the sun. solar radiation is responsible for the development and growth of plants, upon which in turn practically all animals depend (Chap.12).
2-15 Structure of matter in everyday experience we learn to recognize some of the thousands of kinds of matter or substances to which names are given-water, iron, sugar, etc. mere inspection, however, will not show whether any particular substance is pure-of one kind-or a mixture of two or more. Ordinary water, for example, usually contains both oxygen (a gas) and salts (solids) in solution. To learn the actual properties of water alone, it must be rid of other substances. The science of chemistry deals with structure and composition of substances and with the reactions that these materials undergo.
Chemical research has shown that each kind of pure substance consists of ultramicroscopic structural units called molecules. In turn, each molecule is made up of one or more chemical elements. An element is a material which cannot be broken down into simpler form by ordinary chemical means. The particles of an element are termed atoms of an element are similar. A molecule of water consists of two atoms of the element hydrogen and one of the element oxygen. For convenience in stating chemical facts and describing chemical reactions, the names of elements are represented by symbols: H for hydrogen, O for oxygen, c for carbon, and so on. The formula for the water molecule is therefore H2O, that of the gas oxygen is O2, and that of common table sugar is C12H22O11. In all, 92 naturally occurring chemical elements have been identified, named, and studied. An additional 11 have been a total of 103.
By indirect methods, we have learned that atoms, in turn, are composed of even smaller particles. No one has been able to see the ultraminute molecules, atoms, or lesser components; but many careful physical experiments and calculation have made it possible to count and other data, the structural makeup of molecules and atoms has been visualized, and models of many have been made.
2-16 Atoms the atom is generally considered to have a spherical outline with a central nucleus around which one or more particles, called electrons, revolve in an orbit (fig. 2-16). The makeup of an atom thus roughly resembles our solar system with its central sun (nucleus) and revolving planets (electrons). In both, there is a vast amount of space between the components. If an atom were enlarged to a sphere 100fit in diameter, the nucleus would be perhaps ½ in through. Around the nucleus, electrons would be whirring so fast as to be a faint blur.
The nucleus is composed of protons, each of which bears a single positive charge, and also neutrons, which are uncharged. For every positively charged proton in the nucleus, there is an electron, negatively charged, in one of the orbits. The entire atom, therefore, is neutral, since the positive and negative charges are equal.
The atoms of the various chemical elements differ from one another in the number of neutrons, protons, and electrons each contains (fig. 2-17). The combining of chemical elements to form compounds (molecules)rests on the transfer or sharing of electrons between one kind of atom and another (fig.2-18).
Different kinds of atoms contain from one to seven concentric orbits, or shells, each with one or more electrons. The elements can be arranged in a periodic table according to the number of proton; therefore its atomic number is 1;helim has 2;sodium has 11; and so on. The atomic weight is an arbitrary number assigned to each kind of atom with reference to carbon, (12) as a standard. It is approximately equal to the sum of the number of the protons and neutrons in the nucleus. The electrons is practically weightless. Sample atomic weight are hydrogen, 1; carbon, 12; sodium, 23; uranium, 238.
All atoms an element have the same atomic number but not the same weight because some contain more neutrons than others. An isotope has essentially the same chemical properties as the original elements but differs in atomic weight; certain kind of isotopes release electrons or other electromagnetic radiation and hence are radioactive. Some of these can be produced artificially and some occur in nature. Carbon 14(atomic weight) is an isotope essentially like its “parent”, carbon 12, but is radioactive; it can be incorporated into a carbon-containing substance that is fed to or injected into an animal, and the course of that type of atom can be traced in its passage in various parts of the body by means of a device to record radioactivity such as a Geiger counter. Other isotopes become radioactive through release of nuclear energy (gamma radiation). Research with isotopes in plants and animals is serving to reveal some of the most intimate and fundamental details of their chemical processes.
2-17 Ions, electrolytes, and compounds When the outer orbit contains fewer than half the total number of electrons that it can hold, it may lose one or more; if it contains more than half, it may gain electrons. A change in number of electrons change the electrical nature of then atom-gaining electrons it becomes negative, but losing any it becomes positive. An atom thus changed is termed an ion; with an excess of electrons it becomes an anion (having a negative charge; in an electric field it moves toward the anode or positive pole); with a deficit it becomes a cation (going to the cathode or negative pole). A substance formed by the joining of two or more different kinds of atoms or irons is a compound (fig. 2-18). The combination of water with a chemical compound dissolved in it is called a solution. A compound which dissociates into anions and cations when dissolved in water froms a solution which will conduct an electrical current. Hence any chemical compound which will dissociate into ions is called an electrolyte. Any chemical compound which will dissociate

Figure 2-17

First parts of the periodic table diagramming the structure of atoms. The central represents the nucleus and its net positive charge-the atomic number. Small black dots represent planetary electrons, negatively charged, in their respective orbits. The atoms shown include those of elements common (C, H, O, N) or essential (Na, P, etc.) in living matter; still other are present in minute amounts as trace elements (Fe, Si, etc.). five kinds of atoms are omitted between calcium and iron.

NERVOUS SYSTEMS , SENSE ORGANS , AND ANIMAL BEHAVIOR

SISTEM NERVES, ORGAN/ BAGIAN BADAN [PERASAAN/PENGERTIAN], DAN PERILAKU BINATANG

 

 

All living protoplasm is irritable. Because of this, every organism is sensitive to changes of stimuli from both it's external environments ; to these it responds or reacts in various ways. Every type of organic response , from the simplest action of an amoeba to the most complex bodily function or metal process in humans, result from this fundamental characteristic of excitability. To perceive stimuli, to transmit these to various body parts, and to effect responses, most animals have sense organs and a nervous system (fig. 9.1) this system (together with endocrine glands in some) serves also to coordinate and integrate the functions cells, tissues and organ system so that they act harmoni ously as aunit, resulting in what we see as the behavior animals.

 

Semua protoplasma hidup dapat menimbulkan amar. Oleh karena ini, tiap-tiap organisma adalah sensitip ke perubahan stimul dari kedua-duanya adalah lingkungan eksternal; ke ini [itu] menjawab atau bereaksi dalam berbagai jalan. Tiap-Tiap jenis tanggapan organik, dari tindakan yang paling sederhana dari suatu amoeba kepada fungsi [yang] jasmani yang paling rumit atau proses metal di (dalam) manusia, diakibatkan oleh karakteristik pokok sifat dapat dirangsang ini. Untuk merasa stimuli, untuk memancarkan ini [bagi/kepada] berbagai komponen badan, dan untuk mempengaruhi tanggapan, kebanyakan binatang mempunyai organ/ bagian badan [perasaan/pengertian] dan suatu sistem nerves ( gambar 9.1) sistem ini ( bersama-sama dengan endocrine kelenjar/penekan dalam beberapa) melayani juga untuk mengkoordinir dan mengintegrasikan sel fungsi, organ/ bagian badan sistem dan jaringan/tisu sedemikian sehingga mereka bertindak harmoni [yang] ously sebagai unit, menghasilkan apa yang [kita kami] melihat sebagai binatang perilaku.

 

Any physical or chemical change capable of exciting an organism or its parts ia a stimulus. Common external stimuli derive from temperature, moisture, light gravity, contact, pressure, oxygen supply, salt concentrations, and odors (chemical emanation). Internal stimuli result from the quantity of food, water, oxygen, ar wastes in the body and from fatigue, pain , disease, or other conditions,. Some stimuli act directly upon cells or tissue and elicit a direct response ( e.g., sunburn), but most animals have various kinds of specialized receptors (sense organs) to receive stimuli.

 

Manapun bahan kimia atau phisik ber;ubah untuk mampu kegairahan [adalah] suatu organisma atau komponen nya ia [adalah] suatu stimulus. stimuli Eksternal umum berasal dari temperatur, embun, [cahaya/ ringan] gaya berat, kontak, tekanan, oksigen menyediakan, menggarami konsentrasi, dan bau ( pancaran kimia). Stimuli internal diakibatkan oleh kwantitas makanan, air, oksigen, ar menyia-nyiakan badan dan dari kelelahan, sakit, penyakit, atau kondisi-kondisi lain,. Beberapa stimuli bertindak secara langsung [atas/ketika] jaringan/tisu atau sel dan menimbulkan suatu tanggapan langsung( e.g., kulit menggelap terbakar matahari), tetapi kebanyakan binatang mempunyai berbagai macam [dari;ttg] sel yang peka rangsangan khusus ( merasakan organ/ bagian badan) untuk menerima stimuli.

 

a receptor is a cell or organ having an especial sensitivity (lowered threshold) to some particular kind or kinds of stimulus, as the eye to light and the ear sound. Exteroceptors receive stimuli from the external environment, and interoceptors from within the body, as with hunger or thirst. (see also proprioceptors, par. 9-14.) A stimulus causes the receptor to generate nerve impulses whivh travel along nerves to the central nervous system; the latter integrates the sensory information and the initiates impulses whih excite terminal structures, or effectors (muscles, glands), to bring about responses.

    Some stimuli are gradual, and response is slow, as in the chilling that precedes a sneeze, like the jab of a pin. Beyond a certain minimum there may be no quantitative relation between the intensity of a stimulus and the kind or magnitude of a responses that it produces (that aa-or-none-effect); this depends upon the kinds of cell or organs excited and their physiological condition. Several weak stimuli in rapid succession may bring a responses although each individually is too slight to do so; this is called this summation effect. Uon being excited, muscles contract produce movement, and gland cell pour forth the secretions previously synthesized witin them.

 

NERVOUS SYSTEM

 

 

9-1 Neourons and nerves nervous system are composed af nerve cells, or neurons, with cell processes known as dendrites and axons. Dendrites transmit impulses toward the cell body and axon away. The Neurons are varied form (fig. 2-14)in the system of different animal and in the several parts of any one nervous system. Each neuron is a distinct anatomical cell, having no protoplasmic continuity with other neuron, and also physiologically distinct. Injury to the nucleus or cell body destroys a neuron but does not always effect adjacent neurons. The neuron Is the functional unit of the nervous system, which consists chiefly of neurons in orderly arrangement. They comprise about 10 percent of the cell in the huan nervous system. The remainder are gliacell , which are not excitable but which support the neurons physically, probably also sustain them metabolically, and are believed to participate actively in barin function. Between any two neurons related in function there is delicate contact , or synapse ; this is a "physiological valve" that passes nerve impulses in only one direction, from the axon of one neuron to the dendrite of the other. A nerve consists of one to many nerve fibers (axons or dendrites) bound together by connective tissue and including blood vessels to supply nutrients and oxygens.

9-2 The nerve impulse the Impulse, or acion potential, that passes along a nerve fiber involves both chemical and electrical change. It requires energyand the presence oxygen, and produces a minute but measurable amount of carbon dioxide, and also a rise in temperature. The impulse moves at a uniform speed with the same intensity throughout. A wave of electrical change accompanie the impulse.

    The resting nerve fiber (neuron) is electrically polarized. The outside of its semipermeable membrane is relatively positive, and the inside a negative. What causes the polarization, and how is it maintained? The numbers of positive and negative ions are about the same outside and inside cell, but the concentrations of some ion siffer greatly. There are about 10-15 times more sodium (Na⁺) ions in the extracellular fluid than inside the neuron. Potassium (K⁺) ions, however, are about 30 timesgreather within than without. Movement of both by diffusion and active transport and permeability characteristics of the cell membrane can account for the potential difference. Na⁺ ions tend to diffuse inward K⁺ ions toward in the direction of their concentration gradients. The membrane of a resting cell, however, is less permeable to Na⁺     than K⁺ ; this and the concentration difference causes Na⁺ to enter more slowly than K⁺ leaves. The result is an excess of negative ions within and of positive without. The differences in the concentration gradients would gradually sisappear were is not for a preseumed"ion pump" of carrier molecules within the cell. By active transport, the pump is thought to move Na⁺ ions the cell surface, where they are expelled as fast as they "leak" i. K⁺ ions are taken from the surface into the cell.

 

    How is the nerve impulse transmitted? If a sufficient stimulus is applied to the cell membrane, it becomes depolarized at the palce stimulated, and a self-propagating wave of depolarization spreads outward in the membrane. The cell produces a current pulse of its own that amplifies the original stimulus. The immediate effect is to increase Na ⁺ permeability, and the flow of Na⁺ ions into the cell promptly increases. Flow of other Na⁺ ions is prompted, and inward movement of all these positive ions locally reduces part of the exceee negative charge inside—further reducing voltage differences across the cell membrane. When voltage declines to impulse threshold level, Na⁺ ions enter in such quantity that the internal potential becomes positive. The nerve impulse so initiated changes membrane permeability immediately ahead, so that Na⁺ ions enter in a progression to the end of the cell. The membrane returns to the resting state soon after the impulse has moved on. Polarization is restored by an outward surge of K⁺ ions shortly after influx of Na⁺ ions, restoring the original internal negative change.

    A neuron has an all-or-none response. If a stimulus is of threshold level, the impulse travels the length of the neuron at constant speed and uniform amplitude. Connecting a galvanometer at two points on an exposed nerve will show the current flow, or action potential. As an impulse passes, there is an abrupt peak, or spike, then a slower declines. Following the pek there is a refrectary period (0.001 to 0.005 second) during which the depolarized fiber cannot respond to another stimulus.

    A nerve impulse travels 6 to 12 m/second in a lobster, 28 to 30 m/second in a frog, and up to 120 m/second insome mammalian fibers. Transmission is slower in nonmyelinated fibers than in tjose with a myelin sheath, and slower in small fibers. There is a short delay in passage at each synapse. An impulse, upon reaching the finely branched end of an axon, causes the latter to increase the secretion of a chemical transmitter(or neurohumor) which sets up an impulse in the next neurons. Acetylcholine is produced n many synapses, including those at the neuromuscular junction. In at least some sympathetic synapses the transmitter substance is epinephrine neropinephrine. The increased emounts of acetylcholine would continue to stimulate the next neuron but for the fact that an enzyme, cholinesterase, quickly inactivates it.

 

    Sensory or afferent neurons are those which conduct impulse from receptors to or toward the central nervous system; and motos or efferent neurons conduct from the central nervous system to various effectors. Still other adjustor neurons in the brain and nerve cord join variously between sensory and motor neurons. Some nerve contains only sensory fibers, others only motor fibers, and many are mixed nerves including both types. A ganglion is a unit containing the cell bodies of few or many neurons, and certain ganglia in the brain are known as centres.

9-3 invertebrates nervous system (fig. 9-1) most protozoans show no structures for coordination, but some ciliates such as Paramecium have a definite system of fibrils or a neuromotor apparatus (fig. 15-13 B) ; this evidently receives stimuli, conduct impulses , and coordinates movement of the cell body. In sponges the cell about the openings (oscula) in the body wall contract slowly if touched, but these seem to be local responses without true propagation to nearby cells. There are no definite nerve cells or structures. Hydra and other cnidarians have a diffuse nerve net around the body in or under the epithelium, but no central ganglion. The net is composed of nerve cell, which are unlike typical neurons in being joined to on another by protoplasmic processes. They connect to both receptors (modified epithelial cells) in the epidermis and to the bases of epitheliomuscular cells thet contract slowly to alter the body shape. Nerve net also occur in ctenophores, echinoderms, enteropneusts, and ascidians and even on the blood vassels of vertebrates.

     In bilaterally symmetrical animals the nervous system is linear, usually comprising one or more pairs of ganglia or a brain in the anterior end joined to one or more nerve cord that extend posteriorly through the body. The nerve cord of invertebrates are all vertal and solid, and nerves pass from the ganglia and cords to various organs. Flatworms usually ( Fig. 17-1) have two anterior ganglia, with nerves to the head region, and two separated nerve cords which are joined by cross-connectives. In mollusks, annelids, and artrhopodos the paired anterior ganglia lie above and below the esophagus and are joined by connectives. The more specialized mollusks lack vetral nerve cord but have large ganglia joined by connectives in the head, foot, and viscera. In annelid worms and the more primitive artrhopods, including some insects and their larvae, the two ventral nerve cord have a pir of ganglia and a pair or more of nerves in each body segment. In the higher crustaceans, insects, and arachnoids the vetral ganglia are concentrated anteriorly. The starfish and other echinoderms have a radially arranged nervous system in keeping with their symmetry.

9-4 vertebrate nervous system in all vertebrates the nervous system ha a comparable embryonic origin (par. 10-17) and is always single, hollow, and dorsal to the digestive tract. In basic pattern is consists of (1) the central nervous system with a large anterior brain ( fig. 9-2) connected to a spinal or nerve cord and (2) the peripheral nervous system of 10 or 12 pairs of cranial nerves from the brain ( Table 9-1), a pair of spinal nerves from the accord for each primitive body segment, and the autonomic ( or sympathetic ) nervous system (fig. 9-5)

    9-5 Brain the Brain is housed in the "brain box" or cranium. In dorsal view it includes, in lower vertebrates, (1) two olfactory lobes with nerves to the nasal chambers; (2) two cerebral hemispheres closely joined to the preceding and also attached to (3) the median dienchepalon . behind this are two rounded optic lobes , supported on (4) the midbrain below, and followed by (5) a small traserverse cerebellum ; this is over (6) the open-tooped medulla oblongata, which tapers to join the spinal cord (fig. 9-2). The diencephalon has a dorsal pineal body or epiphysis. Below the diencephalon is the optic chiasma ( crossing of the optic nerves) , followed by the infundibulum as a blunty triangular outgrowth with the hipophysis , or pituitary gland, at its posterior end.

The cavities within the brain are the first and second Ventricles in the cerebral hemispheres; these connect to a third vertical in the diecephalon. From the latter a small aqueduct of sylvius lead to the fourth ventricles located in the medulla. The fourth verticles is continous with a minute central canal throught the spinal cord. Cerebrospinal fluid fills the ventricles and other cavities and surrounds the brain. Metabolic exchanges for the brain are perfomed by arteries and veins over its surface and the by two dense network af blood vessels, the anterior choroid plexus over a dorsal opening in the diechepalon and the posterior choroid plexus above the medulla. The brain and spinal cord are surroundby two membranes, a thicker dura mater adhering to the enclosing bones and a delicate pia mater close over ther nervous tissue it self. Ten pairs of cranial nerves extend from various parts of the brain to sense organs, muscles, and other structures ( Table 9-1). In the adult shark and frog the parts of the brain are in linear arrangement ( Fig. 9-2 ). In higher vertebrates this primitive brain stem becomes folded ar flexed, and the cerebrum and the cerebellum become progressively enlarged ( Fig. 9-2) until in mammals and especially in humans ( Fih. 9-3) the cerebrum overlies all other parts. Furthermore, the outermost gray mater, or cortex, of the cerebrum is both thickened and increased in areas, so that it becomes folded or corvoluted. In humans it contains several billion neurons and their synapses comprising about three-fourths the weight of the entire nervous system. It is importantly involved in awareness of sensations and actions, in registering memories, and in motivation, but all these metal attributes are also influenced by other parts of the central nervous system. Destruction of cortical areas other than motor, sendory, or language centres does not always result in obvious behavioral changes. Three major association areas, frontal, temporal, and parieto-accipital, interconnect cortical regions. Memory pertaining to sensory experience may be stored in association areas. For example, the receptive area for sight provides awareness of the colors of a painting, but the adjacent visual association area is required for its recognition as a landscape. The increase in the bulk of the cortex among the higher vertebrates is in keeping with their greather metal abilities. There is, is however, no exact correlation between brain size and intelligence. The cerebellum is involved with coordination of movement and posture. It show special sevelopment in animals whose movements are quick and require precise coordination.

    9-6 Spinal cord and nerves (Fig. 9-4) The outer White matter of the spinal cord consists of bundles of mylinated fibers connecting between various parts of the brain and the nuclei of spinal nerves and adjustor neurons. The inner gray matter contains adjustor neurons and the nuclei of motor neurons; nuclei of sensory neurosn are in the dorsal
root ganglia of spinal nerves. If dorsal root of spinal nerve is cut, any sensory impulses from the entering fibers fail to reach the cord and brain. Destruction of the ventral root block all motor control by fibers I that nerve. The ventral root are variously injured or destroyed in poliomyelitis, leding to impairment of muscular function.

 

Dalam Hujan

Surat dalam Hujan

Cerpen Rohyati Sofyan Dimuat di Suara Karya 11/16/2008HUJAN. Selalu demikian di bulan Nopember ini. Hujan benar-benar mewarnai hari. Sore. Ya, pukul empat lebih, hujan seperti pantulan manik-manik kaca menderas seketika dengan anggunnya. Aku menyesal, sumur di luar pasti akan keruh lagi airnya, mestinya diberi atap nanti. Hujan. Aku duduk di sini, dekat jendela kaca memerhatikan curahan air yang mengguyur serentak dari udara. Seperti apakah bunyinya? Di atas atap, di dedaunan, di tanah becek, bahkan di kolam ikan yang berderet nun di luar? Aku tak tahu. Sunyi. Kecuali gelegar petir yang menghantam bumi. Ya, hanya itu yang kurasakan. Aku ingat kamu. Aku suka hujan, aku suka suasananya yang begitu kontemplatif. Kurasakan ekstase tertentu jika hujan. Memberiku inspirasi untuk menulis puisi. Bahkan juga menulis surat untukmu dalam suasana hujan kupikir cukup romantis, meski isinya terkadang bernada humor yang ironis. Aku rindu suratmu. Yang selalu hangat dan menggembirakan, simpel dan terkadang menggetarkan. Namun mungkin kamu sudah kecewa dengan kenyataan yang kuungkapkan dalam suratku yang barusan kukirimkan. Mungkin kamu kebingungan dan terpaksa bertanya pada orang yang kebetulan pernah bertemu denganku, entah Mas Herwan FR atau Agus Kresna, meski ada yang merasa tak berhak untuk mengatakan apa-apa karena aku sudah memintanya agar jangan dulu mengabarkan kehadiranku pada orang-orang untuk suatu alasan. Dan rentetan kemungkinan lainnya mengendap dalam benakku. Namun aku harap kamu benar-benar cukup dewasa untuk menerima realita dalam hidup yang penuh ketakterdugaan. Aku kesepian. Apa yang kulakukan. Duduk di kursi sembari mengangkat kaki, dan di rumah hanya ada aku sendiri. Aku membayangkan kamu. Sosok yang tak pernah kutemui. Hanya foto yang kamu kirimkan melengkapi imajinasi: seorang lelaki gondrong yang menarik, dan merasa dirinya secara psikologis sudah dewasa dalam usia 23 tahun. Heran, di luar belasan burung entah apa namanya berseliweran dalam guyuran hujan begini, apa yang mereka cari? Barangkali kamu lebih tahu ekologi dan mau berteori? Aku kedinginan. Aliran listrik padam. Barangkali segelas teh manis panas bisa menghangatkan tubuhku. Apakah di Bandung saat ini sedang hujan juga, dan kamu tengah bagaimana? Mengisap A Mild ditemani secangkir kopi panas? Menulis puisi, cerpen, esai, surat, atau tugas mata kuliah? Di kampus, di rumah, atau di suatu tempat entah? Membaca diktat, buku tertentu, karya sastra, atau komik? Di depan monitor komputer, mengobrol, atau nonton TV? Mendengarkan The Doors atau Ebiet G. Ade? Tidur atau makan? Salat Asar atau menggigil kehujanan? Atau mengguyur badan di kamar mandi? Atau tak melakukan apa-apa sama sekali? Cuma Tuhan yang tahu. Relasi yang aneh, katamu, karena lewat surat. Lalu kamu menyuruhku belajar internet biar bisa bikin e-mail dan tak perlu ke perpustakaan konvensional. Dan kamu janji akan mengajariku jika nanti bertemu. Bertemu. Aku juga ingin bertemu kamu. Namun untuk apa? Adakah makna dari pertemuan itu? Kubayangkan kamu sebagai Indra, temanku, yang membagi dunia lewat tangannya. Namun apa kamu bisa bahasa isyarat sederhana cara abjad? Kamu kecewa karena aku tuli? Apakah dalam surat pertamaku aku harus memberitahu siapa diriku secara mendetail? Aku telah mengambil risiko. Begitu pun kamu. Risiko untuk merelasi diri dan berinteraksi dengan orang asing. Sebuah silaturahmi yang kumulai, haruskah berakhir sia-sia? Aku berusaha menerima diriku sebagaimana adanya dan menjadi orang biasa, meski aku tahu orang-orang di sekitarku kecewa. Keluarga, teman-teman, sahabat dekat, sampai siapa saja yang memang merasa harus kecewa. Bertahun-tahun, ada belasan tahun mungkin, sejak usiaku 16 tahun sampai 25 tahun, kujalani hari dengan sunyi, sebuah dunia tanpa bunyi-bunyi. Bisakah kamu bayangkan? Ah, aku tak akan bisa mendengar permainan harmonikamu, lalu membandingkannya dengan permainan harmonika abangku. Atau denting gitarmu dengan Eric Clapton. Atau bagaimana suatu melodi tercipta dari puisi. Aku juga tak akan tahu warna suaramu saat memusikalisasikan puisi, berdeklamasi, menyanyi, tadarus, berperan dalam lakon teater, atau bicara biasa saja. Kamu masih ingat, dalam salah satu suratmu, kamu menulis: Setting: Kamar, 141000 - 21.20 WIB, Dewa 19 - Terbaik-terbaik. Gurun yang baik. Barangkali sekaranglah saatnya! Lalu kamu membiarkan selembar halaman kertas itu kosong. Aku mengerti artinya, kamu ingin aku memutar lagu tersebut, dan membiarkan Terbaik-terbaik bicara. Sesuatu yang tengah menggambarkan suasana hatimu saat itu? Sayang, aku tak bisa melakukannya. Kata teman-teman, lagu itu tentang cinta dan persahabatan. Kurasa aku harus bertanya pada Rie, Indra, atau Nana; apa ada yang punya teksnya? Ironis, bukan? Tampaknya kamu senang menulis dengan diiringi musik. Aku iri padamu. Karena aku ingin tahu juga seperti apa indahnya musik klasik itu, entah Mozart yang kata Indra melankolis; atau Chopin di masa silam, gumam Cecep Syamsul Hari dalam puisi Meja Kayu yang kembali muram-surealis, menulis lagu pedih tentang hujan2; atau tahu di mana letak jeniusnya Beethoven yang mencipta komposisi meski tuli; dan bisa mengerti mengapa ayahku sangat menyukai musik klasik selain country. Aku rindu bunyi gamelan, dan ingin kembali belajar menari. Entah jaipong Jugala, tari klasik Jawa, atau mungkin sendratari seperti yang sering kusaksikan di TVRI waktu kecil dulu. Aku ingin berperan sebagai Drupadi atau Srikandi, perpaduan antara kelembutan dan keperkasaan. Kamu lebih suka karakter Bima? Aku suka karakter Yudistira, ia satu-satunya yang (hampir) berhasil mencapai puncak Mahameru sementara saudara-saudaranya satu per satu berguguran. Kamu tahu artinya, kan? Aku lupa penggalan kisah ini dari komik wayang R.A. Kosasih atau majalah Ananda -- yang pernah kita baca waktu kanak-kanak dulu, meski mungkin dalam dimensi yang berbeda. Sudahlah, setidaknya aku bisa tahu minatmu, dan kamu tahu minatku. Aku tak tahu banyak tentang musik, padahal kamu pasti asyik sendiri dengan The Corrs, Dewa, Kubik, Jim Morrison, bahkan juga Jimi Hendrix. Mengapa sih dalam cerpenmu yang barusan dimuat koran, kamu menulis soal Jimi Hendrix dan Jim Morrison? Itu mengingatkanku pada Abuy teman SMU-ku yang sangat mengidolakan mereka dan senang cerita soal itu padaku, seolah merekalah yang bisa meluapkan kegelisahan terpendamnya yang liar menuju muara kebebasan. Lucu, adakah orang tuli yang begitu besar rasa ingin tahunya tentang sesuatu yang tak mungkin bisa dirasakan. Katakan aku aneh. Aku memang orang aneh. Namun aku juga berharap bisa tahu lebih banyak tentang Iqbal, Rumi, Camus, Dylan, Gibran, Cummings, Malna, sampai Rendra. Ya, itu jika kita bertemu. Mungkinkah itu? Tempias hujan tidak deras lagi, namun kesedihan itu masih menghantam ruang terdalam. Aku butuh kawan. Kamukah orangnya? Tidak, kamu mungkin sudah berharap agar aku jadi seseorang yang ke lima setelah kamu kecewa dengan sekian perempuan yang masuk dalam hidupmu, meski itu terlalu dini karena kita baru tiga kali saling menyurati. Semudah itukah hatimu terpaut, atau kamu cuma ingin mengujiku? Tidak. Aku tak berharap apa-apa darimu. Aku hanya ingin jadi kawanmu. Kawan biasa. Bukan pacar. Meski aku juga ingin punya pacar, sebagaimana perempuan kebanyakan. Seseorang yang membuatku jatuh cinta sungguhan. Seseorang yang mencintaiku apa adanya. Seseorang di mana bisa berbagi dunia. Naifkah? Hujan. Aku kembali memandang ke luar jendela kaca. Di sana gunung begitu dekat dengan latar pepohonan seperti hamparan permadani hijau kebiruan, dan kabut yang mengental; terasa beku dalam pelukan kegaiban-Nya. Ya Tuhan, barusan kulihat kilatan petir membelah langit desa di sebelah utara. Subhanallah, indah sekali bentuknya; kilatan warna perak yang abstrak dengan latar kelabu. Aku membayangkan bagaimana seandainya jika petir tiba-tiba menghajarku. Sudahlah, mungkin lebih baik aku membayangkan diriku sebagai Walter Spies atau Alain Compost; akan kuabadikan keindahan panorama hujan. Tidak. Aku bukan mereka. Aku cuma punya kata-kata. Bukan kuas atau kamera. Namun kata-kata yang berhamburan dari mulutku pasti tak akan kamu mengerti sepenuhnya jika kita berbicara. Kamu akan membutuhkan waktu untuk mengenali warna suaraku yang kacau intonasinya, seperti teman-teman dekatku. Mungkin cukup lama. Apakah kita akan bertemu dan bicara seolah kawan lama dengan akrabnya? Atau kaku lalu merasa sia-sia? Aku bukan May Ziadah, Elizabeth Whitcomb, Mabel Hubbard-Graham Bell, Marlee Matlin, atau Jane Mawar. Atau perpaduan perempuan mana yang pernah kau kenal.Hujan