Revision notes Revision notes 溫習筆記

Revision Helper溫習錦囊 (Bilingual version) 雙語版本

Understanding Integrated Science for the 21st Century (3rd Edition) 最新綜合科學 — 邁進 21 世紀 (第三版) © Aristo Educational Press Ltd 2012 © 雅集出版社有限公司 2012

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31.1 The importance of sensing the environment

31.1 探測環境刺激探測環境刺激探測環境刺激探測環境刺激

的重要性的重要性的重要性的重要性

How can we detect different stimuli? 我們如何探測不同的刺激？ Q1

A1

� We can detect different stimuli with five

sense organs: the eyes, ears, nose, tongue

and skin.

� Each kind of sense organ has its own

receptors. When the receptors detect a

stimulus, they send messages to the brain

through nerves to produce senses.

� The following shows the process of how a

sense is produced.

� 我們具有五種感覺器官感覺器官感覺器官感覺器官，包括眼睛、

耳朵、鼻子、舌頭和皮膚，來探測不

同的刺激刺激刺激刺激。

� 每種感覺器官都各有特別的感受器感受器感受器感受器

來探測不同的刺激。當感受器探測到

刺激時，會發出訊息，訊息沿神經神經神經神經傳

送到腦，從而產生感覺感覺感覺感覺。

� 以下顯示感覺產生的過程。

stimulus 刺激

receptors of a sense organ

感覺器官的感受器

brain 腦

sense 感覺

detected by 被探測

send messages through nerve to

把訊息沿神經送到

produces 產生

1 Chapter

Revision notes Air and burning 20

Part

1 第第第第部分部分部分部分 Revision notes 溫習筆記溫習筆記溫習筆記溫習筆記 Chapter

第第第第章章章章 31 Senses and sight 感覺和視覺感覺和視覺感覺和視覺感覺和視覺



2

What kind of stimuli can be detected by

our sense organs and what senses will

be produced?

我們的感覺器官可以探測到哪

些刺激？又會產生哪些感覺？

Q2

A2

� The following table summarises the stimuli

detected by our sense organs and the

corresponding senses produced.

� 下表顯示我們的感覺器官，以及探

測到的刺激和所產生的感覺。

Sense organ 感覺器官感覺器官感覺器官感覺器官 Stimuli detected 探測到的刺激探測到的刺激探測到的刺激探測到的刺激 Sense 感覺感覺感覺感覺

light

光

sight

視覺

sound

聲音

hearing

聽覺

smells of chemical substances

化學物質的氣味

smell

嗅覺

flavours of chemical substances

化學物質的味道

taste

味覺

touch, heat, cold, pressure and pain

觸摸、冷熱、壓力和疼痛

touch

觸覺

eye 眼睛

skin皮膚

ear 耳朵

nose鼻子

tongue舌頭



3

The diagram below shows the structures of the human

eye and their functions.

下圖顯示人眼的結構，眼的各部分

各有不同的功用。

Q3

A3

What are the structures of the human eye?

What is/are the function(s) of each structure?

眼睛是由哪幾部分組成的？

每部分各有甚麼功用？

sclera 鞏膜鞏膜鞏膜鞏膜 � protects the

eyeball � 保護眼球

retina 視網膜視網膜視網膜視網膜 � contains light-

sensitive cells � 滿布感光細胞感光細胞感光細胞感光細胞

blind spot 盲點盲點盲點盲點 � where the optic nerve leaves

the eyeball � 視神經離開眼球的地方 � contains no light-sensitive cells � 不含感光細胞

optic nerve 視神經視神經視神經視神經 � transmits

messages from light-sensitive cells to the brain

� 把感光細胞發出

的訊息傳送到腦

focusing muscle 對焦肌肉對焦肌肉對焦肌肉對焦肌肉 � changes the thickness of the lens � 調節晶狀體的厚度

cornea 角膜角膜角膜角膜 � helps focus light � 有助把光線聚焦

iris 虹膜虹膜虹膜虹膜 � controls the size

of the pupil � 控制瞳孔的大小

pupil 瞳孔瞳孔瞳孔瞳孔 � allows light to

enter the eye � 讓光線從外界進

入眼球內

lens 晶狀體晶狀體晶狀體晶狀體 � helps focus light � 有助把光線聚焦

jelly-like fluid 玻璃狀液玻璃狀液玻璃狀液玻璃狀液 � maintains the shape of

the eyeball � 保持眼球的形狀 � helps focus light � 有助把光線聚焦

31.2 How we see 31.2 我們如何看見東西我們如何看見東西我們如何看見東西我們如何看見東西



4

Q4

A4

How does the eye control the amount of

light entering it?

眼睛如何控制接收的光量？

In dim light, the pupil becomes larger. In bright light, the pupil becomes smaller. 在光線暗淡的環境下，瞳孔擴張。在光線充足的環境下，瞳孔縮小。

� The iris controls the size of the pupil, which in

turn controls the amount of light entering the

eye.

� In dim light, the pupil becomes larger. This

allows more light to enter the eye so that we

can see more clearly.

� In bright light, the pupil becomes smaller to

reduce the amount of light that enters. This

prevents strong light from damaging the eye.

� 眼球內的虹膜控制瞳孔的大小，從而

控制進入眼睛的光量。

� 在光線暗淡的環境下，瞳孔擴張，讓

更多光線進入眼睛，使我們可以清楚

地看見東西。

� 在光線充足的環境下，瞳孔縮小，減

少進入眼睛的光量，避免強光損害我

們的眼睛。



5

The diagram below shows how an image of an

object is formed in the eye.

下圖顯示物件的影像如何在眼睛內形成。

A5

Q5 How is an image of an object

formed in the eye?

物件的影像如何在眼睛內形成？

The cornea, the lens and the jelly-like fluid help focus the light onto the retina. 角膜、晶狀體和玻璃狀液把光

線聚焦。 Light from an object (i.e. the candle) enters the eye. 來自物體 (例如：蠟

燭) 的光線進入眼睛。

A sharp and inverted image is formed on the retina. The light-sensitive cells on the retina are stimulated to produce messages. 視網膜上形成一個清晰倒置

的影像。視網膜上的感光細

胞受刺激後發出訊息。

Messages from the light-sensitive cells are sent through the optic nerve to the brain. 訊息沿視神經傳送到腦。

2

1

4

3

lens 晶狀體

jelly-like fluid玻璃狀液

pupil 瞳孔

retina 視網膜

cornea

角膜

to the brain 往腦部

optic nerve視神經



6

� When we look at near objects, the focusing

muscles contract and the lens becomes thicker

� 當我們觀看近處的物體時，對焦

肌肉收縮，晶狀體變厚。

� When we look at distant objects, the focusing

muscles relax and the lens becomes thinner.

� 當我們觀看遠處的物體時，對焦

肌肉鬆弛，晶狀體變薄

A6

How do the focusing muscles and the

lens change when we see things at

different distances?

當我們觀看不同距離的物

體時，對焦肌肉和晶狀體

會如何改變？

Q6

light from a near object 來自近處物體的光線

focusing muscle contracts對焦肌肉收縮

near object近處物體

lens becomes thicker 晶狀體變厚

light from a distant object 來自遠處物體的光線

focusing muscle relaxes 對焦肌肉鬆弛

lens becomes thinner 晶狀體變薄



7

� Cone cells and rod cells are two kinds of

light-sensitive cells on the retina.

� The following table shows the differences

between cone cells and rod cells.

� 視網膜上有兩種感光細胞，分別是

視錐細胞視錐細胞視錐細胞視錐細胞和視桿細胞視桿細胞視桿細胞視桿細胞。

� 下表顯示視錐細胞和視桿細胞的

分別。

Cone cells 視錐細胞視錐細胞視錐細胞視錐細胞 Rod cells 視桿細胞視桿細胞視桿細胞視桿細胞

� three types, sensitive to red, green and

blue light

� 有三種，分別對紅光、綠光和藍光敏感

� one type only

� 只有一種

� responsible for colour vision

� 負責色覺

� responsible for black and white vision

� 負責黑白視覺

� work well in bright light

� 在光線充足的環境下運作最佳

� important for vision in dim light

� 在昏暗的環環境下運作最佳

A7

What are the light-sensitive cells on

the retina?

視網膜上有哪些感光細胞？

Q7



8

Yes, there are some limitations of our eyes. We cannot

see objects that are too small, too close or too far away.

我們的視覺是有限制的，我們不能

清楚看見太小、太近或太遠的物體。

Are there any limitations of our eyes? 我們的視覺是否有限制？ Q8

A8

31.3 Limitations of our eyes 31.3 視覺上的限制視覺上的限制視覺上的限制視覺上的限制

� Scientists have invented a variety of optical

instruments to help extend our vision.

� The following optical instruments can help us

see objects that are too small.

� 科學家發明了多種光學儀器光學儀器光學儀器光學儀器，來幫助人

類克服視覺上的限制，擴闊視野。

� 以下的光學儀器，有助我們觀察體積很

小的物體。

hand lens 放大鏡

light microscope 光學顯微鏡

electron microscope 電子顯微鏡

� The following optical instruments can help us

see objects that are too far away.

� 以下的光學儀器，有助我們觀察距離很

遠的物體。

binoculars 雙筒望遠鏡

astronomical telescope 天文望遠鏡

How can we extend our vision? 我們如何克服視覺上的限制，擴闊視野？

Q9

A9



9

� The eye has a blind spot on the retina where

the optic nerve leaves the eyeball.

� There are no light-sensitive cells on the blind

spot. When light falls on the blind spot, no

message is sent to the brain. Therefore we

cannot see the images formed on the blind spot.

� 眼球內的視網膜上有一個盲點盲點盲點盲點，是

視神經離開眼球的地方。

� 盲點是視網膜上一處沒有感光細胞

的地方。一旦光線落在盲點上，由

於沒有感光細胞探測光，也就沒有

訊息發出傳送到腦，因此我們無法

看見在盲點上形成的影像。

What is blind spot? What happens

when light falls on the blind spot?

甚麼是盲點？當光線落在

盲點上，會有甚麼發生？

blind spot盲點

A10

Q10

Blind spot on the retina視網膜上的盲點



10

31.4 Eye defects and eye care

31.4 眼睛毛病和眼睛眼睛毛病和眼睛眼睛毛病和眼睛眼睛毛病和眼睛

的保護的保護的保護的保護

Short sight, long sight, cataract, astigmatism and

colour blindness are some common eye defects.

近視近視近視近視、遠視遠視遠視遠視、白內障白內障白內障白內障、散光散光散光散光和色盲色盲色盲色盲

是最常見的眼睛毛病。

1. Short sight 1. 近視

� People with short sight cannot see distant

objects clearly because the images of the

distant objects are formed in front of the retina.

� Short sight may be caused by the lens being

too thick or the eyeball being too long, or both.

� Short sight can be corrected by wearing

glasses with concave lenses.

� 患有近視的人不能夠清楚看見遠處的

物體，原因是遠處物體的影像會在視網

膜的前方形成。

� 近視是由於晶狀體過厚或眼球過長，又

或是兩種情況同時出現所引致的。

� 佩戴以凹透鏡凹透鏡凹透鏡凹透鏡製成的眼鏡可矯正近視。

Short sight 近視 Correction of short sight 近視的矯正方法

A11

Suggest some examples of common

eye defects. How can we correct

these eye defects?

常見的眼睛毛病有哪幾種？

我們如何矯正這些眼睛毛病？

Q11

sharp image formed on the retina 清晰影像在視

網膜上形成


image is formed in front of the retina 影像在視網膜的前方形成

concave lens 凹透鏡




11

2. Long sight 2. 遠視

� People with long sight cannot see near

objects clearly because the images of the

near objects are formed behind the retina.

� Long sight may be caused by the lens being

too thin or the eyeball being too short, or both.

� Long sight can be corrected by wearing

glasses with convex lenses.

� 患有遠視的人不能夠清楚看見近處的

物體，原因是近處物體的影像會在視網

膜的後方形成。

� 遠視是由於晶狀體過薄或眼球過短，又

或是兩種情況同時出現所引致的。

� 佩戴以凸透鏡凸透鏡凸透鏡凸透鏡製成的眼鏡可矯正遠視。

Long sight 遠視 Correction of long sight 遠視的矯正方法

3. Cataract 3. 白內障

� People with cataracts have cloudy lens. They will

slowly develop blurred vision, and may even

become blind.

� Most cases of cataracts are related to ageing.

Cataracts can also be caused by other factors

such as diabetes, eye injuries, prolonged exposure

to sunlight and heredity.

� To cure a cataract, the lens can be replaced with

an artificial one through surgery.

� 白內障患者的晶狀體會變得混

濁，所見的影像會變得模糊，情況

嚴重的甚至可以失明。

� 白內障在老年人十分常見，此外糖

尿病、眼睛創傷、長期受陽光照射

及遺傳等因素都會增加患白內障

的風險。

� 治療白內障的方法是透過手術，把

混濁的晶狀體換上人工晶狀體。

A11

light from a near object來自近處物體的光線

light from a near object 來自近處物體的光線

A cataract is an eye defect in which the lens becomes cloudy. 白內障患者的晶狀體變得混濁。

Image would be formed behind the retina 影像在視網膜的

後方形成

sharp image formed on the retina 清晰影像在視

網膜上形成 convex lens

凸透鏡



12

4. Astigmatism 4. 散光

� Astigmatism is caused by the cornea or lens (or

both) being unevenly curved. The light from an

object cannot be focused onto the retina as a

sharp image.

� Astigmatism can be corrected by wearing glasses

with specially made lenses.

� 散光的成因是角膜或晶狀體的弧

度不均勻，使光線不能聚焦在視

網膜上形成清晰的影像。

� 佩戴用特別透鏡製成的眼鏡可矯

正散光。

5. Colour blindness 5. 色盲

� Some people with colour blindness cannot

distinguish between certain or all colours.

� Colour blindness is caused by the absence or

defect of one or more types of cone cells on the

retina.

� The most common form of colour blindness is

red-green colour blindness. People with

red-green colour blindness find it difficult to

distinguish between red and green.

� Colour blindness is an inherited defect and it is

more commonly found in males. It cannot be

corrected.

� 患有色盲的人不能分辨某些或全

部顏色。

� 色盲的成因是視網膜上其中一種

或多種視錐細胞的數目不足或不

能正常運作。

� 最常見的色盲是紅綠色盲，患者

不能分辨紅色和綠色。

� 色盲是遺傳的，男性患者較女性

為多。目前還未有方法可以矯正

色盲。

A11



13

The following are some tips on how we can take care

of our eyes.

以下是一些保護眼睛的方法。

Read under sufficient but not strong light. Keep a distance of about 30 cm between your eyes and the book. 在光線充足 (但並非強光) 的環

境下閱讀；書本與眼睛應保持 30 cm 距離。

Keep a distance of 50 – 70 cm between your eyes and the monitor when using the computer. 使用電腦時，眼睛與屏幕應保持 50 至 70 cm 距離。

After reading a book or using a computer for 30 minutes, take a break and look at distant objects. 閱讀或使用電腦每 30 分鐘，應

讓眼睛休息數分鐘；休息時望

向遠處。

Always wear safety goggles whenever there is a risk to the eyes during experiments. 進行實驗時，如有需要應佩戴安

全眼鏡。

Have regular eye check-ups every year and correct eye defects as soon as possible. 每年定期接受眼睛檢查，若眼睛

出現毛病，便應及早矯正。

Do not rub your eyes to avoid infection. 不要用手揉擦眼睛，避免受到

細菌感染。

A12

How can we take care of our eyes? 我們應如何保護眼睛？ Q12

�

50 − 70 cm

30 cm



14

How is sound produced and transmitted

to our ears?

聲音是如何產生和傳送的？

Q13

A13

� Sound is produced by vibrations of objects.

� When an object vibrates, it causes the

surrounding air particles to vibrate. The

vibrations of air particles travel through air.

When the vibrations reach our ears, we hear the

sound.

� 聲音是由物體的振動振動振動振動而產生的。

� 當物體振動時，會使四周的空氣粒

子亦振動起來，空氣粒子的振動逐

漸向四周傳送開去。當空氣粒子的

振動傳到我們的耳朵時，我們便能

聽到聲音。

� Sound must travel through a medium (e.g. a

gas, a liquid or a solid). It cannot travel through

a vacuum.

� 聲音必須透過介質介質介質介質來傳送，介質

可以是固體、液體和氣體。然而，

聲音不能夠在真空中傳送。

vibrations of air particles空氣粒子的振動

32.1 Sound 32.1 聲音聲音聲音聲音

32 Hearing 聽覺聽覺聽覺聽覺

Chapter 第第第第章章章章



15

What are the main parts of the ear

and their functions?

耳朵是由哪些部分組成的？每部

分各有甚麼功能？ Q14

A14

� The ear is divided into three parts: the outer

ear, the middle ear and the inner ear.

� The diagram below shows the structure of the

human ear and their functions.

� 耳朵可分為三部分，分別是外耳外耳外耳外耳、中中中中

耳耳耳耳和內耳內耳內耳內耳。

� 下圖顯示耳朵各主要部分及其功能。

pinna 耳殼耳殼耳殼耳殼 � collects sound in the

surroundings and directs the sound along the ear canal to the eardrum

� 收集環境中的聲音，

聲音沿聽道傳送到耳

auditory nerve 聽神經聽神經聽神經聽神經 � transmits

messages to the brain

� 傳送訊息到腦部

outer ear middle ear inner ear 外耳中耳內耳

ear canal 聽道聽道聽道聽道

eardrum 耳膜耳膜耳膜耳膜

ear bones 聽骨聽骨聽骨聽骨 � magnify the vibrations of

the eardrum and transmit them to the inner ear

� 把耳膜傳來的振動放大並傳

送到內耳

cochlea 耳蝸耳蝸耳蝸耳蝸 � contains receptors that are

stimulated by the vibrations to send out messages

� 從中耳傳來的振動能刺激耳

蝸內的感受器發出訊息

32.2 How we hear 32.2 我們如何聽到聲音我們如何聽到聲音我們如何聽到聲音我們如何聽到聲音



16

How do our ears detect sound?

我們的耳朵是如何運作使我們可以

聽到聲音？ Q15

A15

The diagram below shows the process of how our ears

detect sound.

下圖顯示聽覺產生的過程。

Sound in the surroundings is collected by the pinna. 耳殼收集環境中的聲音。

The sound travels along the ear canal to the eardrum 聲音沿聽道傳送到耳膜。

2 The sound causes the eardrum to vibrate. 聲音使耳膜振動。

3

The ear bones magnify the vibrations of the eardrum and transmit them to the inner ear. 聽骨把耳膜傳來的振動放

大並傳送到內耳。

The vibrations stimulate the receptors in the cochlea to send out messages. 振動會刺激耳蝸內的

感受器發出訊息。

5 The messages are sent along the auditory nerve to the brain. The brain then interprets the messages as sound. 訊息沿聽神經傳送到腦，腦

把訊息詮釋，產生聽覺。

6

1

4



17

What is the frequency of sound?

甚麼是聲音的頻率？

Q16

A16

� Sound is produced by vibrations of objects.

� The number of vibrations per second is called

frequency.

� The unit of frequency is hertz (Hz).

� The faster the object vibrates, the higher the

frequency of the sound it produces.

� 物體振動會產生聲音。

� 物體每秒振動的次數稱為頻率頻率頻率頻率。

� 頻率的單位是赫茲赫茲赫茲赫茲 (Hz)。

� 物體振動得愈快，所產生的聲音

的頻率便愈高。

32.3 Limitations of our ears 32.3 聽覺上的限制聽覺上的限制聽覺上的限制聽覺上的限制

Are there any limitations to our ears?

我們的聽覺是否有限制的？

Q17

A17

� Yes, there are limitations to our ears. We can

only hear sounds within a certain range of

frequencies.

� We can hear the sound of frequencies from

about 20 Hz to 20,000 Hz. This range of

frequencies is called the audible frequency

range. It varies from person to person.

� 我們的聽覺是有限制的，只能聽到特

定頻率範圍內的聲音。

� 我們的耳朵能夠聽到介乎 20 Hz 至

20,000 Hz 頻率範圍以內的聲音，這

個頻率範圍稱為聽頻範圍聽頻範圍聽頻範圍聽頻範圍。每個人的

聽頻範圍都有所差異。



18

32.4 Noise pollution 32.4 噪音噪音噪音噪音

What is noise? Suggest some examples of

common sources of noise in Hong Kong.

甚麼是噪音？香港的噪音

有哪些來源？

Q18

A18

� Noise is any sound that is unwanted, disturbing,

or so loud that it can cause damage to our ears.

� The following are some common sources of

noise in Hong Kong.

� 噪音噪音噪音噪音是指一些使人煩燥、造成滋

擾，甚至損害聽覺的聲音。

� 以下是香港的噪音的主要來源。

Cars 車輛 Airplane 飛機

Construction work 建築工程 Machinery 機械運作



19

How can we measure the loudness of a sound? 如何量度音量？ Q19

A19

� The loudness of a sound is indicated by its

sound level.

� A decibel meter can be used to measure sound

levels.

� The unit of sound level is decibel (dB).

� 聲音的水平可用音量來表示。

� 我們可以用分貝計分貝計分貝計分貝計來量度音量。

� 音量的單位是分貝分貝分貝分貝 (dB)。

A decibel meter 分貝計

How does noise affect us? How can we

protect our ears?

噪音對我們有甚麼影響？

我們如何保護聽覺？

Q20

A20

� Long-term exposure to noise may cause

mental stress and hearing loss.

� The following shows some ways of protecting

our ears.

� 長期處於噪音環境會導致精神緊張

及聽覺受損。

� 以下是一些保護聽覺的方法。

� Avoid staying too long in noisy places, such

as karaoke bars and construction sites.

� Keep the volume low when listening to

music, especially when using earphones.

� Wear ear protectors when working in a

noisy environment.

� Do not pick your ears with hard objects.

� 避免長時間逗留在嘈吵的地方，

例如卡拉 OK 場所和建築工地。

� 聽音樂時，尤其是使用耳筒時切

勿把音量調得過高。

� 在噪音環境中工作時，應戴上聽

覺保護器。

� 不要用硬物挖耳朵。



20

What measures has the Hong Kong

government taken to control noise pollution?

香港政府推出了哪些管制

噪音的措施？

Q21

A21

The Hong Kong government has taken measures to

control noise pollution. The following are some of these

measures.

香港政府推出了一連串管制噪音

的措施，以下是其中一些例子。

Reduce the production of noise 減少產生噪音

� Cover road surfaces with special

materials to reduce traffic noise.

� 在馬路表面鋪上吸音物料，以減少馬路

與汽車輪胎摩擦時所產生的噪音。

� Limit the time for noisy construction

works to daytime hours on weekdays.

� 限制建築工程只可在星期一至五的日

間時段內進行。

� Impose penalties on people who disturb

neighbours by making noise at night.

� 任何人不得在晚上製造聲浪滋擾鄰

居，否則會被檢控。

Prevent the transmission of noise 阻擋噪音傳送

� Protect residential areas from traffic

noise by building noise barriers along

busy roads and railways.

� 在鄰近住宅區的高速公路或鐵路旁加

建隔音屏障或隔音罩，以減少噪音對居

民的影響。

� Provide schools with special windows

and air conditioning to reduce the noise

from nearby road traffic.

� 資助受噪音滋擾的學校安裝隔音窗戶

和冷氣機，以提供較寧靜的上課環境。



21

What is the sense organ of touch,

heat, cold, pressure and pain?

甚麼感覺器官負責探測觸

摸、冷熱、壓力和疼痛？

Q22

A22

� Skin is the sense organ of touch, heat, cold,

pressure and pain.

� In the skin, there are different kinds of

receptors that can detect touch, heat, cold,

pressure and pain.

� When these receptors are stimulated, they

send messages to the brain through nerves.

The brain then interprets the messages and

produces the sensations we experience.

� 皮膚是負責探測觸摸、冷熱、壓力和

疼痛的感覺器官。

� 皮膚內有很多不同種類的感受器，分

別能探測觸摸、冷熱、壓力和疼痛。

� 當這些感受器受到刺激後，會發出訊

息，訊息沿神經傳送到腦。腦詮釋這

些訊息，產生相應的感覺。

temperature receptor 溫度感受器

touch receptor 觸覺感受器

pressure receptor 壓力感受器

pain receptor痛覺感受器

Different kinds of receptors in the skin 皮膚內不同種類的感受器

33.1 Sense of touch 33.1 觸覺觸覺觸覺觸覺

Senses of touch, smell and taste 觸覺觸覺觸覺觸覺、、、、嗅覺和味覺嗅覺和味覺嗅覺和味覺嗅覺和味覺

Chapter 第第第第章章章章 33



22

Are different parts of the skin equally

sensitive to touch?

皮膚不同部位對觸覺的敏感度

是否相同？

Q23

A23

� The skin of different parts of the body has a

different sensitivity to touch because the touch

receptors are not evenly distributed in the skin.

� Some parts of our body such as the elbows have

fewer touch receptors. They are less sensitive to

touch. Our fingertips have a lot of touch receptors.

They are highly sensitive to touch.

� 皮膚內的觸覺感受器的分布並

不平均，因此身體不同部位的皮

膚對觸覺的敏感度並不相同。

� 身體某些部分，例如手肘的觸覺

感受器較少，因此對觸覺不大敏

感。而指尖則有大量觸覺感受

器，因此對觸覺較為敏感。

Is our skin reliable in detecting heat and cold? 以皮膚探測冷熱可靠嗎？

Q24

A24

No, our skin is not reliable in detecting hot and cold. 以皮膚來探測冷熱並不可靠。



23

What is the sense organ for smell?

How do we detect smell?

甚麼感覺器官負責嗅覺？我們

如何探測氣味？

Q25

A25

� The nose is the sense organ for smell. There are

smell receptors in our nose for detecting smell.

� When these receptors are stimulated by

chemicals in the air we breathe in, they send

messages to the brain through nerves. The

brain interprets the messages as smell.

� The figure below show how we detect smell.

� 鼻子是負責嗅覺的感覺器官。我們

的鼻腔內有數百萬個嗅覺感受器嗅覺感受器嗅覺感受器嗅覺感受器。

� 當嗅覺感受器受到空氣中的化學物

質刺激後，便會發出訊息，訊息沿

神經傳送到腦，腦把訊息詮釋，產

生嗅覺。

� 下圖顯示我們如何探測氣味。

Chemicals from the food spread in the air. 食物的化學物質擴散到

空氣中。

When we breathe in, the chemicals enter our nose and dissolve in the mucus in the nasal cavity. 吸氣時，這些化學物質被

吸進鼻腔內，並溶於鼻腔

內的黏液中。

2

1

The dissolved chemicals stimulate the smell receptors to produce messages. 溶解了的化學物質刺激

嗅覺感受器產生訊息。

3 The messages are sent through the nerve to the brain where they are interpreted as smell. 訊息沿神經傳送到腦，腦

把訊息詮釋為氣味。

4

mucus黏液

smell receptors 嗅覺感受器

nerve神經

33.2 Smell and taste 33.2 嗅覺和味覺嗅覺和味覺嗅覺和味覺嗅覺和味覺



24

What is the sense organ for taste?

How do we detect taste?

甚麼感覺器官負責味覺？

我們如何嚐到味道？

Q26

A26

� The tongue is the sense organ for taste. On the

tongue, there are taste buds, each of which

contains a group of taste receptors.

� When these receptors are stimulated by

flavouring chemicals in food or drink, they send

out messages to the brain through nerves. The

brain interprets the messages as taste.

� There are four types of taste receptors in the

taste buds. Each type detects one of the four

primary tastes: sweet, sour, salty and bitter.

� The figure below shows the process of how the

sense of taste is produced.

� 舌頭是負責味覺的感覺器官。舌頭

上有多個味蕾味蕾味蕾味蕾，每個味蕾內有很多

味覺感受器味覺感受器味覺感受器味覺感受器。

� 當味覺感受器受到食物或飲品中

的化學物質刺激時，會發出訊息，

訊息沿神經傳送到腦，腦把訊息詮

釋，產生味覺。

� 味蕾上有四種味覺感受器，分別探

測甜、鹹、苦和酸四種基本味道。

� 下圖顯示味覺產生的過程。

Chemicals in food dissolve in the saliva. 食物中的化學物質溶於唾液中。

The dissolved chemicals stimulate taste receptors to produce messages. 溶解了的化學物質刺激味覺感

受器發出訊息。

The messages are sent through nerves to the brain where they are interpreted as taste. 訊息沿神經傳送到腦，腦把訊息

詮釋為味道。

1

2

3

taste bud味蕾

taste receptor 味覺感受器

chemical in food 食物中的

化學物質

to the brain 訊息傳送到腦

1

2

3



25

What is the relationship between our senses

of smell and taste?

嗅覺和味覺有甚麼關係？ Q27

A27

Our sense of smell affects our sense of taste. They

work together to detect the flavour of food.

我們同時用嗅覺和味覺來探測食物的

味道，鼻子所探測到的氣味會影響舌

頭所探測到的食物味道。



26

34.1 Understanding the brain 34.1 認識腦部認識腦部認識腦部認識腦部

What is the role of the brain in

sensing the environment?

腦在察覺環境中的角色是怎樣的？

Q28

A28

� The brain receives messages from the sense

organs. After interpreting the messages, it sends

messages to the muscles to make responses.

� The figure below shows the process of detecting

stimuli and making responses.

� 腦接收從感覺器官傳來的訊息，把

訊息加以分析，產生感覺，然後作

出決定，發出訊息到肌肉，使肌肉

作出反應反應反應反應。

� 下圖顯示探測刺激和作出反應的

過程。

stimulus 刺激刺激刺激刺激 sense organ 感覺器官感覺器官感覺器官感覺器官 brain 腦腦腦腦

The alarm clock rings. 鬧鐘響起。

Ears detect the sound of the alarm and send messages to the brain. 耳朵探測到鬧鐘的聲響，並

發出訊息傳送到腦。

The brain interprets the messages, produces the sensation and decides what to do. 腦分析來自感覺器官的訊息，產生感覺，並作出決定。

muscles 肌肉肌肉肌肉肌肉 response 反應反應反應反應

The brain sends messages to the muscles. 腦發出訊息到肌肉。

The muscles make a response: getting up to turn off the alarm. 肌肉作出反應：起床並關掉鬧鐘。

1 2 3

4 5

The brain and our senses 腦和我們的感覺腦和我們的感覺腦和我們的感覺腦和我們的感覺

Chapter 第第第第章章章章 34



27

What are the main parts of the brain and

their functions?

腦主要由哪幾部分組成？

每部分各有甚麼功能？

Q29

A29

� The brain is made up of three main parts: the

cerebrum, the cerebellum and the medulla.

� The figure below shows the main parts of the

brain and their functions:

� 腦由大腦大腦大腦大腦、小腦小腦小腦小腦和延延延延髓髓髓髓三個主要部

分組成。

� 下圖顯示腦的主要部分及每部分的

功能。

medulla 延髓延髓延髓延髓 � controls heartbeat,

breathing and blood pressure, etc.

� 控制心跳、呼吸和保

持血壓等

cerebrum 大腦大腦大腦大腦 � interprets the messages

from sense organs � 分析來自感覺器官的訊息 � sends messages to the

muscles to make response � 發出訊息到肌肉以作出反應 � responsible for intelligence,

memory and thinking � 負責智力、記憶和思考

cerebellum 小腦小腦小腦小腦 � coordinates muscles to

produce body movement � 協調肌肉、控制身體運動 � maintains the balance of the

body � 保持身體平衡

What is reaction time? Can it be

improved by training?

甚麼是反應時間？反應時間

可否透過訓練而縮短？

Q30

A30

� Reaction time is the time between detecting

a stimulus and making a response. It varies

from person to person.

� Reaction time can be improved by training.

� 反應時間反應時間反應時間反應時間是指身體由探測到刺激到

作出反應所需的時間。反應時間的

長短因人而異。

� 反應時間可以透過訓練而縮短。



28

What is a breathalyser?

甚麼是酒精測試機？

Q33

A33

� The breathalyser is a device for measuring

the amount of alcohol in one’s breath.

� It contains acidified dichromate solution. If

one’s breath contains alcohol, the acidified

dichromate solution reacts with the alcohol

and turns from orange to green.

� The higher the content of alcohol in one’s

breath, the greener the solution.

� 用來量度酒精含量的儀器稱為酒精測酒精測酒精測酒精測

試機試機試機試機。

� 酒精測試機內含有已酸化的重鉻酸鹽

溶液，當測試者呼出的空氣中含有酒

精時，已酸化的重鉻酸鹽溶液會與酒

精反應，並由橙色變為綠色。

� 測試者呼出的空氣中酒精含量愈高，

溶液所呈現的綠色便會愈深。

A driver being tested with a breathalyser 警員利用酒精測試機為駕駛者進行呼氣測試

34.2 Effects of alcohol, drugs and solvents on our senses

34.2 酒精酒精酒精酒精、、、、藥物藥物藥物藥物、、、、毒品和溶毒品和溶毒品和溶毒品和溶

劑對我們感覺的影響劑對我們感覺的影響劑對我們感覺的影響劑對我們感覺的影響

What are illusions?

甚麼是錯覺？

Q31

A31 When the brain interprets messages

incorrectly, illusions may result.

腦有時會錯誤分析訊息，產生

錯覺錯覺錯覺錯覺。

What are the effects of alcohol on us? 酒精對人體有甚麼影響？

Q32

A32

� Alcohol slows down our responses to stimuli (i.e.

increasing the reaction time) and affects our

judgement of speed and distance.

� It can affect our body coordination, sight and

hearing, speech, etc.

� Drinking too much alcohol in the long term can

damage the brain and the liver seriously.

� 酒精會使人反應遲緩 (即延長反

應時間) 和影響我們判斷速度和

距離的能力。

� 酒精亦會影響身體協調能力、視覺

和聽覺、說話能力等。

� 長期過量地飲酒會嚴重傷害腦和

肝臟。



29

What are the effects of drug abuse? 吸食毒品會對人體構成甚麼影響？

Q34

A34

� Drug abuse brings harmful effects on the

nervous system, particularly the brain.

� It can slow down a person’s reaction, affect

his/her judgement and cause illusions.

� It can also affect the mood and behaviour of a

person. When a person abuses drugs, he/she

may feel angry, anxious or depressed.

� 吸食毒品會損害我們的神經系統，包

括腦部。

� 吸食毒品會使人反應遲緩和判斷能力

下降，產生錯覺。

� 吸食毒品亦會影響人的情緒和行為，

吸毒者會感到憤怒、焦慮或抑鬱。

What are the effects of solvents on us? 嗅溶劑會對人體造成甚麼影響？

Q35

A35

� Sniffing organic solvents (e.g. thinner)

damages the nervous system and can lead

to addiction.

� Exposure to these solvents will irritate the

eyes and the respiratory system.

� When sniffed, the chemicals get into the

blood through the lungs quickly and may

lead to the following:

� 嗅有機溶劑 (例如：天拿水天拿水天拿水天拿水) 會對神

經系統造成影響，令人上癮。

� 有機溶劑揮發出來的氣體會刺激眼睛

和呼吸道系統。

� 當人吸入這些氣體時，氣體會迅速地

經肺部進入血液中，並可能會引致以

下後果：

� loss of judgement and muscle control

� damage to the lungs and the brain

� death

� 失去判決能力和控制肌肉的能力

� 損害肺和腦

� 死亡



30

A. True or false questions 是非題是非題是非題是非題

Write ‘T’ for a true statement or ‘F’ for a false statement in each box provided. 細閱以下句子，正確的在方格內填上「T」，不正確的則填上「F」。

1. The receptors in the ears can detect sound only. □

2. The cornea is colourless and helps focus light. □

3. There are some light-sensitive cells on the blind spot. □

4. Sound cannot travel through a vacuum. □

5. Frequency is the number of vibrations of an object per minute. □

6. The four primary tastes are sweet, sour, salty and bitter. □

7. Reaction time is the same for everyone. □

8. Alcohol and drug abuse causes addiction. □

B. Multiple-choice questions 多項選擇題多項選擇題多項選擇題多項選擇題

Choose the correct answer for each of the following questions. 選出正確的答案，然後在空格內填上代表該答案的英文字母 1. Which of the following are sense organs?

(I) Eye

(II) Hair

(III) Nose

A. (I) and (II) only

B. (I) and (III) only

C. (II) and (III) only

D. (I), (II) and (III) □

2. Which of the following structures of our eyes has colour?

A. Cornea

B. Iris

C. Lens

D. Jelly-like fluid □

3. Which of the following eye defects CANNOT be corrected?

A. Short sight

B. Cataract

C. Astigmatism

D. Colour blindness □

Part

2 第第第第部分部分部分部分 Revision exercise 單元練習單元練習單元練習單元練習



31

4. Which of the following media can sound travel through?

(I) Air

(II) Wood

(III) Water





5. Which of the following stimuli can be detected by skin?

(I) Touch

(II) Pressure

(III) Pain





6. Which of the following statements concerning our tongue are correct?

(I) It is the sense organ for taste.

(II) There are five types of taste receptors in the taste buds on the tongue.

(III) The smell detected by our nose will affect the taste detected by our tongue.





7. Which of the following is NOT the function of cerebrum?

A. It controls heartbeat, breathing and blood pressure.

B. It is responsible for intelligence, memory and thinking.

C. It sends messages to the muscles to make responses.

D. It interprets the messages from sense organs. □



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8. Which of the following statements concerning a breathalyser are correct?

(I) It contains acidified dichromate solution that can react with alcohol and turns from

green to orange.

(II) It is a device for measuring the amount of alcohol in one’s breath.

(III) The degree of the colour of the solution can indicate the amount of alcohol in one’s body.





C. Short questions 短問題短問題短問題短問題

1. The diagram below shows the structures of the human eye.

(a) Identify the labelled parts of the human eye and state their corresponding functions.

____________________________________________________________________

____________________________________________________________________ (b) When a person looks at distant objects, how will A and C change?

____________________________________________________________________ (c) When a person enters a dark room, how will B change?

____________________________________________________________________ (d) (i) If a person has long sight, what problem does he have in seeing?

________________________________________________________________

(ii) How can long sight be corrected?

________________________________________________________________

A

B

C



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2. The diagram below shows the structures of the human ear.

(a) Identify the labelled parts of the human ear.

____________________________________________________________________

____________________________________________________________________ (b) What happens to B when the sound reaches it?

____________________________________________________________________ (c) Suggest two ways for protecting our ears.

____________________________________________________________________

____________________________________________________________________

A

B C



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Answers 答案答案答案答案

A. True or false questions 是非題是非題是非題是非題

1. T

2. T

3. F

4. T

5. F

6. T

7. F

8. T

B. Multiple-choice questions 多項選擇題多項選擇題多項選擇題多項選擇題

1. B

2. B

3. D

4. D

5. D

6. B

7. A

8. C

C. Short questions 短問題短問題短問題短問題

1. (a) A is focusing muscle. It changes the thickness of the lens.

B is pupil. It allows light to enter the eye.

C is lens. It helps focus light.

(b) A (the focusing muscle) relaxes and C (the lens) becomes thinner.

(c) B (the pupil) becomes larger.

(d) (i) He cannot see near objects clearly.

(ii) Long sight can be corrected by wearing glasses with convex lenses.

2. (a) A is pinna. B is eardrum. C is cochlea.

(b) B (the eardrum) vibrates.

(c) Avoid staying too long in noisy places, such as karaoke bars and construction sites.

Do not pick your ears with hard objects.

(or any other reasonable answers)

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