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Touch receptors
Sensitive to touch
Pain receptors
Sensitive to pain
Heat receptor
Sensitive to heat
Cold receptors
Sensitive to cold
Pressure receptors
Sensitive to pressure
Epidermis
Dermis
Sweat glandFatty layer
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1. What is meant by the sense of touch?
The ability of the skin to detect stimuli.
2. State five types of receptor which are found in the skin.Pressure, touch, pain, heat and cold.
3. What is the name given to the nerve endings which are sensitive to stimuli?
Receptors.
4. Why are the pain receptors finely branched at their tips near the surface ofthe skin?
So that they can cover a wider area of the skin and detectpain more effectively.
5. What are the advantages of having pain and touch receptors near to thesurface of the skin?
The skin can detect pain and touch more efficiently andquickly.
6. Briefly state what happens when receptors are stimulated.
Nerve endings (receptors) are stimulated and they sendimpulses and information to the brain for processing.
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Part of body Use of toothpicks
One Two
Finger tips
Back of the neck
Lips
Elbow
Knees
Sole of feet
Palm of hands
Back of the ears
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Sensitivity of skin
Parts of body which areless sensitive Elbow
Knees Sole of feet
Palm of hands
Fingertips
Behind the neck Lips Behind the ear
1. State two factors which affect the sensitivity of the skin.
a. Thickness of epidermis
b. Number of receptors
2. Briefly explain your answer in question number 1.The thinner the epidermis, the more sensitive the skin is to
stimuli. The more the number of receptors, the more sensitive
the skin is to stimuli.
3. From the results obtained, classify the sensitivity of skin into two
appropriate groups.
Conclusion
The sensitivity of skin and the body depends on
the thickness of the epidermis and thenum ber of receptors on the particular section of ski
Parts of body which aremore sensitive
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4. Explain why
a. the parts of the body you have stated in (3) are less sensitive to
stimuli.
The epidermis is thick and contains less receptors.
b. the parts of the body you have stated in (3) are more sensitive to
stimuli.
The epidermis is thin and contain more receptors.
5. Why does our skin contain various receptors which are sensitive tostimuli?
So that we can avoided danger.
The sensitivity of skin covering different parts ofthe body varies.
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1. How does a blind man use Braille to read? Which receptors are
functioning when he use Braille to read?A blind person uses touch receptors on thefingertips to read Braille.2. Which receptors are stimulated when we are given an injection?Pain receptors.
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1. On Figure 1, label the parts using the correct words in box.
Heat receptors Touch receptors Cold receptorsPain receptors Pressure receptors Nerves
TouchReceptors
Nerves
Cold receptors
Pressurereceptors
Heat receptors
Pain receptors
Figure 1 Cross-section of the skin
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2. Fill in the blanks with the suitable terms given in the box.
a. The skin is an organ oftouch
b. There are five types of receptors in the skin sensitive tovarious stimuli.
c. The sensitivity of the skin depends on the thickness of theepidermis and the number of receptors on the skin.
d. The thinner the epidermis, the more sensitive it is to stimulus.
e. The more receptors there are on the skin, the more sensitiveit is to stimulus.
f. Blind people use their sense of touch to help them readBraille.
receptors thickness thinner sense of touch touch more number of
