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Coordination in animals
abuse is the excess use of drugs or use for
2. Describe a map of the tongue using
sketched diagram indicating each reasons other than medical. Psychoactive
of the taste areas for each of the drugs are substances that when taken in or
solutions tested in procedure 1-3 administered into one’s system affect the
above. central nervous system. They produce false
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sense of wellbeing and relief from tension,
stress, pain and anxiety. This means the
Exercise 2.4 nervous system of the organism is affected.
1. Explain how is retina adapted to its Categories of drugs
role.
Sedatives
2. Describe the importance of human Are drugs that slow down the functions
skin. of the brain and make a person feel
3. Explain the functions of the taste sleepy. They are used to make someone
buds of the tongue. feel more relaxed. They are also called
depressants. Sedatives include tranquillisers
4. How is the ear adapted to its
functions? and sleeping pills. Tranquillisers, such as
valium (diazepam) and mandrax have
5. What are the functions of the mucus a calming effect and are often given to
found in the nose? people suffering from anxiety. Barbiturates
are among the most powerful relaxant
Drugs and drug abuse and their drugs that are used to provide relief from
effects in nervous coordination depression. Sedatives are known to interfere
Task 2.16 with impulse transmission and with the
Search from reliable internet sources, functioning of the medulla oblongata.
documentary videos showing drugs and Depressants
drug abuse. Watch the videos and prepare
short notes. These are drugs that inhibit the function of
the central nervous system (CNS). They
The brain can be affected by external suppress the part of the brain responsible
influences, particularly drugs. A drug is for sensing pain. They are among the most
any substance natural or synthetic that widely used drugs in the world. These
when taken by man alters the way the drugs operate by affecting neurones in
body works. This can change an organism’s the CNS, which leads to symptoms such
body physiologically or psychologically. as drowsiness, relaxation, decreased
Drugs normally are used for treatment of inhibition, anaesthesia, sleep and even
diseases or for the alleviation of pain. The death. Examples of these drugs includes
use of drugs for unintended purpose or in alcohol, marijuana, heroin, morphine,
excess is called drug abuse. Therefore, drug valium, ether and chloroform. Heroine is
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BIOLOGY FORM 3 FINAL EDITED 16.09.2025.indd 56
BIOLOGY FORM 3 FINAL EDITED 16.09.2025.indd 56 KAMISHNA 23/10/2025 11:52:40
KAMISHNA
