2.11.3 Hormonal Coordination in the Body (Structured Questions)

Question 1:
Diagram 1 shows the location of endocrine glands of a woman.
(a) Name glands R and S in the boxes provided in Diagram 1.

(b) State one function of hormone secreted by glands R and S.

(c) State one effect to the woman if both glands S are removed.

(d) Label with letter X the thyroid gland in Diagram 1.

R: Pituitary gland
S: Ovary

R: Simulates the production of hormone by thyroid gland
S: Control menstrual cycle



2.11.2 The Human Brain (Structured Questions)

Question 1:
Diagram below shows the structure of a human brain.

(a) Name the parts A and B in the boxes provided in the diagram using the following terms:

(b) State one function of B.

(c) What will happen to a person if area D is injured? What is the effect on man if part D is injured?

(d) Part C controls involuntary action.
Mark (\/) the action which is controlled by part C.


(b) Maintains balance and body posture

(c) Loss of memory


Question 2:
Diagram 1 shows the part of the human brain.

(a) Based on Diagram 1, name parts W and Y in the boxes provided using the following information.

(b) State the function of W and Y.
W: _____________________
Y:  _____________________

(c) What will happen to a person if area X is injured?

(d) In diagram 2, label Q to show the area that controls hearing.


(b) W: Control voluntary actions
   Y: Control involuntary actions

(c) The person will lose control of his muscular coordination and balance.


2.11.1 Human Nervous System (Structured Questions)

Question 1:
Diagram 1 shows the structure of a neurone.

(a) Based on the diagram, mark (\/) the type of neurone in the box provided.

(b)(i) Name P.

(b)(ii) State two functions of P.

(c) Name Q.

(d) Diagram 2 shows the pathway of an impulse.

Mark (\/) the location of neurone in Diagram 2.



1. Receives impulse from other neurones.
2. Transmits impulses to the cell body via the dendron.

Effector or muscle fibres


Question 2:
Diagram 1 shows two types of neurones.

(a) Name the type of neurone shown in Diagram 1.
(i) Neurone P:__________

(ii) Neurone Q:__________

(b) Name the structure labelled X at neurone Q.

(c) What is the function of structure X?

(d) Fill in the boxes below with the correct neurone for the impulse pathway.

(a)(i) Neurone P: Sensory neurone
(a)(ii) Neurone Q: Motor neurone

X = axon

X transmits impulses from the cell body to an effector.
For example: A muscle or a gland.


2.8 Effects of Drug Abuse on Health

Effects of Drug Abuse on Health
2.8.1 What are Drugs?
1. Drugs are chemical substance which can affect a person’s mind, emotion and body functions.
2. Useful drugs are used to treat patient in medicine.
3. Drug abuse occurs if it is used not for medical purposes.
4. Drug abuse can lead to addiction and health deterioration.


Types of drug and their characteristics

2.8.2 Effects of Drug Abuse on Body Coordination and Health

Drugs and their adverse effects

2.6 Hormonal Coordination in the Body

Hormonal Coordination in the Body

1. Hormones are the chemical substances produced by the ductless glands called endocrine glands.
2. Hormones are produced in a small quantity and are carried by the blood circulation system to all parts of the body.

2.6.1 Human Endocrine System
1. The endocrine system is made up of endocrine glands, which are ductless glands that secrete hormone directly into the bloodstream.

Human endocrine system and the location of endocrine glands

Endocrine glands
Function of hormone
Pituitary gland
•  names of hormones not required
•  Master gland that controls and regulates the secretion of hormones by other endocrine glands.
•   Controls the growth of body.
•   Controls the reabsorption of water.
•   Controls other endocrine glands like ovary and testes.
Thyroid gland
•  Thyroxine
(contains iodine)
•  Main source of iodine is seafood.
•   Controls metabolic rate.
•   Controls the physical and mental growth
•   Glucagon
Controls sugar level in the blood by:
•  Insulin converts excess glucose into glycogen.
•   Glucagon changes glycogen into glucose.
Adrenal glands
•   Adrenaline
(secreted during situations of emergencies, under stress, fear or anxiety)
Increase heartbeat.
Increase metabolic rate.
Increase breathing rate.
Converts glycogen into glucose.
the male sex hormones)
•   Testosterone
•  Controls the development of male secondary characteristics such as deepening of voice armpit hair and moustache.
•  Production of sperms.
the female sex hormones)
•   Oestrogen
•  Controls the development of female secondary characteristics such as development of breast and enlargement of pelvis.
•  Controls the menstrual cycle and ovulation.
•   Stimulates development of milk glands during pregnancy.

Effects of Hormonal Imbalance on Health
Effect of excessive hormone
Effect of deficiency of hormone
Growth hormone
•   gigantism
•  dwarfism
•  Increase metabolic rate
•  Increase heartbeat
•  Increase sweating
•  Protruding eyes
•  Metabolic rate decreases
•  Retarded growth in Children
Causes goitre
•  Shortage of glucose in the blood.
•  May lead to coma and fatal.
•  Diabetes Mellitus
High blood pressure.
•  High salt concentration in blood.
•  Blood sugar level increases.
•  Muscles weaken.
•  Ability to overcome stress reducing.
•  Excessive salt and water in the body (Addison disease).
•  Extremely masculine
•  Incomplete development of secondary sexual characteristics.
•  Immature sperms produced.
Extremely feminine.
Baby born before the complete gestation period.
•  Incomplete development of secondary sexual characteristics.
•  Irregular menstrual cycle
•  Infertility
•  Miscarriage

2.5.5 Voluntary Actions and Involuntary Actions

Voluntary Actions and Involuntary Actions

Voluntary actions are actions we are aware of and which are done according to our
2. Voluntary actions are controlled by the cerebrum.
3. Involuntary actions take place continuously and automatically in the body, without us
being consciously aware of them.

4. Involuntary actions are controlled by the medulla oblongata.

Comparison between voluntary actions and involuntary actions

2.4 Proprioceptors in Maintaining Balance and Body Coordination

Proprioceptors in Maintaining Balance and Body Coordination
1. The sense which helps us to detect position and movement of the limbs by using proprioceptors is known as the kinaesthetic sense.
2. Proprioceptor is a group of highly sensitive stretch receptors in muscle, tendons and ligaments.
3. Proprioceptors function to maintain body balance, body posture and coordinate the muscular activities.
4. Proprioceptors are important because they are sensitive to being stretched, twisted or compressed. They act as sensory organs.
5. Proprioceptors are able to respond to stimuli and send out nervous impulses along their nerves to the central nervous system.

6. Proprioceptors enable us to know the movement of our limbs without having to watch them.
7. Examples of activities which are helped by kinaesthetic senses are:
(a)  Playing piano
(b)  Cycling
(c)  Rock climbing
(d)  Wearing shirt
(e)  Clapping hands
(f)   Tying shoe laces without looking

2.3 Nervous Coordination

Nervous Coordination
  1. A stimulus is any change which occurs outside or inside the human body that brings about a response.
  2. A receptor is a cell in the sensory organ which detects stimulus and convert the stimulus into electrical impulses.
  3. There are five main types of sensory organs, the eyes, ears, tongue, nose and skin.
  4. The reaction to a stimulus is called response.
  5. A response may be in the form of movement, caused by muscles or in the form of secretions, produced by glands.
  6. Muscles and glands which respond to stimuli are called effectors.
  7. All receptors and effectors are connected to the nervous system by neurones.


Reflex actions
  1. A reflex action is a fast, automatic and involuntary response towards a stimulus. It is carried out without conscious by the brain.
  2. Reflex actions help us to survive and to protect us from dangerous situation. For example, jerking away of hand when in contact with a hot kettle.
  3. Reflex actions take place in the spinal cord.
  4. The path of reflex action is called a reflex arc.
Flow chart showing reflex action occurring through the spinal cord

Example of reflex action when hand is pricked by a sharp nail