Page 37 - Biology_Form_3

Coordination in animals

Cranial nerves Procedure
Cranial nerves are pairs of nerves that 1. Use locally available materials to
connect the brain to different parts of the create a model of the human brain
head, neck, and trunk. There are different and spinal cord.
cranial nerves, each being named depending
FOR ONLINE READING ONLY
on its function or structure. An example of 2. Label and describe the parts of the
cranial nerves includes olfactory nerves brain.
which transmit sensory information Question
regarding smell to the brain from the nose, 1. Identify the regions of the brain.
optic nerves which link the eyes and brain, Comment on their size.
and vestibulocochlear nerves which are
involved in hearing and balance of the body. 2. Describe the functions of the specific
parts indicated on the created model
Hypothalamus of the human brain.
The hypothalamus is a small region of
the brain located at the base of the brain Spinal cord
near the pituitary gland. Although it is The spinal cord runs from the head to the
very small, it plays an important role in end of the trunk and is encased in meninges.
maintaining homeostasis by ensuring the It lies in the canal of the vertebral column
body regulates a balance in temperature, and thus it is protected from mechanical
fluids, metabolism, hormones and stress injury. A cross section of the spinal cord in
responses. It also controls involuntary Figure 2.9 shows that it is made up of two
activities such as appetite and sleeping. identical halves. The two halves enclose the
spinal canal which is at the centre of the
Pituitary gland spinal cord. The spinal canal is filled with
The pituitary gland is a small pea-sized cerebrospinal fluid, which helps to protect
gland that plays a role in regulating vital the spinal cord from shocks. The inner
functions and general wellbeing of the region of the spinal cord consists of grey
body. It is referred to as the master gland matter. The grey matter is grey in colour
because it controls the activity of most due to high concentration of cell bodies of
other hormone-secreting glands. neurones. The cell bodies transmit impulses
between sensory and motor neurones. The
Activity 2.3: outer region of the spinal cord consists of

Creating a model of the structure of brain white matter. The white matter is composed
and spinal cord of the nerve fibres or axons of sensory and
motor neurones. The myelin sheath of the
Materials nerve fibres gives this region the white
Locally available materials to make the colour. These nerve fibres are known as
model, glue, card boards spinal nerves. The spinal nerve divides

30

23/10/2025 11:52:34
BIOLOGY FORM 3 FINAL EDITED 16.09.2025.indd 30 KAMISHNA 23/10/2025 11:52:34
BIOLOGY FORM 3 FINAL EDITED 16.09.2025.indd 30

KAMISHNA