The brain, located within the cranium, is suspended in cerebro-spinal fluid and surrounded by membranes, controlling both voluntary and involuntary body functions. It consists of two hemispheres with specific areas for distinct functions, including the cerebrum for complex activities, the cerebellum for balance, and the medulla oblongata for automatic processes. The spinal cord connects the brain to the body through peripheral nerves for voluntary actions and the autonomic system for involuntary functions.

1. THE BRAIN
 The brain is located inside cranium ( the cranium acts
as a protective outer layer for the brain). It is
suspended in Cerebro-spinal fluid and surrounded by
membranes known as Meninges. The brain controls
both voluntary and involuntary reactions that occur in
the body. Your brain is divided into two hemispheres,
the left and right hemispheres respectively, and each
part of the brain has a specific function to control part
of the body.

2. THE BRAIN
: Brain Segment Function of the Segment
CEREBRUM
(forebrain)
Divided into regions dealing with specific
functions. Greatly folded so increases the
number of cells present
CRANIUM Made of bones fused together to form fixed
joints. Protective outer layer surrounding
the brain.
CEREBELLUM
(hind-brain )
Controls balance, posture and learned skills
HYPOTHALAMUS
(forebrain)
Controls water balance and temperature
within the body
MEDULLA OBLUNGATA
(hind-brain)
Controls automatic activities, e.g. Heart rate,
breathing etc.
PITUITARY GLAND
(forebrain)
Controls numerous activities such as water
balance (ADH) and growth (GH). It is also
known as the master gland.
OPTIC LOBES
(Mid- brain)
Concerned with sight and eyeball
movement

3. Diagram of the Brain

4. CNS continued-Spinal Cord
 Runs from the base of the brain to base of the lumbar
region of the back and is protected by the vertebrae.
Extending out of the spinal cord are transverse spinal
nerves which extend throughout the rest of the body
and forms a network connected to various motor and
sensory neurones.

5. Peripheral and Autonomic Nervous
System
 Peripheral Nervous system – Contains the nerves
running to and from the central nervous system. There
are the Cranial and Spinal nerves and are responsible
for voluntary actions.
 Autonomic nervous system – Responsible for the
involuntary actions of the internal muscles / glands
within the body. e.g speeding up and slowing down of
the heart.