1. The Nervous
What does the
Nervous System do?
System
The Nervous System is the body’s control and
communication system. Nerves carry instant
messages from the brain to every part of the body
and back again, so it can process the information
and make any adjustments.
2. What body parts are in the
Nervous System?
The brain and the Spinal Cord are
the main parts of the Central
nervous system, which is further
divided into the Peripheral and
Autonomic nervous systems.
3. The Brain
The BRAIN is a delicate organ made from more than 100
billion nerves cells called neurons and is protected by the
skull. Each Neuron is connected to as many as 25,000
other neurons so the brain has many trillions of different
pathways for nerve signals.
4. The Spinal Cord
The spinal cord is a bundle of nerves that runs
down a tunnel in the middle of the back bone,
and is the route for all nerve signals travelling
between the brain and the body.
The outside of the spinal cord is made up of
long tails (axons) of nerve cells and is called
white matter. The inside is made up of the
main nerve bodies and is called grey matter.
5. This picture shows the position of
the spinal cord protected by the
vertebra bones with the spinal
nerves branching off.
The spinal cord is about 43cm
long and 1cm thick, and it stops
growing when you are about 5
years old.
6. Nerve Cells
Nerve cells link together
to form the nervous
system, like beads on a
string.
Electrical signals from
one nerve cell pass along
its tail (axon) to other
nerve cells within the
system.
7. These green lines are all
the major nerves in the
body, there are many more
smaller ones.
The longest and largest
nerves are the sciatic
nerves, which are as
wide as your thumb!
They start at your lower
back and run right down
your legs to your little
toes.
8. The Cranial nerves
The green lines are cranial
nerves.
The pink one is the spinal cord.
9. C.N.S.
The central nervous system (CNS) maintains
all bodily functions that keep us alive and
can adjust according to the surroundings.
E.g. body temperature. It is also
responsible for thoughts, emotions and
memories.
10. P.N.S.
The Peripheral nervous system (PNS) is
made up of the nerves that branch out in
pairs from the CNS to the rest of the body.
In the PNS there are 12 cranial nerves of
the head and 31 pairs of spinal nerves.
They are made of long bundles of nerve
fibre, like wires in a telephone cable.
11. A.N.S.
The autonomic system (ANS). The ANS controls
internal body processes that we don’t think about like
breathing and digestion.
The ANS splits into two further systems, the
Sympathetic and Parasympathetic. The Sympathetic
system speeds up body processes and the
Parasympathetic system slows them down again.
