2. Coordination: is the way
all the organs and
systems of the body are
made to work efficiently
together.
For example, when muscles are being used
for running they need extra glucose and
oxygen. So we increase the breathing rate
to obtain extra oxygen and the heart
pumps more rapidly to take de oxygen
and the glucose to the muscles more
quickly.
The brain detects changes in O2 and CO2 in
the blood and sends nervous impulses to
the respiratory muscles and heart in order
to increase their activities. This is one
example of coordination, between mane
organs.
4. The human nervous system.
The brain and spinal
cord form together
de CENTRAL
NERVOUS SYSTEM.
Nerves carry electrical
impulses, from the
central nervous
system to all parts of
the body, making
muscles contract.
5. The nerves which connect the
body to the central nervous
system make up the
PERIPHERAL NERVOUS
SYSTEM.
Muscles are called
EFFECTORS because they
go into action when they
receive nerve impulses.
6. Nerve impulses from From the central nervous
the sense organs system, this impulses are
(skin, eye, ears) to the carried to the
central nervous EFFECTORS, resulting in
system are called action. These are called
SENSORY
MOTOR IMPULSES.
IMPULSES. This is
the way by which
information from the
peripheral receptors
travel to the central
nervous system.
7. SENSORY MOTOR
NEURONE NEURONE
CENTRAL
NERVOUS
SYSTEM. EFFECTOR.
RECEPTOR
MUSCLES.
STIMULUS RESPONSE
8. Nerve cells. NEURONES.
The central nervous system, and the peripheral nerves
are made up of neurones.
MOTOR NEURONE MULTI POLAR SENSORY NEURONES
NEURONES
Carry impulses from Are neither sensory nor Carry impulses from
the central nervous motor but make the sense organs to the
system to the muscles. connections to other central nervous system.
neurones inside the
central neorvous
system.
9. CLASSROOM ACTIVITY:
From page 164, read NERVE CELLS.
Draw and label the three types of neurones.
Give at least 2 structural differences between
sensory and motor neurones.
Give one functional difference between a sensory
and a motor neurone.
10. Synapse
It is necessary for impulses to pass from one neurone to
another. The regions where impulses are able to cross
from one neurone to the next are called SYNAPSES.
At a synapse a branch at the end of one fibre is in close
contact with a dendrite of another neurone. When an
impulse arrives at the synapse, it releases a tiny amount of a
chemical substance called a NEUROTRANSMITTER
SUBSTANCE, which sets off an impulse in the next neurone.
11.
12. The NERVE IMPULSE
The impulse is a series of electrical pulses,
which travel down the fibre. All the impulses
are similar.
The difference is that each impulse is sent to
different parts of the brain.
For example, the nerves from the aye go to the part of the
brain concerned with sight. Then the brain recognizes
that the impulses comes from the aye and we SEE
something.