3. The nervous
system is an
internal
communication
system that sends
short electrical
impulses. Its main
component is the
nerves.

4.  Nerves carry information and instructions
to and from the brain.
 The way a nerve works is through a chain
of nerve cells that carries a signal (as an
electrical impulse) to or from the brain and
it is received by the nerve endings of other
nerve cells.
 There are three types of nerves: sensory
nerves, motor nerves and mixed nerves.

5.  Theybring information from the eyes, ears
and other sense organs to the brain.
 Motor nerves are the nerves responsible
for all voluntary skeletal and somatic
movement.
 Thesenerves contain both motor and
sensory fibers.

6.  The longest nerve we have is the tibial
nerve. It is 50 cm in adults.
 We have thousands of nerves distributed
among all our body.
 “pins and needles”
 The slowest nerves travel at about 1 mps,
and the fastest ones travel at 100 mps.
 Reflex action.

7.  Howis the information transmitted to the
body?
 Which are the three types of nerves?
 What causes „pins and needles‟?
 What is the axon‟s role?
 How do you make your body move?