eyes, ears, tongue, nose
and skin are sense organs
all of these contain different
receptors, these receptors are
a group of cells that are
sensitive to a certain stimulus
they chang the stimulus energy(E.G
light energy) into electrical impulses
examples of stimulus: light,
sound, pressure, touch, pain
or temperature
light receptor
cells are like
most animal
cells
Central Nervous system
coordinates a response to
detected stimulus
CNS is sent all information
from sense organs
from which reflexes and
actions are coordinated
CNS is the brain and
spinal cord ONLY
instructions from the CNS are sent to the
effectors which respond accordingly
This can be a reflex for
example, reflexes help
prevent injury as its an
automatic response
Passage of information in a reflex is called a reflex arc.
neurones(nerve
cells) transmit
information quickly
as electrical
impulses to and
from the CNS
The impulses
movement
receptors in sense
organs: detect stimuli
sensory neurones: nerve cells
that carry signals as electrical
impulses from receptor in sense
organs to CNS
synapse
relay neurone: nerve cells that
carry signals from sensory
neurones to motor neurones
synapse
Motor neurones: nerve cells that carry
signals from the CNS to the effector
muscles or glands
glands respond by
secreting(releasing)
chemical substances
synapses connect
neurones. the nerve
signal arrives as
electrical impulses
then the signal is
transferred by
chemicals which
diffuse across the
gap, these chemicals
then set off a new
electrical charge in
the next neurone