Responding to the environment
The nervous system (involving nerves) and the endocrine
system (involving hormones) help us to respond to the
environment.
,Why do we need a nervous system?
Our survival depends on us being sensitive to our
surroundings. We need to be able to detect any changes in
the environment and be able to react to these changes.
A characteristic of a living organism is irritability i.e. the ability
to respond to stimuli.
The stimuli may be external (received by sense organs) or
internal (received in body by nerve endings).
This must also be able to co-ordinate the various activities of
the body.
, The Nervous system and
transmission of impulses
A nervous system is needed to:
Detect changes in the environment (both internal and
external) and to react to these changes ✔
Coordinate the various activities of the body ✔
, (voluntary actions) (involuntary actions)
(Cranial and spinal nerves)
The nervous system (involving nerves) and the endocrine
system (involving hormones) help us to respond to the
environment.
,Why do we need a nervous system?
Our survival depends on us being sensitive to our
surroundings. We need to be able to detect any changes in
the environment and be able to react to these changes.
A characteristic of a living organism is irritability i.e. the ability
to respond to stimuli.
The stimuli may be external (received by sense organs) or
internal (received in body by nerve endings).
This must also be able to co-ordinate the various activities of
the body.
, The Nervous system and
transmission of impulses
A nervous system is needed to:
Detect changes in the environment (both internal and
external) and to react to these changes ✔
Coordinate the various activities of the body ✔
, (voluntary actions) (involuntary actions)
(Cranial and spinal nerves)
