13.6 Organisation of the nervous system Flashcards
what are the two main divisions of the nervous system
Central nervous system
Peripheral nervous system
what’s the CNS made up of
the brain and spinal cord (relay neurones)
what’s the PNS made up of
- all the neurones that connect the CNS through the rest of the body
- sensory neurones that connect sensory receptors to the CNS
- motor neurones that connect the CNS to effectors (muscles and glands)
what two divisions does the PNS split into
the autonomic nervous system and the sonomatic nervous system
what’s the automatic nervous system and where does it pass electrical impulses to
it’s a nervous system that works constantly under subconscious control it’s used when your body does something automatically eg breathing or heart beating
the electrical impulses pass to the involuntary cardiac muscles and smooth muscles (eg the walls of intestines) via the ANS
what’s the somatic nervous system and where does it pass electrical impulses to
it’s used under conscious control ie. when your body does voluntarily decide to do something
eg. moving a muscle the electrical impulses does called the the SNS to the skeletal muscles
what two divisions does the SNS split into
sensory nervous system (afferent) (sensory input)
motor nervous system (efferent) (motor output)
what two divisions does the ANS split into
the sympathetic division
and the parasympathetic division
what does the sympathetic division do
it increases activity
and gets body ready for fight or flight and releases the neurotransmitter noradrenaline
eg. dialates pupils
inhibits salivation
relaxes bronchi
accelerates heartbeat
stimulates glucose production and release
inhibits bladder contraction
what does the parasympathetic division do
it decreases activity and tells body to rest and digest, releasing neurotransmitter acetylcholine
it, constricts pupils
stimulates silva flow
constricts bronchi
slows heartbeat
contracts bladder
what neurotransmitter is released in the somatic nervous system
acetylcholine
