#1 u3aos1 - central and peripheral nervous system (ch3a) Flashcards
nervous system
2 marks
a network of specialised cells.
connects different parts of the body to the brain
CNS (central nervous system)
3 marks
occupies a central position of the body.
made up of the brain and the spinal cord.
processes and coordinates responses to sensory stimuli
neuron
3 marks
specialised nerve cell.
recieves, transmits and processes information within the nervous system.
three classes of neurons
3 marks
sensory neurons
motor neurons
interneurons
two types of neurons
2 marks
afferent neurons (incoming)
efferent neurons (outgoing)
sensory neurons
3 marks
known as afferent neurons.
nerve cells that carry sensory information from the body towards the CNS (central nervous system)
motor neurons
3 marks
known as efferent neurons.
nerve cells that carry motor information away from the CNS, towards the rest of the body.
interneurons
3 marks
a nerve cell in the spinal cord.
connects motor and sensory neurons by relaying (passing along) messages between the two.
brain
5 marks
a complex structure
recieves and processes sensory stimuli from the body and coordinates responses including:
- voluntary movements
- emotions
- conscious thoughts
what makes up the central nervous system (CNS)
2 marks
- spinal cord
- brain
cranial nerves + example
3 marks
nerves in the brain that connect directly to organs and muscles.
are considered to be apart of the CNS.
eg:
the vagus nerve directly connects to the stomach and intestine, controlling digestion.
spinal cord
3 marks
a dense bundle of nerves
carries sensory information from the brain to the body
carries motor information from the body to the brain
which component of the CNS is involved in the spinal reflex?
1 mark
spinal cord
spinal reflex
4 marks
an unconcious
involuntary response
to certain stimuli
which is controlled by the spinal cord rather than your brain
Why is it more effciient for the spinal cord to be involved in the spinal reflex response?
2 marks
enables a faster reaction time
minises harm that might occur as a result of the stimuli
spinal reflex process
6 marks
- sensory stimulus is deteced by sensory receptors.
- sensory neurons carry sensory information to the spinal cord
- interneurons in the spinal cord recieve and process the sensory information
and initiate an involuntary motor response - motor neurons carry this motor message to the muscles.
- the muscles perform the spinal reflex
brains input in the spinal reflex process
4 marks
- when spinal reflex is occurring, sensory information is carried further up the spinal cord towards the brain
- sensory message is recieved by the primary somatosensory cortex in the parietal lobe of the brain
information is processed and interpreted - brain consciously decides to make a further response
peripheral nervous system (PNS)
2 marks
consists all the nerves outside the CNS
enables the CNA and the rest of the body to communicate
how does sensory information travel in the PNS
1 mark
body’s muscles, organs, glands -> CNS
how does motor information travel in the PNS
1 mark
CNS -> body’s muscles glands, organs
somatic nervous system
3 marks
a subdividsion of the PNS
connects the CNS to the sensory receptors
and skeletal muscles in the body.
somatic nervous system:
CNS recieves sensory information from the skeletal muscles in the body to…
1 mark reasoning
3 marks examples
feel bodily sensations such as:
- touch
- taste
- temperature
- pain
somatic nervosu system:
CNS sends motor information to the skeletal muscles in the body to…
1 mark for reasoning
3 marks examples
enables voluntary body movements
- walking
- chewing
- typing
autonomic nervous system
3 marks
a subdivision of the PNS
connects the CNS to the body’s non-skeletal muscles
and glands
2 subdivisions of the autonomic nervous system
2 marks
sympathetic nervous system
parasympathetic nervous system
sympathetci nervous system
4 marks
subdivison of autonomic nervous system
increases arousal
prepares the body to quickly respond to situations
dominates when we are under threat
when is the sympathetic nervous system useful
4 marks
- during threatening/stressful situations
- activates the fight-flight-freeze reponse
- undergoing vigorous activity
- increases activity of some bodily systems while slowing down others.
characteristics of sympathetic nervous system
4 marks (for any 4 listed)
- dilates pupils
- inhibits salivation
- increase heartbeat (heart rate does not count)
- inhibit digestion
- inhibit activity of intestines
- stimulates glucose release
- stimulte adrenaline release
parasympethetic nervous system
4 marks
subdivision of autonomic nervous system
maintains homeostasis (body’s internal environments)
in a self regulated manner
for nomal day-to-day function
when is the parasympethatic nervous system useful
3 marks
useful when the body is relaxed or to bring the body to this state
reverses the effects of the sympathetic nervous system
to restore bodily functioning
characteristics of parasympathetic nervous system
4 marks (for any 4)
- constricts pupils
- stimulates salivation
- decreases hearbeat
- stimulates digestion
- stimulates activity of intestines
- constricts airways
- contracts bladder
