The nervous system Flashcards
what are the two parts of the nervous system
Central nervous system
peripheral nervous system
what is the central nervous system made up of
brain
spinal chord
what is the peripheral nervous system made up of
cranial nerves
spinal nerves
The peripheral nervous system is made up of 2 parts, what are they. are they voluntary or involuntary
somatic nervous system (voluntary)
autonomic nervous system (involuntary)
what is the somatic nervous system divided into
motor (skeletal muscle)
sensory (pain, temp, touch, pressure, special senses)
what is the autonomic nervous system divided into
sympathetic (fight or flight)
parasympathetic (rest and digest)
what is a neurone
a single nerve cell (basic functional unit of the nervous system)
relays information between different regions of the CNS and PNS
draw and label an neurone
draw it
what is a nerve
a bindle of axons carrying information from the CNS to the rest of the body or vice versa
nerves enter and leave the CNS from the brain and spinal cord, how many nerves arise from each
12 pairs from the brain (cranial nerves)
31 pairs from the spine (spinal nerves)
draw the brain and label it
draw it
what is the cerebellum responsible for
maintenance of... balance posture muscle tone coordinates movement
what is the brain stem responsible for (3 things)
1) continuous with the spinal cord, everything from body to brain goes through brain stem
2) crainial nerves III-XII arise from brain stem
3) contains vital centres such as cardiovascular and respiratory centres
what is the diencephalon responsible for (3 things)
made up of the…
thalamus (relay station for sensory information)
hypothalamus (homeostasis)
what is the cerebrum responsible for
With the assistance of the cerebellum, the cerebrum controls all voluntary actions in the body
It has 2 hemispheres (made up of sulci - dip & gyri - peak)
cortex - outermost layer made up of grey matter
connecting fibres - white matter
basal ganglia - grey matter (control of voluntary motor movements, procedural learning, routine behaviours or “habits” such as bruxism, eye movements, cognition and emotion)
what is the name of the gap in between the 2 hemispheres of the cerebrum
longitudinal fissure (groove, natural division)
what are the 4 lobes of the cerebrum and what is each lobe responsible for
frontal lobe - movement, intellect, social judgement)
parietal lobe - sensory cortex (sensation and taste)
temporal lobe - auditory cortex (hearing)
occipital lobe - visual cortex
look at and poss draw ‘organisation of cerebrum’ image on page 3 of The Nervous System slides
draw it
what are the meninges
membranes that envelope the CNS
what are the 3 layers of the meninges from outer to inner
Dura matter - tough, durable, stops brain rotating
Arachnoid mater - lots of fibers
Pia mater - fine covering
where is the subarachnoid space and what does it contain
between the arachnoid mater and pia mater and contains CSF (cerebrospinal fluid)
what is the ventricular system
the ventricles are interconnecting chambers that produce CFS (bathes the brain)
what are the 3 functions of CFS
1) acts as a cushion or buffer for the brain’s cortex,
2) providing a basic mechanical and immunological protection to the brain inside the skull,
3) serves a vital function in cerebral autoregulation of cerebral blood flow.
describe the blood supply to the brain main up of
blood supplied to the brain by the internal carotid arteries and vertebral arteries
communicating arteries connect the branches of these vessels to form the ‘Circle of willis’
how many pairs of cranial nerves are there and what kind of nerves are they
12 pairs (10 from he brain stem)
May carry motor fibres, sensory fibres or both
(4 pairs also carry parasympathetic fibres)
what is the spinal cord supported and protected by
the vertebral column
at what point does the spinal chord terminate
at the conus medullaris (level L1)
how many pairs of spinal nerves are there and how many from which part of the spine do they branch from
31 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
what are the 3 layers of spinal meninges from the outside in
dura mater
arachnoid mater
pia mater
what is the conus medullaris and cauda equina
conus medullaris: the tapered, lower end of the spinal cord.
cauda equina: a bundle of spinal nerves and spinal nerve roots
draw both the spinal cord images (page 5 of The Nervous system)
draw it
what does the somatic nervous system do
interaction with the outside world e.g eyes, ears, balance
what are neuroglia
cells that support neurons, provide nutrition
why is grey matter grey
contains nerve cell bodies
why is white matter white
contains axons
does the nervous system have internal connective tissue for support
no - its has supporting cells called neuroglia
what are the 4 types of neurones (look at images)
no axon
bipolar
unipolar
multipolar
nerve cells communicate with…
other nerve cells
muscle
glands
what does a mylinated axon mean
faster conduction
what is the name of the cells which produce myelin
peripheral NS - Schwann cells
Central NS - oligodendrocytes
how do nerve cells communicate with each other
electrical signals called action potentials
describe the resting membrane potential
inside the neurone is negative compaired to the outside (polarised at -70 to -80 mV)
lots of sodium (Na+) outside
what are the 3 stages of depolarisation
sodium channels open (na+)
sodium moves in
inside then becomes positive
what are the 4 stages of repolarisation
sodium channels close
potassium channels open
potassium moves out
return of electrical potential to -ve inside
action potentials are known as what meaning they do not fire unless a certain voltage is reached
‘all or none’
what does the presynaptic neurone release into the chemical synapse
neurotransmitter
what is the autonominc nervous system made up of
sympathetic and parasympathetic nervous system
what are the neurotransmitters at both the pre and post ganglions of the sympathetic and parasympathetic nervous systems
sympathetic: pre - acetylcholine, post - noradrenaline
parasympathetic: pre - acetylcholine. post - acetylcholine
what is a ganglion
a ganglion is a nerve cell cluster or a group of nerve cell bodies outside of the central nervous system
what is the autonomic nervous system
is the part of the peripheral nervous system that acts as a control system that functions largely below the level of consciousness to control visceral functions,[1] including heart rate, digestion, respiratory rate, salivation, perspiration, pupillary dilation, micturition (urination), sexual arousal, breathing and swallowing. Most autonomous functions are involuntary but they can often work in conjunction with the somatic nervous system which provides voluntary control.
when is sympathetic nervous system most active
during exercise or stress
what happens during the fight or flight response
increased HR increased BP increased blood flow to muscle pupil dilation bronchial dilation inhibition of GI peristalsis
what kind of receptor accepts acetylcholine as its neurotransmitter
cholinergic receptors - either nicotinic or muscarinic receptor (different mode of action) muscarinic = parasympathetic, nicotinic = both
what kind of receptor accepts noradrenaline as its neurotransmitter
adrenergic receptors - Alpha or Beta (eg beta 2 = bronchioles)
what does nicotine to
stimulates nicotinic receptors which are found in the CNS, ANS ganglia and neuromuscular junction
what is a ligand
eg: acetycholine or noradrenalin - something that binds to a receptor
in the sympathetic nervous system the paravertebral ganglia go from the what to the what
thoraco-lumba outflow spinal cord to the vessels of the skin, skeletal muscle, sweat glands
in the sympathetic nervous system the prevertebral ganglia go from the what to the what
thoraco-lumba outflow spinal cord to the eye, salivary gland, bronchi, heart, adrenal gland, gut, renal/hepatic vessels, bladder, genitalia
which gland is associated with the sympathetic nervous system
adrenal gland (adrenal medulla)
adrenal medulla derived from neuronal tissue.
releases mostly Adrenaline but some Noradrenaline
how does cocaine work?
enhances sympathetic effects by prolonging action of neurotransmitter Noradrenaline (and serotonin and dopamine)
what is the parasympathetic nervous system said to be associated with
‘rest and digest’
what happens when the parasympathetic nervous system is stimulated
decreased heart rate increased GI motility bronchial constriction pupil constriction gastric acid secretion
what are muscarinic receptors blocked by (antagonist)
atropine
what are nicotinic receptors blocked by (antagonist)
curare
what are the autonomic effector tissues
Eye skin kidney vessels skeletal muscle vessels Heart (rate/stroke volume) respiratory tract (bronchioles)
where is the location of the ganglia in sympathetic nervous system
paravertabral
where is the location of the ganglia in parasympathetic nervous system
close to the effector
is the sympathetic nervous system anabolic or catabolic
catabolic (fight or flight)
is the parasympathetic nervous system anabolic or catabolic
anabolic (rest & digest)
where is the outflow from the spinal cord for the parasympathetic nervous system
Cranio - sacral outflow
Cranio (medullary) - eyes, salivary glands, heart, lungs, upper GI
Sacral - lower GI tract, bladder, kidneys, genitalia
in the parasympathetic NS where do nerves leave the spine
cranio-sacro outflow to the eye salivary glands, heart, lungs, upper GI, lower GI, bladder, kidney genitalia
