A & P - Nervous System Flashcards
name the structures associated with the central and peripheral nervous system
Central - brain and spinal cord
peripheral - cranial and spinal nerves
name the functions of the somatic nervous system
motor - skeletal muscle
sensory - pain, temp, touch, pressure, proprioception
special senses
name the two arms of the autonomic nervous system
sympathetic and parasympathetic
what is the function of a neurone?
relays info between CNS and PNS or other body systems
what is a nerve and what is its function?
a bundle of axons which carries info to and from the CNS and the rest of the body
how many cranial nerves are there and where do they arise from?
12 pairs
brain
how many spinal nerves are there and where do they arise from?
31 pairs
spinal cord
what is the function of the thalamus?
relay station for sensory information
where are the thalamus and hypothalamus found?
diencephalon
what is the function of the thalamus and hypothalamus
integrating centre for information
hormone secretion - temp, hunger, thirst regulation
what is the function of the cerebellum?
coordinates movement
maintains balance, posture, muscle tone
name the three areas of the brainstem
midbrain, pons, medulla
what is the function of the brainstem?
vital centres - respiratory and cardiovascular
which cranial nerves arise from the brainstem?
III to XII
what is the function of the hypothalamus?
hormone secretion
integrating centre of ANS
thermoregulation
hunger and thirst centres
what are the sulci of the cerebrum?
fissures in the brains surface
what are the gyri of the cerebrum?
ridges of the brains surface
what do the connecting fibres in the cerebrum consist of?
white matter
what is the basal ganglia of the cerebrum made of?
grey matter - nerve cell bodies
name the 4 lobes of the cerebrum
frontal
partial
temporal
occipital
what are the functions of the frontal lobe?
motor cortex intellect planning mood social judgement
what are the functions of the partial lobe?
somatosensory cortex
general sensation
taste
what are the functions of the temporal and occipital lobes?
auditory
visual
where in the cerebrum are the post and pre-central gyrus?
either side of the central sulcus
what are the functions of the pre and post - central gyrus?
pre - primary motor cortex
post - primary sensory cortex
what is the protective layer between the brain and skull called?
the meninges
name the three layers of the meninges
Pia mater
arachnoid mater
Dura mater
between which layers of the meninges is the subarachnoid space?
arachnoid mater and pia mater
what is contained in the subarachnoid space?
cerebrospinal fluid
which mater follow the contours of the brain? which do not?
pia mater - does
dura mater and arachnoid mater - don’t
what is the structure and function of the ventricular system in the brain?
ventricles are interconnecting cambers that produce cerebrospinal fluid
what are the functions of cerebrospinal fluid?
supports and protects brain
acts as shock absorber
keeps brain and spinal cord moist
where is cerebrospinal fluid secreted from?
choroid plexuses
which arteries supply the brain?
internal carotid
vertebral
what could cranial nerves carry?
motor fibres
sensory fibres
both
do cranial nerves carry parasympathetic fibres?
yes - in 4 pairs
name the cranial nerves in order
I - olfactory (smell) II - optic (vision) III - oculomotor (eye movement) IV - trochlear (look up and down) V - trigeminal (facial movement) VI - abducens (look side to side) VII - facial (taste & smile) VIII - vestibulocochlear (hearing) IX - glossopharyngeal (taste & speech) X - vagus (digestion & heart rate) XI - accessory (shoulder shrug) XII - hypoglossal (tongue movement)
name the layers of the spinal meninges, from inner to outer
pia mater
arachnoid mater
dura mater
what is the conus medullaris?
the tapered end of the spinal cord
what is the cauda equine?
where the spinal cord ends and nerves becomes loose like a horses tail
where in the spine would a lumber puncture be performed?
below L1 where the spinal cord stops
name the regions of peripheral nerves and the number in each region
cervical - 8 thoracic - 12 lumber - 5 sacral - 5 coccygeal - 1
name a type of single polarised cell
epithelial cells
name a highly polarised cell
neurone
name the two major types of cell in the nervous system
neurons - conduct impulses
glia - support neurons
name three different structure types of neurons
unipolar
bipolar
multipolar
which is the most common type of neuron in the nervous system?
multipolar
describe the flow of information through the neuron
dendrites to cell body to axon
which cells in the nervous system can divide?
glia
which cells are brain cancers most likely to arise from?
glia
name 4 types of glia in the CNS and their function
astrocytes (astroglia) - waste removal
oligodendrocytes - myelin production
ependymal cells - cerebrospinal fluid production
microglia - immune function
name a type of glia in the PNS and their function
Schwann cells - myelin production
what are the differences and similarities between Ogliodendrocytes and Schwann cells?
both make myelin sheath
Ogliodendrocytes - in CNS / have many axons
Schwann cells - in PNS / have single axon
what does grey matter consist of?
nerve cell bodies
where is grey matter located?
brain - outside (cortex / basal nuclei)
spinal cord - inner part
where is white matter located?
brain - inner part
spinal cord - outer part
what does white matter consist of?
axons and myelin
which two processes do most neurons have?
axons
dendrites
what do neurons have in common with other cells?
has cell body with cytosol and organelles
cell membrane
what makes neurons unique to other cells?
can’t reproduce
can trigger action potential
what can nerve cells communicate with?
other nerve cells
muscles
glands
where do charged ions want to move to?
from an area of high to low concentration
to an area of opposite charge
what can stop charged ions from moving along their concentration/charge gradient?
channels and pumps can be made to stay closed or forced to work
what is the membrane potential?
the difference in charge from different ions inside and outside the cell
why is a resting cell polarised?
the inside is negatively charged and the outside is positively charged
which ion is more abundant outside of a resting cell?
sodium (Na+)
what is there lots of inside a resting cell?
protein
describe the stimulation of an action potential
neuron stimulated
sodium channels open
sodium rushes into cell
cell becomes depolarised (reversal of electrical potential)
describe how the cell repolarises following stimulation
sodium channels close
potassium channels open
K+ moves out of cell
cell returns to negative state inside cell (repolarisation)
are action potentials of a fixed size?
yes - all or nothing response
if the cell has a greater membrane potential what will the stimulus need to be to trigger an action potential?
stimulus needs to be greater (eg. -70mV needs less stimulus than -90mV)
what is the function of myelin on the axon?
insulates the axon so flow of sodium ions (Na+) can travel quickly
what happens if the myelin on the axon is damaged or destroyed?
action potential moves slowly down neuron and dissipates more quickly
name two types of synapse and the difference between them
electrical - cytoplasm of one neuron touches the next
chemical - gap between neuron
what enters the presynaptic neuron when an action potential reaches the axon end?
calcium - via calcium channels
what is calcium needed for in the presynaptic neuron?
to form vesicles of neurotransmitter
how does the action potential pass from the pre to the post synaptic neuron?
the presynaptic neuron releases neurotransmitter which receptors on the postsynaptic neuron detect, opening ion channel to allow sodium to flood in.
name 7 neurotransmitters
serotonin dopamine acetylcholine GABA glutamine noradrenaline adrenaline
give three alternative names for a sensory neuron
afferent
somatic
visceral
give three alternative names for a motor neuron
efferent
somatic
visceral
describe the direction of impulse travel along the afferent and efferent nerve
afferent - away from stimulus
efferent - to effector muscle or gland
what is the Glasgow Coma scale used for?
rapid assessment of consciousness level - checks for correct functioning of nerves
outline the Glasgow coma scale scores
8 or less - severe
9-12 - moderate
13 or more - mild to normal
what happens to the action potential when the spinal cord is severed?
action potential can’t move down neurons
what happens to the action potential following stroke?
brain cell death occurs so action potential not triggered
what happens to the brain in Alzheimer’s disease?
neurons make too much protein leading to tangling and cell death
when is the sympathetic division of the nervous system most active?
4 F's fight flight fright fuck
describe the body’s response to stimulation of the sympathetic nervous system
increased: HR, blood pressure, blood flow to muscles, blood sugar levels,
inhibited: GI peristalsis
relaxes airway
pupil dilation
orgasm
describe the body’s response to stimulation of the parasympathetic nervous system
decreased HR increased GI motility bronchial constriction pupil constriction gastric secretions
what does nicotine stimulate?
ACh receptors
what do nicotinic receptors control?
ion channels
where are nicotinic receptors found?
CNS
ANS ganglia
neuromuscular junction
does the central nervous system or the peripheral nervous system control the ANS?
CNS via hypothalamus
name the three neural outputs of the CNS
somatic motor
sympathetic
parasympathetic
describe the pre and post ganglionic fibres of the sympathetic nervous system
pre - short
post - long
describe the pre and post ganglionic fibres of the parasympathetic nervous system
pre - long
post - short
what does the ANS innervate?
smooth muscle
cardiac muscle
gland cells
what is a ganglion?
a collection of nerve cell bodies
name two classes of acetylcholine receptor
nicotinic
muscarinic
where are nicotinic receptors located?
sympathetic ganglionic synapse
parasympathetic ganglionic synapse
where are muscarinic receptors located?
parasympathetic post ganglionic synapse
which neurotransmitter is used in all preganglionic ANS neurons?
acetylcholine
which neurotransmitter does the parasympathetic nervous system use in the pre and post ganglionic neurons?
acetylcholine - both
which neurotransmitter does the sympathetic nervous system use in the pre and post ganglionic neurons?
pre - acetylcholine
post - noradrenaline
which receptor is at the preganglionic synapse in the sympathetic nervous system?
nicotinic
which receptor is at the postganglionic
synapse in the sympathetic nervous system?
adrengenic
explain how adrenaline and noradrenaline are released in the adrenal medulla
acetylcholine acts on nicotinic receptors in the ganglion to release adrenaline and noradrenaline quickly
what are muscarinic receptors blocked by?
atropine (antagonist belladonna)
what are nicotinic receptors blocked by?
curare (antagonist)
which receptor is at the preganglionic synapse in the parasympathetic nervous system?
nicotinic
which receptor is at the postganglionic synapse in the parasympathetic nervous system?
muscarinic
which hormone is released from the adrenal cortex and why?
cortisol - in response to stress
how does cocaine and amphetamine
affect the sympathetic nervous system?
prolongs action of noradrenaline (and serotonin and dopamine
what does the enteric division do?
controls a lot of food transport and digestion
give examples of problems with the ANS
orthostatic hypotension (low BP on standing)
inability to sweat/excess sweating
severe constipation
impotence
give some examples of reasons why there may be problems with the ANS
diabetes old age drug/medication autoimmune degradation of nerves spinal injury brain tumours
