Physiology Flashcards
1
Q
define the CNS
A
brain + spinal cord
2
Q
what are the components of the PNS
A
12 CN
31 SN
+ branches
3
Q
what percentage of cardiac output does the brain recieve
A
15%
4
Q
what percentage of oxygen usage does the brain take?
A
20%
5
Q
What are gyri, sulci and fissures?
A
gyrus = outward projection sulcus = inward projection fissure = deep sulcus
6
Q
what is the other name for the Sylvian fissure
A
lateral fissure
7
Q
what is the name of the fissure separating the 2 cortexes
A
cerebral interhemispheric
8
Q
what is the function of the corpus callosum
A
communication between hemispheres
9
Q
name the components of the brainstem in order from superior to inferior
A
midbrain, pons, medulla
10
Q
what is the main function of the thalamus
A
relay centre
11
Q
the LGN is part of what brain structure
A
thalamus
12
Q
the thalamus, hypothalamus, subthalamus and epithalamus are collectively known as what?
A
diencephalon
13
Q
what hormones does the hypothalamus synthesise
A
ADH, oxytocin
14
Q
the hypothalamus has a role in hormone release from the _____
A
anterior pituitary
15
Q
name the meninges from superficial to deep
A
dura mater
arachnoid
(subarachnoid space +CSF)
pia
16
Q
what arteries does the anterior circulation arise from
A
internal carotid
17
Q
what arteries does the posterior circulation arise from
A
vertebral arteries
18
Q
the IC bifurcates into the ….
A
MCA and ACA
19
Q
the ophthalmic artery is a branch of the ____
A
IC
20
Q
the anterior choroidal artery is a branch of the ___
A
IC
21
Q
what artery connects the right and left anterior cerebral arteries
A
anterior connecting artery
22
Q
what artery supplies the medial cerebral hemispheres
A
anterior cerebral arteries
23
Q
what artery supplies the lateral hemispheres, basal ganglia and the internal capsule?
A
middle cerebral artery
24
Q
what artery runs in the sylvian lateral fissure
A
middle cerebral artery
25
the vertebral arteries are a branch of the _____
subclavian arteries
26
the vertebral arteries pass through the _____ of C_ to _
through transverse foramen of C6-C2
27
the vertebral arteries join to form the ____ at the _____
join forming basilar at pons
28
the posterior inferior cerebellar arteries are branches of the _____
vertebral arteries
29
what artery terminates at the interpeduncular cistern?
basilar artery
30
the superior and anterior inferior cerebellar arteries are branches of the _____
basilar artery
31
what artery supplies the thalamus and occipital lobe
posterior cerebral arteries
32
the pontine arteries are branches of the _____
basilar artery
33
what structure does the dural venous sinuses drain to
internal jugular vein
34
is the superior sagittal sinus is paired or unpaired?
unpaired
35
the superior sagittal sinus goes from the anterior falx cerebri to the _____
confluence of the sinuses
36
is the calcarine sulcus is on the anterior or posterior aspect of the brain?
posterior
37
the cingulate sulcus is in the midline or lateral brain surface?
midline
38
During foetus development, there are 3 primary vesicles which give rise to the brain, what are their names?
prosencephalon
mesencephalon
rhombencephalon
ROMan PRO MESsage
39
Name the lobes of the brain
```
parietal
frontal
occipital
temporal
insular
limbic
```
40
What is the function of the insular lobe?
has a role in pain
41
the precentral gyrus of the frontal lobe contains the _____
motor cortex
42
the calcarine fissure of the occipital lobe contains the ____
visual cortex
43
the postcentral gyrus of the parietal lobe contains the _____
somatosensory cortex
44
the superior temporal gyrus of the temporal lobe contains the ____ and _____ on the dominant side
auditory cortex and wernicke's area
45
what is the function of wernicke's area
speech comprehesion
46
the inferior frontal gyrus of the frontal lobe on the dominant side contains _____
broca's area
47
what is the function of broca's area?
speech production
48
the micturition inhibition centre is part of which lobe?
frontal lobe
49
which lobe is responsible for executive function?
frontal lobe
50
which lobe contains the hippocampus
temporal lobe
51
what is the main function of the hippocampus
memory
52
which lobe contains the frontal eye feilds
frontal lobe
53
the amygdala is a part of the ____ system
limbic system
54
is the cerebellum directly above or below the tentorium cerebelli
below
55
does the cerebellum control ipsilaterally or contralaterally?
ipsilaterally
56
Name the structures that attach the cerebellum to the brainstem
superior, middle and inferior peduncles
57
Name the tree of white matter in the cerebellum
arbor vitae
58
Name the layers of the cerebellum from superficial to deep
outer molecular layer
middle Purkinje cell layer
inner granule cell layer
59
What is the name to the midline portion of the cerebellum?
vermis
60
What cell type sends efferents from the cerebellum
purkinje cells
61
Where to afferent inputs to the cerebellum arrive?
peduncles
62
What is the commonest cause of bilateral cerebellar disturbance?
Acute alcohol exposure
63
What type of information does the cerebellum receive and where doe sit send it?
receives sensory info for movement and sends it to thalamus
| also sends intented motor
64
the cerebellum receives sensory info for movement, where does it send it?
thalamus
65
where does the cerebellum send intended motor information?
corticospinal tract
66
Is the basal ganglia a grey or white matter structure?
grey
67
Name the 5 components of the basal ganglia
```
caudate nucleus
putamen
globus pallidus
subthalamic nucleus
substantia nigra
```
68
Name the components of the striatum
caudate nucleus, putamen
69
Name the components of the corpus striatum
caudate nucleus, putamen, globus pallidus
70
Name the components of the lenticular nucleus
putamen, globus pallidus
71
Is the internal capsule a grey or white matter structure?
white
72
What is the function of the internal capsule?
Connects cerebellar hemispheres
73
What is the function of the direct pathway of the basal ganglia?
increases thalamus outflow to enhance movement
74
What is the function of the indirect pathway of the basal ganglia?
inhibits thalamus outflow to stop unwanted movement
75
Describe the main function and appearance of the substantia nigra?
dark streak in brainstem
| produces dopamine
76
does the basal ganglia control ipsilaterally or contralaterally?
contralaterally
77
changed muscle tone, dyskinesia, tremor, chorea and myoclonus could all arise due to a lesion in the ______
basal ganglia
78
what structure produces CSF
choroid plexus of the ventricles
79
how much CSF is produced/absorbed a day
a pint
80
what structures does the cerebral aqueduct connect?
3rd and 4th ventricle
81
what structures does the interventricular foraminae of Monroe connect
3rd to lateral ventricles
82
dendrites convey graded electrical signals ____ to the neuron soma
passively
83
what part of a neuron contains the nucleus
body aka soma
84
neurons coma in different shapes; unipolar, pseudounipolar, bipolar and multipolar. what shape is a retinal neuron?
bipolar
85
neurons coma in different shapes; unipolar, pseudounipolar, bipolar and multipolar. what shape is a DRG?
pseudounipolar
86
neurons coma in different shapes; unipolar, pseudounipolar, bipolar and multipolar. what shape is a LMN?
multipolar
87
What is the most numerous cell type in the CNS?
glial cells
88
Name the 4 major types of glial cell
astrocytes
oligodendrocytes/Schwann cells
microglia
ependymal cells
89
There is no connective tissue in the CNS, what cell type instead takes on this role?
astrocytes
90
What is the shape of an astrocyte
a star
91
Name 3 of the roles of an astrocyte
blood brain barrier
homeostasis
support
92
Name the cells that produce myelin
oligodendrocyte in CNS
| Schwann cell in PNS
93
Describe how the appearance of schwann cells and oligodendrocytes differs
oligodendrocytes have multiple branches attaching to multiple axons, whereas there is only 1 schwann cell for every segment of each axon
94
Name the gap in the myelin sheath of a nerve, between adjacent schwann cells
node of ranvier
95
What is the function of myelin sheaths and rodes of ranvier?
increase conduction velocity
96
What cell type are microglia derivates of?
macrophages
97
What is the function of microglia?
immune monitoring, antigen presentation
98
What is the function of ependymal cells
form the epithelium lining the ventricles
99
Ependymal cells are ciliated. true or false?
true
100
Where is white matter found in the brain?
deep to the layer of outer grey matter
101
____ matter is composed of cells processes, synapses, glial cells, neuron soma and blood vessels
Grey matter
102
____ matter is composed of myelinated axons + glial cells + blood vessels
white matter
103
what level does the spinal cord end
L1/2
104
name the structure in the spinal cord that contains CSF
central canal
105
what is the function of the lumbar enlargement of the spinal cord at L1-3?
lower limb innervation
106
what is the function of the cervical enlargement of the spinal cord at C3-T1?
upper limb innervation
107
what is the name of the additional grey matter structure in the spinal cord present at T1-L2 and what is its function
lateral horn
| contains preganglionic sympathetic neurons
108
name the grey matter horns of the spinal cord, and what is their basic function
dorsal sensory horn
| ventral motor horns
109
what is the other name for the white matter columns of the spinal cord
fasciculi
110
what are the names of the white matter columns of the spinal cord
dorsal
lateral
ventral
111
what is the name of the structure that contains the epidural venous plexuses + adipose and is found between dura and vertebrae
epidural space
112
the spinal nerves commence the start of the ___
PNS
113
the posterior rami of spinal nerves supply the _____
back of neck/trunk
114
the anterior rami of spinal nerves supply the _____
limbs, anterior/lateral trunk
115
what is the name of the thin piece of connective tissue that is a continuation of the conus medullaris ?
filum terminale
116
what is the name of the structure that attaches the lateral SC to the dura to suspect the SC with the spinal canal
denticulate ligament
117
how many neurons are there in the somatosensory pathway
3
118
where is the cell body of the 1st neuron (the primary sensory afferent) in the somatosensory pathway
in dorsal root ganglia or cranial ganglia
119
where is the cell body of the 2nd neuron in the somatosensory pathway
dorsal horn of spinal cord or in brainstem
120
where is the cell body of the 3rd neuron in the somatosensory pathway
thalamus
121
is a stretch receptor a slow or fast sensory unit?
slow
122
is a muscle spinal a slow or fast sensory unit
fast
123
is a Pacinian corpuscle a slow or fast sensory unit?
very fast
124
'the site innervated by 1 sensory unit' is the definition of ____??
receptive field
125
what can be used to measure receptive field
2 point discrimination
126
'the afferent ending of 1 sensory axon' is the definition of ____???
sensory unit
127
itch, pain, temp, proprioception and pressure are examples of sensory ____
itch, pain, temp, proprioception and pressure are examples of sensory modalities
128
____ stimuli have a low threshold for sending a signal in the somatosensory pathway
innocuous
129
nociceptors are ___ threshold receptors for initiating a signal
high threshold
130
receptive field size varies with body part. true or false
true
131
pacinian and meissner's corpuscles are found on hairy skin. true or false
false
| pacinian corpuscles are found on hairy skin, meissner's corpusclesare found on hairless skin
132
the dorsal column medial lemniscus pathway innervates the whole body. true or false
false, doesn't innervate anterior head
133
what sensory modalities does the dorsal column medial lemniscus pathway deal with
fine touch and conscious proprioception
134
where does the dorsal column medial lemniscus pathway synapse and decussate
medulla
135
the fasciculus cuneatus of the DCML pathway innervates _____
everything above T6 (except anterior face)
136
the fasciculus gracilis of the DCML pathway innervates _____
below T6
137
what modalities does the spinothalamic tract deal with
pain and temperature
138
where does the spinothalamic tract decussate and synapse?
at level they enter dorsal horn of the spinal cord
139
the ____ tract conveys unconscious proprioceptive info to the cerebellum to guide posture and limb movements
spinocerebellar tract
140
the trigeminal system is responsible for sensory innervation of the anterior head, where are the soma of the trigeminal system located?
trigeminal sensory ganglion
141
in somatosensation, lateral inhibition modifies information via _____ on the way to the primary somatosensory cortex
inhibitory interneurons
142
"an alpha motor neuron and all the fibres it innervates" is the definition of _____?
motor unit
143
name the two types of LMNs
α alpha motor neuron
| γ gamma motor neuron
144
what do alpha motor neurons innervate?
extrafusal fibres of skeletal muscle
145
what to gamma motor neurons innervate?
muscle spindle intrafusal fibres
146
type I skeletal muscle fibres get ATP from ______ and are fatigue ____
ATP from oxidative phosphorylation, fatigue resistant
147
type ____ skeletal muscle fibres get ATP from glycolysis, not fatigue resistant
IIb fast
148
are muscle spindles in extensors or flexors?
extensors
149
muscle spindles are monosynpatic. true or false
true
150
"the αMNs that innervate a single muscle" is the definition of the ______??
motor neuron pool
151
the _____ regulate muscle tension to prevent overload
golgi tendon organs
152
the ____ reflex is where a muscle spindle registers a change in the length of skeletal muscle & opposes it
myotatic
153
the corticospinal CST tract is also know as the ____ tract
pyramidal
154
85% of fibres in the corticospinal tract cross at the _____ and the other 15% of fibres cross at the ____
85% of fibres in the corticospinal tract cross at the decussation of the pyramids and the other 15% of fibres remain uncrossed
155
the crossed ____ fibres in the CST are responsible for _____
the crossed lateral fibres in the CST are responsible for fine movements of the distal limb
156
the uncrossed ___ fibres in the CST are responsible for movements of ____ body parts
the uncrossed ventral fibres in the CST are responsible for movements of proximal/axial body parts
157
the corticobulbar pyramidal tract contains the CN UMNs for motor innervation to the ______
face, head and neck
158
motor system outside the pyramidal tract are referred to as the ______ system
extrapyramidal system
159
name the 4 tracts that make up the extrapyramidal system
rubrospinal
vestibulospinal
reticulospinal
tectospinal
160
which extrapyramidal tract originates the red nucleus of the midbrain
rubrospinal
161
what is the function of the rubrospinal tract
excite flexors & inhibit extensors of the upper body
162
what is the function of the vestibulospinal tract?
posture/antigravity muscles; leg extensors/arm flexors
163
what is the function of the tectospinal tract?
reflex head movement to visual/auditory stimuli
164
the reticulospinal tract has two divisions, what are their names
lateral medullary and medial pontine
165
what is the name of the nerve involved and the spinal cord level of the biceps reflex?
C5/6 musculocutaneous
166
what is the name of the nerve involved and the spinal cord level of the triceps reflex?
C7/8 radial
167
what is the name of the nerve involved and the spinal cord level of the knee jerk reflex?
L3/4 femoral
168
what is the name of the nerve involved and the spinal cord level of the ankle jerk reflex?
S1/2 tibial
169
the ____ separates scala media and the scala tympani
basilar membrane
170
in the auditory pathway, where do the hair cells synapse
spiral ganglion
171
go and learn the auditory pathway.
```
spiral ganglion>
cochlear nerve>
ventral cochlear nucleus>
dorsal cochlear nucleus>
project bilaterally> superior olivary nucleus>
lateral lemniscus>
inferior colliculus>
medial geniculate body>
primary auditory cortex in superior temporal gyrus
```
172
in the vestibular system, what is are the semicircular canals responsible for
rotational movement
173
name the otolith organs
urticle and saccule
174
in the vestibular system, what are the otolith organs responsible for
tilt, acceleration, gravity
175
in the vestibular system, the cupula is displaced by _____ movement
endolymph
176
in the vestibular system, the ___ contains the crista, hair cells and cupula
ampulla
177
the ____ reflex keeps the eyes fixed when the head moves
vestibulocular
178
the ___ hair cells are afferent CN VII
inner
179
the ___ hair cells are efferents from the superior olivary nucleus
outer
180
in the visual system, what is the function of lateral inhibition
aids localization and contrast
181
in the visual pathway, after fibres cross at the optic pathway where do they go next
optic tract
182
in the visual pathway, where do fibres go after the optic tract
optic radiation
183
where is the optic radiation located
superior in parietal lobe, inferior in temporal lobe
184
in the visual pathway, where do fibres go after the optic radiation
visual cortex
185
meyer's loop is part of the ______ that loops around the temporal lobe, it contains _____ visual field fibres
meyer's loop is part of the inferior optic radiation that loops around the temporal lobe, it contains upper visual field fibres
186
what is the resting membrane potential of a neuron
-70
187
what is the threshold membrane potential for an action potential in a neuron
-60
188
in a neuron action potential, what happens on the upstroke
depolarisation: voltage gated Na channels open
189
in a neuron action potential, what happens on the downstroke
hyperpolarisation: voltage activated K channels open
190
the ______ separates the pre and post-synaptic membrane
synaptic cleft
191
at the termination of a synapse ______ enzyme degrades ACH to ____ and _____
at the termination of a synapse acetylcholinesterase enzyme degrades ACH to acetate and choline
192
does excitation happen during depolarisation or hyperpolarisation?
depolarisation
193
ionotropic receptors are rapid and metabotropic receptors are slow at signalling. true or false
true
194
give an example of an ionotropic receptor
ACh nicotinic receptor
195
give an example of a metabotropic receptor
ACh muscarinic GPCR
196
what is the main excitatory transmitter
glutamate
197
what receptors does glutamate act on
ionotropic NMDA glutamate receptors and ionotropic non-NMDA glutamate receptors
198
glutamate binding to its receptor triggers a depolarising ____
EPSP excitatory postsynaptic potential
199
glutamate binding to its receptor triggers a depolarising EPSP, does this always result in an action potential?
no, only if the depolarisation reaches the threshold
200
what is the main inhibitory transmitter
GABA
201
what receptors does GABA act on
ionotropic GABA-A or metabotropic GABA-B receptor
202
what ion is involved ionotropic GABA-A receptors?
Cl
203
what ion is involved metabotropic GABA-B receptors?
K
204
GABA binding to its receptor triggers a hyperpolarising ____
IPSP inhibitory post synaptic potential
205
what is the function of a IPSP
inhibits action potentials
206
is glycine an inhibitory or excitatory transmitter?
inhibitory
207
GABA and glycine are both widespread inhibitory neurotransmitters. true or false
false. GABA is widespread but glycine is only found in the brainstem and spinal cord
208
what type of neuron is glycine involved iwth in the spinal cord?
inhibitory internuerons
209
what type of neurotransmitter are GABA, glycine and glutamate?
amino acid transmitter
210
what type of neurotransmitter are dopamine, histamine, NA and serotonin?
amine transmitters
211
______ type of pain is adaptive and immediate
nociceptive
212
______ type of pain is adaptive and functions for healing
inflammatory
213
_____ type of pain is a maladaptive
pathological
214
what type of stimuli activate nociceptor Aδ fibres
mechanical and thermal
215
what type of stimuli activate nociceptor C-fibres
all
216
how is pain from nociceptor Aδ fibres experienced?
first quick stabbing / pricking feeling
217
how is pain from nociceptor C fibres experienced?
2nd slow burn, throb, cramp, ache
218
are nociceptor Aδ fibres myelinated?
thinly melinated
219
are nociceptor C fibres myelinated?
unmyelinated
220
name the subset of nociceptive C fibres that release pro-neurogenic-inflammation mediators
peptidergic polymodal
221
where are the soma of neurons in the nociceptive pathway located
trigeminal ganglion or dorsal root ganglion
222
what horn of the spinal cord contains nociceptive fibres
dorsal horn
223
name the tract that carries fast Aδ nociceptive fibres to the thalamus
spinothalamic
224
name the tract that carries slow C nociceptive fibres to the brainstem
spinoreticular
225
[somatic/visceral] pain is from body wall structures eg. the peritoneum
somatic
226
is somatic or visceral pain well localised
somatic
227
is somatic or visceral pain experienced as a dull ache / throbbing sensation
visceral
228
What word is used to describe the organisation of the primary somatosensory cortex and primary motor cortex
somatotopic
229
What part of the body makes up the biggest portion of the sensory cortical homunculus and the motor cortical homunculus
hands
230
How do you recognise the pons on histology sections?
horizontal bands
231
How do you recognise the midbrain on histology sections?
contains the cerebral aqueduct
232
In the corticospinal tract, where do fibres go after the medulla?
through pons, then midbrain, then internal capsule, then to primary motor cortex
except reverse?
233
The prosencephalon (one of the primary vesicles of the brain in development) splits to give rise to 2 secondary vesicles, what are their names?
telencephalon
| diencephalon
234
What structure in the mature brain does the telencephalon become?
the cerebral hemispheres
235
What structure in the mature brain does the mesencephalon become?
midbrain
236
The rhombencephalon (one of the primary vesicles of the brain in development) splits to give rise to 2 secondary vesicles, what are their names?
metencephalon
| mylencephalon
237
What structure in the mature brain does the metencephalon become?
pons, cerebellum
238
What structure in the mature brain does the mylencephalon become?
medulla
239
Which primary vesicles form the forebrain, midbrain and hindbrain?
```
forebrain = prosencephalon
midbrain = mesencephalon
hindbrain = rhombencephalon
```
