Nervous anatomy and physiology Flashcards
(232 cards)
1
Q
Tonic labyrinthine reflexes
A
Keep the axis of the head in relationship with the rest of the body
Uses information from maculae and neck proprioceptors
2
Q
Dynamic righting reflexes
A
Stop you falling when you trip
Most profound in cats
3
Q
Static reflex
A
When you tilt your head, the eyes intort/ extort to compensate
A vestibulo-occular reflex
4
Q
In the PNS, the myelin sheath is formed by…
A
Schwann cells
5
Q
In the CNS, the myelin sheath is formed by…
A
Oligodendrocytes
6
Q
Collections of neuronal cell bodies, buried within the white matter of the brain are called…
A
Basal ganglia
7
Q
The collection of white matter tracts through which the hemispheres communicate with each other is called…
A
Corpus callosum
8
Q
Internal lobe, between the frontal and temporal lobes is called…
A
The insula
9
Q
Area 4 (function and location)
A
Primary motor cortex: motor homunculus
precentral gyrus
10
Q
Area 44, 45
function and location
A
Broca’s area of motor speech
inferior frontal gyrus
11
Q
Area controlling cognitive functions of higher order-intellect, judgement, prediction, planning
A
Prefrontal cortex
12
Q
Areas 3, 1, 2
function and location
A
Primary sensory area: sensory homunculus
post central gyrus
13
Q
Area of the brain responsible for interpretation of general sensory info and conscious awareness of opposite half of body
A
Superior parietal lobule
14
Q
Area of the brain which is the interface between somatosensory cortex and visual + auditory association areas
A
Inferior parietal lobule/ global association area
*In dominant hemisphere, contributes to language functions
15
Q
Areas 41, 42
A
Primary auditory cortex
superior temporal gyrus
16
Q
Location of the auditory association area
A
Posterior to areas 41, 42
In the dominant hemisphere the auditory association area is Wernicke’s area
17
Q
Area of the brain responsible for the conscious appreciation of smell
A
Inferior surface of the temporal lobe
Receives fibres from the olfactory tract
18
Q
Area 17 (function and location)
A
Primary visual cortex
medial surface of the occipital lobe, either side of the calcarine sulcus
19
Q
Area of the brain involved in memory and the emotional aspects of behaviour
A
Limbic lobe (a functional area)
20
Q
Contents of the limbic lobe
A
Cingulate gyrus
Hippocampus
Hypothalamus
Amygdala
21
Q
Location of the hippocampus
A
Medial aspect of temporal lobe
22
Q
Function of Broca’s area
A
Motor speech
23
Q
Wernicke’s area
function and location
A
The auditory association area in the dominant hemisphere
Necessary for recognition of spoken word
24
Q
Aphasia
A
Problems with speech due to damage of one or more speech areas in the brain
25
Myelinated axon fibres connecting corresponding areas of the two hemispheres together are called...
Commisural fibres
26
Myelinated axon fibres connecting one part of the cortex with another are called...
Association fibres
| may be short or long
27
Myelinated axon fibres running between the cerebral cortex and various subcortical centres (below), passing through the internal capsule are called...
projection fibres
28
The narrow area between the thalamus and the caudate/lentiform nuclei, made up of projection fibres passing to and from the cerebral cortex
The internal capsule
29
Blood supply of the internal capsule
Middle cerebral artery
| so is frequently affected in a stroke
30
Tract carrying motor impulses from cortex to skeletal muscles
Corticospinal/ pyramidal
31
Tract carrying sensory information (other than pain and temperature)
Posterior/ dorsal column
32
Tract carrying pain and temperature sensory information
Lateral spinothalamic tract
33
Fibres of the corticospinal tract synapse...
In the ventral horn
34
The corticospinal tract decussates...
At the decussation of the pyramids in the inferior medulla
35
No. of neurons making up the motor pathway
2:
UMN
LMN
(synapse in the ventral horn at the level where they exit)
36
The posterior/dorsal column decussates...
In the medulla
37
After decussation, the posterior/dorsal column is called...
The medial lemniscus
38
The lateral spinothalamic tract decussates...
At the level of entry
39
For ascending spinal tracts, which order neuron decussates?
2nd order neuron
40
Effect of an UMN lesion on tone...
Spasticity
| Increased tone
41
Effect of a LMN lesion on tone...
Flaccidity
| Decreased tone
42
Effect of a LMN lesion on reflexes
Areflexia
| absent reflexes
43
Effect of an UMN lesion on reflexes
Hyper-reflexia
| Exaggerated reflexes
44
EEG
ElectroEncephaloGram
Records activity of underlying neurons
45
Circadian rhythm
A biological system showing oscillations of ~24hrs
Demonstrated by the SCN (suprachiasmatic nuclei) of the hypothalamus - the "master clock"
46
Result of UMN lesion above the decussation
Contralateral spastic paralysis and hyperreflexia
47
Result of UMN lesion below the level of decussation
Ipsilateral spastic paralysis and hyperreflexia
48
Result of LMN lesion
Ipsilateral flaccid paralysis and areflexia
49
Melatonin is released by ……………… stimulated by ……………..
Melatonin is released from the pineal gland, stimulated by activity in the SCN (Suprachiasmatic nuclei) of the hypothalamus
50
Feeling of sleepiness is produced by which hormone?
Melatonin
51
The neurotransmitter required for wakefulness is called...
Orexin
52
On an EEG recording, frequency increases with...
Neuronal excitation
E.g.
anaesthesia --> sleep --> awake --> epilepsy
53
On an EEG recording, amplitude increases with...
decreasing neuronal excitation
54
Cognition definition
The integration of all sensory information to make sense of a situation
55
Function of the hippocampus (in learning and memory)
Formation of memories
56
Function of the cortex (in learning and memory)
Storage of memories
57
Function of the thalamus (in learning and memory)
Searches and accesses memories
58
The limbic system is responsible for what types of behaviour?
Instinctive (thirst, hunger, sex etc.)
Emotive (driven by reward/ punishment) - gives emotional significance to events, essential for memory
59
The ability to hold experiences in the mind for a few seconds. Based on different sensory modalities
Immediate/ sensory memory
60
Type of memory associated with reverberating circuits
Short term memory,
Often called working memory
Used for tasks such as dialling a phone number
61
Type of memory associated with chemical adaptation at the presynaptic terminal
Intermediate long-term memory
Used to remember what you did last weekend etc...
62
Type of memory associated with structural changes in synaptic connections
Long-term memory
Used to remember childhood friends etc...
63
Anterograde amnesia
Cannot form new memories
Can be short lived or permanent following an injury
64
Retrograde amnesia
Cannot access (more recent) old memories
Occurs if thalamus damaged
65
Changes in structure in long-term memory
1. increase in number of presynaptic terminals
2. increase of neurotransmitter release sites
3. increase of neurotransmitter vesicles stored and released
66
Types of long term memory
Declarative/Explicit: for events, rules and language (relies heavily on hippocampus)
Procedural/Reflexive/Implicit: for acquired motor skills (independent of hippocampus)
67
Conversion of short-term memories to long-term memories
| definition and mechanism
Consolidation
Strengthening of synaptic connections through repetition
68
Which cranial nerves emerge from the pontomedullary junction
VI, VII, VIII
69
Function of the olive
Contains the inferior olivary nucleus
70
What structure does the "open" part of the medulla open onto?
What part of the medulla is this?
The 4th ventricle
The posterior, superior medulla
71
The "closed" part of the medulla is a continuation of what structure?
What part of the medulla is this?
The central canal of the spinal cord
The posterior, inferior medulla
72
Function of the cerebellar peduncles
Attach the cerebellum to the brainstem
73
Attachments of the middle cerebellar peduncle
Cerebellum
| Pons
74
The surface projections visible of the surface of the hypothalamus are called...
The mammillary bodies
75
The midline structure connecting the two cerebellar hemispheres is called...
The vermis
76
The ventricular space lying immediately anterior to the cerebellum is the...
4th ventricle
77
The part of the cerebellum above the foramen magnum...
The cerebellar tonsil
78
In a sudden drop in intracranial pressure, the cerebellar tonsils may herniate through the foramen magnum, this is called...
Cerebellar coning
79
The fissure separating the two cerebral hemispheres is called…
The medial longitudinal fissure
80
The structure connecting the two cerebral hemispheres is called the...
Corpus callosum
| composed of commissural fibres
81
The fold of dura mater separating the cerebellum from the cerebral hemispheres is called...
Tentorium cerebelli
82
At what level does the spinal cord terminate in an adult?
L1-2
83
At what level does the spinal cord terminate in a new-born?
L2-3
84
At what vertebral level does the dura mater terminate
S2
85
At what vertebral level does the arachnoid mater terminate?
S2
86
Fate of the pia mater, inferior to the spinal cord...
Becomes the filum terminalis
87
What occupies the space btw the termination of the spinal cord and the dura/arachnoid mater?
Conus medularis and cauda equina (spinal nerve roots L2 -Cc1)
88
Correct vertebral level of a lumbar puncture on an adult
Between L3 - 4 (with adult in a foetal position)
89
How many pairs of spinal nerves are there?
31
```
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
```
90
From which arteries do the left and right vertebral arteries arise?
Subclavian
91
Vertebral level of bifurcation of the common carotid artery
C3/4
92
Which part of the brainstem does the basilar artery overlie?
Pons
93
The anterior cerebral artery travels in which fissure of the brain?
Great longitudinal fissure
| follows the dorsal curvature of the corpus callosum
94
The middle cerebral artery travels within which fissure of the brain?
Lateral fissure
95
The posterior cerebral artery travels within which fissure of the brain?
Calcarine fissure
96
Blood supply of the primary motor cortex
```
Mainly middle cerebral artery
Medial aspect (lower limb area) by anterior cerebral artery
```
97
Blood supply to the primary sensory cortex
```
Mainly middle cerebral artery
Medial aspect (lower limb area) by anterior cerebral artery
```
98
Blood supply to primary visual cortex
Posterior cerebral artery
99
Blood supply to primary auditory area
Middle cerebral artery
100
Blood supply to area for olfaction in the brain
Middle cerebral artery
101
Areas of the brain supplied by the anterior cerebral artery
Medial surface of frontal and parietal lobes
102
Areas of the brain supplied by the middle cerebral artery
Lateral surface of frontal, parietal and temporal lobes
103
Areas of the brain supplied by the posterior cerebral artery
Occipital lobe
| Inferomedial aspect of temporal lobe
104
```
Carotid sinus
(function and pathway of sensory nerves)
```
Pressure receptor, monitors flow of blood to the head
Sensory nerves from it run in the glossopharyngeal and vagus nerves
105
```
Carotid body
(function and pathway of sensory nerves)
```
Contains chemoreceptors sensitive to anoxia
| Sensory nerves from it run in the glossopharyngeal nerve
detection of anoxia = ↑HR, RR, BP
106
The dilatation located in the terminal common carotid artery/proximal ICA is called...
The carotid sinus
107
The area on the posterior wall of the terminal common carotid artery is called...
The carotid body
108
The dural venous sinuses draining the brain are located between which layers inside the skull?
Between the periosteum and cranial dura
109
The dural venous sinuses drain into...
IJV
110
What veins drain into the cavernous sinus?
Superior ophthalmic veins
| potential route of infection from extra to intracranial
111
Why is the brain at risk of infection through venous routes?
Veins in the brain and venous sinuses do not have valves to prevent backflow from outside to inside the cranium
112
Bony attachments of the falx cerebri
Crista gali
| Internal occipital protuberance
113
Bony attachments of the anterior edge of the tentorium cerebelli
Anterior clinoid processes
114
Which dural sinus runs along the attachment of the falx cerebri to the tenrorium cerebelli?
Straight sinus
115
The dural fold separating the cerebellar hemispheres is called...
Falx cerebella
116
The fold of dura mater surrounding the pituitary stalk is called...
The sellar diaphragm
117
The middle meningeal artery is a branch of which artery?
The maxillary artery
118
The middle meningeal artery supplies...
The dura mater
119
The anterior horn of the lateral ventricle lies within which lobe?
Frontal lobe
120
The body of the lateral ventricle lies within which lobe?
Parietal lobe
121
The posterior horn of the lateral ventricle lies within which lobe?
Occipital lobe
122
The inferior horn of the lateral ventricle lies within which lobe?
Temporal lobe
123
The lateral ventricles are connected to the 3rd ventricle by the...
Interventricular foramen/ foramen of Monro
124
Location of the 3rd ventricle
In the diencephalon
125
Location of the 4th ventricle...
Btw the brainstem and the cerebellum
126
What structure absorbs CSF back into the general circulation?
Arachnoid villi in the sagittal sinus
127
Function of gamma motoneurons
Innervate the contractile ends of intrafusal muscle in the muscle spindle
This stretches the central area of the intrafusal fibres = fewer APs fired
128
When do gamma motoneurons fire?
| and why
With alpha motoneurons so the spindle shortens with the muscle so can keep transmitting sensory info
129
What increases/ decreases muscle spindle discharge of APs?
Muscle contracts = spindle stretched = ↓ APs
Muscle relaxes/stretched = spindle relaxes = ↑ APs
130
What increases/ decreases GTO discharge of APs?
Muscle contracts = ↑tension in GTO = ↑APs
Muscle relaxes = ↓tension in GTO = ↓APs
131
3 results of the stretch reflex
1. agonist contracts (monosynaptic reflex)
2. antagonist relaxes (activation of inhibitory interneurons - reciprocal inhibition)
3. sensory info ascends in dorsal column
132
3 results of the inverse stretch reflex/ GTO reflex/ clasp knife reflex
1. agonist relaxes (activation of inhibitory interneurons)
2. antagonist contracts (activation of excitatory interneurons)
3. sensory info ascends in dorsal columns
133
Function of the Golgi tendon organ
Monitors muscle tension
134
Function of the muscle spindle
Monitors muscle length
135
3 results of the flexor-withdrawal reflex
1. ipsilateral flexion*
2. contralateral extension*
3. info ascends in the spinothalamic tract
*through stimulation of excitatory/inhibitory interneurons
136
The middle cerebellar peduncle is made up of...
Motor nerve fibres
137
The cerebral peduncles are made up of...
Sensory and motor fibres
138
The vertebral and basilar arteries (vertebro-basilar system) supply
Brainstem
Occipital lobes
Cerebellum
139
Pain occurring when specific peripheral sensory neurons respond to noxious stimuli
Nociceptive pain
Pain usually localised to site of injury
Usually responds to conventional analgesics
140
Pain initiated/caused by a primary lesion in the somato-sensory nervous system
Neuropathic pain
141
Aα and Aβ fibres
| structure and function
Large diameter, myelinated
Proprioception, light touch
142
Aδ fibres
| structure and function
Medium diameter, lightly myelinated
Nociception (fast pain)
143
```
C fibres
(structure and function)
```
Small diameter, unmyelinated
Non-noxious temperature
Itch
Nociception (slow pain)
144
Exaggerated response to noxious and non-noxious stimuli (increased perception of pain)
(name and when it occurs)
Hyperalgesia
Occurs with tissue injury and inflammation (inflammatory mediators cause nociceptor changes)
145
Decreased threshold for nociceptor response (non-noxious stimuli perceived as pain) is called...
Allodynia
| occurs centrally as a clinical feature of many conditions
146
An injury caused by a blunt force is called...
A laceration
147
An injury caused by a sharp object is called...
An incised wound
148
Fracturing of the orbital plates caused by a fall onto the back of the head...
Contre-coup fracture
149
Fracture encircling the foramen magnum caused by a fall from height, leading to the skull base and cervical spine being forced together...
Ring fracture
150
How does increased ICP cause death?
Compression of the brainstem due to herniation of the cerebellar tonsils into foramen
magnum
151
Main cause of extradural haemorrhage...
Damage to an artery with skull fracture (often MMA)
| arterial bleeding = high pressure
152
A lucid interval in which a patient seems ok following a head injury then deteriorates catastrophically later is often due to...
Extradural haemorrhage
May be seen with subdural haemorrhage
153
Mot common cause of subdural haemorrhage...
Trauma without a fracture
Relative movement between brain and dura causes veins to stretch and tear (bleeding is from veins so accumulates slowly)
154
Most common cause of subarachnoid haemorrhage...
Rupture of a cerebral artery "berry" aneurysm
155
Commonest cause of traumatic basal subarachnoid haemorrhage (TBSAH)
Abrupt rotation of the head --> rupture of vertebra-basilar circulation
(death probably due to rotation of the brainstem at the same time)
156
Commonest cause of death in fatal head injuries
Cerebral oedema (rapid result of brain injury) --> brain swelling --> raised ICP + coning
157
Cerebral contusion
| meaning
Bruising to the brain
158
The thin sheet separating the lateral ventricles in the mid-sagittal plane is called...
Septum pellucidum
159
The bundle of fibres linking the hippocampus to the mamillary bodies is called...
The fornix
160
In what part of the brainstem is the substantia nigra
Midbrain
161
Location of the red nucleus
In the midbrain, posterior to the substantia nigra
162
What is the name of the hole in the middle of the spinal cord?
Central canal
163
Cranial nerves with a parasympathetic component
III, VII, IX, X
164
Origin of the oculomotor nerve
Midbrain
165
Origin of trochlear nerve
Posterior midbrain
166
Origin of trigeminal nerve
Pons
167
Origin of abducent nerve
pontomedullary junction
168
Origin of facial nerve
pontomedullary junction
169
Origin of vestibulocochlear nerve
pontomedullary junction
170
Origin of glossopharyngeal nerve
Medulla (lateral to olive)
171
Origin of vagus nerve
Medulla (lateral to olive)
172
Origin of accessory nerve
Medulla (lateral to olive)
| + spinal roots
173
Origin of hypoglossal nerve
Medulla (medial to olive)
174
Somatic motor actions of the trigeminal nerve (V3)
Muscles of mastication
Digastric
Tensor veli palatine
Tensor tympani
175
EEG waves when awake and alert
β waves
V. high frequency
Low amplitude
176
EEG waves when awake and relaxed
α waves
High frequency
High amplitude
177
EEG waves in stage 1 slow wave sleep
θ waves
Low frequency
High amplitude
178
EEG waves in stage 2 slow wave sleep
θ waves (low frequency, high amplitude) with sleep spindles
179
EEG waves in stage 3 slow wave sleep
δ waves (v. low frequency and high amplitude) with episodes of faster waves
180
EEG waves in stage 4 slow wave sleep
Exclusively δ waves
181
EEG waves in REM sleep
Mimic β waves
182
Fibres activating the pupillary reflex do not travel to the LGB but instead leave the optic tract to go to the...
EWN
(part of the 3rd nerve nucleus which is for parasympathetic fibres)
In the midbrain
183
Identifying a cervical spinal cord segment
| segment, ventral horn, dorsal horn
Segment: large and oval
Dorsal horn: Long and slender
Ventral horn: Broad and large
184
Identifying a thoracic spinal cord segment
| segment, ventral horn, dorsal horn
Segment: small and circular
Dorsal horn: slender
Ventral horn: slender
185
Identifying a lumbar spinal cord segment
| segment, ventral horn, dorsal horn
Segment: large and circular
Dorsal horn: Bulbous and short
Ventral horn: Bulbous and short
186
Identifying a sacral spinal cord segment
| segment, ventral horn, dorsal horn
Segment: small and circular/quadrilateral
dorsal horn: massive and ovoid
ventral horn: massive and ovoid
187
In rehabilitation, goals set should be...
```
S-pecific
M-easurable
A-cheivable
R-ealistic/relevant
T-imely
```
188
The role of lateral pathways in motor control
+ the control of these pathways
Control voluntary movements
Under direct CORTICAL control
189
The role of ventromedial pathways in motor control
+the control of these pathways
Control posture and locomotion
| Under BRAINSTEM control
voluntary/ ocular/ vestibular... etc. input
190
2 lateral pathways are...
Corticospinal tract
Rubrospinal tract
191
2 immediate functions of the corticospinal tract
1. monosynaptically excite pools of AGONIST motoneurones
| 2. inhibit ANTAGONIST motoneurones via interneurones
192
The ventromedial tract that stabilises the head and neck is called...
The vestibulospinal tract
193
The ventromedial tract that ensures the eyes remain stable as the body moves is called...
The tectospinal tract
194
The ventromedial tract that reflexly maintains balance and body position is called...
The pontine and medullary reticulospinal tracts
195
The pontine and medullary reticulospinal tracts innervate...
The trunk and anti-gravity muscles in the limbs
| to reflexly maintain body position and balance
196
Area 6
| + location
Premotor and supplementary motor areas
| anterior to the motor cortex - area 4
197
Basal ganglia making up the corpus striatum
Caudate nucleus
| Lentiform nucleus
198
Main sign of a cerebellar lesion
Ataxia
| fail to touch nose with eyes shut
199
Motor learning
| where it happens + what it is
Occurs in the cerebellum
Compares what is intended and what happened and compensates for next time
200
Aim of the direct pathway
To UN-inhibit the thalamus
| so it can excite the motor cortex - and you can move
201
Aim of the indirect pathway
To inhibit the thalamus
| so it is unable to excite the motor cortex - and you don't move
202
3 parts of the neural tube at 27 days
Prosencephalon (forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)
203
At 32 days, the prosencephalon forms the...
telencephalon
| diencephalon
204
At 32 days, the rhombencephalon forms the...
metencephalon
| myelencephalon
205
The telencephalon forms which adult structures
cerebral hemispheres
hippocampus
basal ganglia
206
The diencephalon forms which adult structures
Thalamus
hypothalamus
pituitary gland
pineal gland
207
the mesencephalon forms which adult structures
superior and inferior colliculi
208
the metencephalon forms which adult structures
cerebellum
| pons
209
The myelencephalon forms which adult structures
medulla
210
All CNS cells (neurons, astrocytes, oligodendrocytes, ependymal cells) except microglia develop from...
neuroepithelial cells (lining the neural tube)
211
Microglia develop from...
mesenchymal cells (which migrate into the CNS)
212
neural crest cells break away from the neural tube and migrate throughout the embryo forming...
```
ganglia
adrenal medulla
body pigment (except eyes)
branchial arches
sensory neurons
```
213
Structures derived from the 1st branchial arch are supplied by...
CrN. V3 (and V2)
so it forms:
- anterior belly of digastric
- mylohyoid
- malleus and incus
- tensor tympani
- mandible and maxilla
- tensor veli palatini
- muscles of mastication (pterygoids, masseter, temporalis)
214
Structures derived from the 2nd branchial arch are supplied by...
Facial nerve
so it forms:
- muscles of facial expression
- trapezius, sternocleidomastoid + platysma
- stapes + stapedius
- posterior belly of digastric
215
Structures derived from the 3rd branchial arch are supplied by...
glossopharyngeal nerve
so it forms:
- stylopharyngeus
216
Structures derived from the 4th branchial arch are supplied by...
Superior laryngeal branch of vagus
so it forms:
- cricothyroid muscle
217
Structures derived from the 6th branchial arch are supplied by...
Recurrent laryngeal branch or vagus
so it forms:
- intrinsic muscles of the larynx
218
pupillary light reaction afferent and efferent
```
afferent = II
efferent = III
```
219
corneal reflex afferent and efferent
```
afferent = V1
efferent = VII
```
220
Jaw jerk afferent and efferent
```
afferent = V
efferent = V
```
221
oculocephalic reflex afferent and efferent
"dolls eyes" - eyes stay looking at the same point when head is rotated before moving
```
afferent = VIII
efferent = III, IV, VI
```
222
Oculovestibular reflexes afferent and efferent
static reflex
dynamic vestibular nystagmus (COWS)
```
afferent = VIII
efferent = III, IV, VI
```
223
myotome C5
elbow flexors
224
myotome C6
wrist extensors
225
myotome C7
elbow extensors
226
myotome C8
finger extensors
227
myotome T1
intrinsic hand muscles
228
myotome L2
hip flexors
229
myotome L3
knee extensors
230
myotome L4
ankle dorsiflexors
231
myotome L5
long toe extensors
232
myotome S1
ankle plantar flexors
