Neuroanatomy Flashcards
(183 cards)
1
Q
What is the 8th cranial nerve? (VIII)
A
Vestibulocochlear nerve
2
Q
What is the 3rd cranial nerve? (III)
A
Oculomotor nerve
3
Q
What is the 5th cranial nerve? (V)
A
Trigeminal nerve
4
Q
What are the 3 branches of the trigeminal nerve?
A
Va = opthalmic Vb = maxillary Vc = mandibular
5
Q
Which cranial nerve is the hypoglossal nerve?
A
12th (XII)
6
Q
Which cranial nerve is Abducens?
A
6th (VI)
7
Q
Name the 12 cranial nerves in order
A
I = Olfactory II = Optic III = Oculomotor IV = Trochlear V = Trigeminal VI = Abducens VII = Facial VII = Vestibulocochlear IX = Glossopharyngeal X = Vagus XI = Accessory XII = Hypoglossal
8
Q
What broadmann number is the primary auditory area?
A
41
9
Q
What broadmann area number is the motor cortex?
A
4
10
Q
Wernicke’s, Broca’s and the primary auditory area are all involved in…..?
A
Speech/language processing
11
Q
What is the definition of areflexia?
A
Absence of reflexes
12
Q
What is the definition of apraxia?
A
Inability to perform accurate voluntary/skilled movements
13
Q
What is the definition of agnosia?
A
Inability to interpret sensory information
14
Q
At what level does the spinal cord terminate?
A
L1-L2
15
Q
In a baby, where may the spinal cord extend to?
A
3rd lumbar vertebrae
16
Q
Why may a T12 vertebral fracture paralyse the bladder/
A
Sympathetics innervating the internal urethral sphincter arise in T11-L2, which control constriction and relaxation of the sphincter
17
Q
What is the fornix?
A
A bundle of fibers connecting the hypothalamus and hippocampus.
18
Q
What is the corpus callosum?
A
A bundle of nerve fibres that connects the left and right hemispheres of the brain.
19
Q
If a patient could understand language but not speak in full sentences, which area may they have damaged?
A
Broca’s area (within frontal lobe premotor area)
20
Q
If a patient could speak with normal fluency but could not understand language, which area may they have damaged?
A
Wenicke’s area (within temporal lobe; sensory speech area)
21
Q
Where is the primary motor cortex located?
A
On the pre-central gyrus of the frontal lobe
22
Q
Where is the primary somatosensory cortex located?
A
On the post-central gyrus of the parietal lobe
23
Q
Where is the premotor cortex located?
A
Anterior to the primary motor cortex in the frontal lobe
24
Q
What does the premotor cortex do?
A
Recieves input from other motor areas of the cortex and deep nuclei and plans motor movements.
Communicates planned movements to the primary motor cortex.
25
Where is the visual cortex and what does it do?
On the most posterior aspect of the occipital lobe
Receives and interprets light information from the eyes for vision
26
Where is the auditory cortex and what does it do?
Located in the superior aspect of the temporal lobe.
Receives and interprets sound information from the ears for hearing.
27
Where is the vestibular cortex and what does it do?
Located on the temporal lobe (around the lateral fissure)
Receives and interprets vestibular information from the ears to control balance.
28
Where is the olfactory cortex and what does it do?
Located on the deep aspect of the temporal lobe.
Receives and interprets olfactory information from the nose for smell.
29
Where is the gustatory cortex and what does it do?
Located on inferior, posterior frontal lobe and deep to temporal lobe.
Receives and interprets gustatory information from the taste buds for taste.
30
Where is Broca's area?
Located within the inferior portion of the premotor area of the cortex (in frontal lobe) on the LEFT hemisphere.
31
Where is the frontal eye field and what does it do?
Located near the junction of the premotor cortex and the prefrontal cortex.
Receives input from the visual cortex and controls the voluntary movement of the eye muscles.
32
What is the Babinski reflex?
Reflex response of toes after sole of foot firmly stroked - big top moves upwards and other toes fan outwards.
Normal in children up to 2 years old.
33
What is the corticospinal tract also known as?
Pyramidal tract
34
What specifically are the components of the CNS?
Brain, spinal cord, retina and CN II
35
Name the 4 types of neuroglia in the CNS
1. Oligodendrocytes
2. Astrocytes
3. Ependymal cells
4. Microglia
36
Name the 2 types of neuroglia in the PNS
1. Satellite cells
| 2. Schwann cells
37
On what day of development does the cranial neuropore close?
Day 25
38
On what day of development does the caudal neuropore close?
Day 27
39
Which supplement prevents 70% of neural tube defects?
Folic acid
40
What are the 3 primary brain vesicles which the brain forms from?
1. Prosencephalon
2. Mesencephalon
3. Rhombencephalon
41
What are the 5 secondary brain vesicles and how are these divided?
1. Telencephalon
2. Diencephalon
(both from prosencephalon)
3. Mesencephalon
4. Metencephalon
5. Myelencephalon
(both from rhombencephalon)
42
What do the telencephalon and diencephalon form?
Cerebral hemispheres and thalamus/hypothalamus
43
What does the mesencephalon form?
Midbrain
44
What do the metencephalon and myelencephalon form?
Cerebellum and pons and medulla
45
What is the name of the line that separates the 2 cerebral hemispheres?
Longitudinal fissure
46
At the top of which lobe is the lateral fissure?
Temporal lobe
47
Which Broadmann area is the primary visual cortex?
17
48
Which Broadmann area is the pre-motor cortex?
6
49
What does the left side of the brain specifically look after? (4)
1. Bilateral audio
2. Speech
3. Writing
4. Language
50
What does the right side of the brain specifically look after? (3)
1. Bilateral audio
2. Spatial perception
3. Facial recognition
51
What are the putamen and globus pallidus collectively known as?
Lentiform nucleus
52
What are the components of the striatum?
Caudate and putamen
53
Where do commisural fibres connect?
Connect between hemispheres
54
Where do association fibres connect?
Connect within a hemisphere
55
Which two major blood vessels supply the brain and brainstem?
1. Internal carotid arteries
| 2. Vertebral arteries
56
The dura is 2 layers thick - name these layers?
1. Periosteal layer
2. Meningeal layer
Stuck together except for where there are dural venous sinuses running between them
57
What are the 3 meningeal layers covering the CNS (in order)?
1. Dura
2. Arachnoid
3. Pia
58
What can blockage of a venous sinus result in?
Cerebral infarction
59
What is the falx cerebri and what does it prevent?
Double layer of dura which prevents the left and right cerebral hemispheres from moving excessively during axial head rotation
60
What is the falx cerebelli and what does it prevent?
Double fold of dura which prevents left and right cerebellar hemispheres from moving excessively during axial rotation
61
What is the tentorium cerebelli and what does it prevent?
Double fold of dura which prevents the occipital lobe compressing the cerebellum during neck/head flexion and extension.
62
What is a choroid plexus?
Network of blood vessels in each ventricle in the brain, producing CSF.
63
What do muscle spindles detect?
Stretch
64
What type of sensation do Meissner Corpuscles detect?
Discriminative touch
65
What type of sensation do Pacinian corpuscles detect?
Deep pressure and vibration
66
What do ruffini endings detect?
Touch, Sheer stress/forces
67
What do Merkel Discs detect?
Light, sustained touch
68
What to free nerve endings detect?
Pain and temperature
69
Are temperature receptors rapidly or slowly adapting?
Rapid
70
Define somatotopy
The point-for-point correspondance of an area of the body to a specific point on the CNS
71
What is the internal capsule?
A bundle of white matter axons consisting of projecting fibres which pass to and from the cerebral cortex.
72
What are the 3 types of interconnection fibres in the cortex?
1. Projecting fibres (to brainstem/spinal cord)
2. Commisural fibres (between hemispheres)
3. Association fibres (within a hemisphere)
73
Name the 4 parts of the internal capsule
1. Anterior limb
2. Genu
3. Posterior limb
4. Retrolenticular (sits behind lentiform nucleus)
74
How many neurons are normally in the chain of sensory tracts? Name them?
3
1st order neurons
2nd order neurons
3rd order neurons
75
What do the 1st order neurons do (sensory)?
Ascend the spinal cord ipsilaterally so to nuclei in lower medulla
76
What do 2nd order neurons do (sensory)?
Decussate and ascend to the thalamus via a tract known as a lemiscus
77
What do 3rd order neurons do (sensory)?
Ascend to cortex from thalamus via internal capsule
78
What are the 2 main nuclei in the thalamus for somatosensory input?
1. Ventral posterior medial nucleus (VPM)
| 2. Ventral posterior lateral nucleus (VPL)
79
What does the ventral posterior lateral nucleus (VPL) recieve?
Sensory from limbs and trunk
80
What does the ventral posterior medial nucleus (VPM) recieve?
Sensory from face and most of the head
81
What are the names of the 3 funiculi which white matter can be grouped into in the spinal cord?
1. Dorsal funiculus
2. Lateral funiculus
3. Ventral funiculus
82
Describe a cervical section of the spinal cord
Large grey mater horns (due to large population of neurons required to innervate the upper limbs)
83
Describe a thoracic section of the spinal cord
Small grey horns
84
Describe a lumbar section of the spinal cord
Large grey horns (due to large population of neurons required to innervate the lower limbs)
85
Describe a sacral section of the spinal cord
Small white matter tracts (because very few white matter tracts at this level)
86
Name the 3 major ascending sensory pathways
1. Dorsal column pathway
2. Spinothalamic tract
3. Spinocerebellar tracts
87
What sensory information does the dorsal column pathway carry?
1. Discriminative touch
2. Vibration
3. Conscious proprioception
Meissner's, Merkel's Pacinian, Ruffini endings, Joint proprioceptors
88
What sensory information does the spinothalamic tract carry?
1. Pain and temperature
2. Simple touch
Free nerve endings
89
What sensory information do the spinocerebelalr tracts carry?
Unconscious proprioception
Muscle spindles and golgi tendon organs
90
What are the names of the 2 parts of the dorsal column pathway?
1. Fasciculus cuneatus (above T6)
| 2. Fasciculus gracilis (T6 and below)
91
At what level do 2nd order neurons of the dorsal column pathway decussate?
Lower medulla
92
How does sensory information from the face travel in the dorsal column pathway?
1st order trigeminal nerve sensory neurons enter the pons and synapse in the CN V nucleus.
2nd order neurons ascend in the trigeminal lemniscus to the VPM nucleus in the thalamus
3rd order neurons pass to the primary sensory cortex
93
Name some things which could damage a spinal column
- Compression
- Infarction
- Infection
- B12 deficiency (damages myelin sheath)
94
Where do neurons of the spinothalamic tract decussate?
1-2 vertebral levels above the entry of the 1st order neuron into the spinal cord
95
Where do 1st order neurons of the spinothalamic tract ascend before synapsing to 2nd order neurons?
In the Tract of Lissauer
96
What are the 2 divisions of the spinocerebellar tract?
1. Dorsal spinocerebellar tract (mainly via muscle spindles)
| 2. Ventral spinocerebellar tract (mainly via golgi tendon organs)
97
How many neurons in the spinocerebellar pathways?
2
98
Where does the oculomotor nerve originate?
Midbrain (oculomotor nucleus)
99
Where does the trochlear nerve originate?
Midbrain
100
Where does the trigeminal nerve originate?
Lateral pons
101
Where does the abducens nerve originate?
Ponto-medullary region
102
Where does the facial nerve originate?
Ponto-medullary region
103
Where does the vestibulo-cochlear nerve originate?
Ponto-medullary region
104
Where does the glossopharyngeal nerve originate?
Lateral medulla
105
Where does the vagus nerve originate?
Lateral medulla
106
Where does the accessory nerve originate?
Spinal cord C1-C5
107
Where does the hypoglossal nerve originate?
Ventral medulla
108
What does CN I do?
Sense of smell (sensory)
109
What does CN II do?
Sight (sensory)
110
What does CN III do?
Move eyeball, move eyelid, constrict the pupils (motor and parasympathetic)
111
What does CN IV do?
Moves eyeball (depression; superior oblique muscle) - motor
112
What does CN V do?
Sensory to the face, sinuses and teeth
| Motor to muscles of mastication (chewing)
113
What does CN VI do?
Moves eyeball (laterally; lateral rectus muscle) - Motor
114
What does CN VII do?
Facial expression,
taste to anterior 2/3 of tongue,
secretomotor of submandibular, sublingual and lacrimal glands
115
What does CN VIII do?
Hearing and balance (special sense)
116
What does CN IX do?
Motor: stylopharyngeus muscle
Sensory: Pharynx, chemo/baroreceptors from carotid body/sinus
Special sense: taste to posterior 1/3 tongue
Parasympathetic: parotid gland
117
What does CN X do?
Motor: muscles of palate, pharynx and larynx
Sensory: laryngopharynx, ear
Parasympathetic: heart, lungs, GI tract
118
What does CN XI do?
Motor to sternocleidomastoid and trapezius muscles (moves head and shoulders)
119
What does CN XII do?
Motor to all the muscles of the tongue for movement (except palatoglossus which is CN X)
120
What are the 5 main branches of the facial nerve?
1. Temporal
2. Zygomatic
3. Buccal
4. Marginal mandibular
5. Cervical
(To Zanzibar By Motor Car!)
121
Where does CN I exit the skull?
Cribriform plate
122
Where does CN II exit the skull?
Optic canal
123
Where deos CN III exit the skull?
Superior orbital fissure
124
Where does CN IV exit the skull?
Superior orbital fissure
125
Where does CN VI exit the skull?
Superior orbital fissure
126
Where does CN Va exit the skull?
Superior orbital fissure
127
Where does CN Vb exit the skull?
Foramen rotundum
128
Where deos CN Vc exit the skull?
Foramen ovale
129
Where does CN VII exit the skull?
Internal acoustic meatus
130
Where does CN VIII exit the skull?
Internal acoustic meatus
131
Where does CN IX exit the skull?
Jugular foramen
132
Where does CN X exit the skull?
Jugular foramen
133
Where does CN XI exit the skull?
Jugular foramen
134
Where does CN XII exit the skull?
Hypoglossal canal
135
What is the term for lack of smell?
Anosmia
136
What does the pupillary light reflex test?
Retina, CN II, midbrain and CN III
137
What is the normal response to the pupillary light reflex?
Shining light in one eye should make both pupils contract (consensual light reflex)
138
Which nuclei do neurons pass through in the pupillary light reflex?
CN II neurons send to pre-tactal nucleus (PTN)
This sends interneurons to Edinger-Westphal nucleus (EWN)
Pre-ganglionic parasympathetic fibres pass to ciliary ganglion
Post-ganglionic parasympathetic fibres pass to control sphincter pupillae
139
What is the name of the muscle controlled in the pupillary light reflex?
Sphincter pupillae
140
What does fundoscopy do?
Allows for examination of the retina/back of the eye
141
Which muscle does the CN IV control?
Superior oblique muscle
142
Which is the only cranial nerve to emerge from the dorsal side of the brainstem?
CN IV (Trochelar)
143
What does a lesion to CN IV cause?
Upward deviation and extorsion (outward rotation of the eye)
| Vertical diplopia: worse when looking down (e.g. going downstairs/reading)
144
What happens if there is a CN VI lesion?
No lateral movement of the eye so eye rests in adducted position (convergent squint)
Horizontal diplopia
Diplopia worse when looking towards the affected side
145
Why are UMN lesions hyper-reflexive?
In normal working reflexes, the reflex occurs within a LMN spinal cord 'loop'.
If the UMNs are not working to moderate these loops (via Renshaw Cells), then the reflex loops are in overdrive due to the LMNs working too well and the UMN not being able to moderate it.
146
Which gland does CN VII pass through?
Parotid gland
147
Which nerve innervates the parotid gland?
CN IX
148
Where is the geniculate ganglion of the facial nerve?
Collection of sensory cell bodies within the facial canal at the geniculum (bend in nerve).
149
What can injure CN VII?
Parotid gland surgery as the nerve passes through it
150
Why might the top half of the face (forehead) be spared in a CN VII lesion?
If it is an UMN lesion then the top half may be saved because it has bilateral innervation and therefore the unaffected side can continue to innervate it. If a LMN however, there will be full paralysis.
The lower half of the face has fibres from contralateral side only.
151
How is the vestibular portion of CN VIII tested?
Hallpike manoeuvre
| Positive test produces vertigo rotatory nystagymus towards the affected side
152
How is the cochlear portion of CN VIII tested?
Rinne and Weber tests
Rinne -place tuning fork on mastoid till the sound stops and then hold in the air by the EAM
Air conduction should be better than bone conduction
Conduction deafness: NO note at EAM
Weber - place tuning fork on forehead and ask whether patient hears it louder on one side (lateralisation)
Normally there is no lateralisation
Conduction deafness: sound loudest in affected ear
Sensorineural deafness: sound loudest in normal ear
153
Which 4 things exit through the jugular foramen?
1. CN IX
2. CN X
3. CN XI
4. Internal jugular vein
154
How are CN IX and X tested?
Gag reflex
CN IX = sensory portion
CN X = motor portion
155
How is CN XI tested?
Ask patient to shrug shoulders (with added pressure)
Ask to rotate neck (axial) and feel sternocleidomastoid contraction
SCM weakness can sometimes lead to head turned to weak side at rest
Testing the spinal part (C1-C5)
156
Why might CN XI be damaged?
Neck surgery
Trauma
Traction injury (stretch in region)
157
Which muscle of the tongue does CN XII not innervate?
Palatoglossus (CN X)
158
How would a CN XII lesion present?
If ask to stick tongue out, it will deviate towards the weakened side
May also have muscle wasting and fasiculations
159
What is next to the 3rd ventricle on either side?
Thalamus (thalami)
160
What does the caudate nucleus run next to?
Lateral ventricle
161
Where does the substantia nigra sit?
Midbrain
162
What is the lentiform nucleus made up of?
Putamen
Globus pallidus internal
Globus pallidus external
163
What is the pallidum made up of?
Globus pallidus internal
Globus pallidus external
Substantia nigra pars reticula
164
What is the striatum made up of?
Caudate nucleus and putamen
165
What is an immediate lateral relation of the thalamus?
Internal capsule
166
Which receptors does dopamine act on in the direct pathway?
D1 receptors
167
Which receptors does dopamine act on in the indirect pathway?
D2 receptors
168
In the direct pathway, what does the striaum act on?
Globus pallidus internal and substantia nigra pars reticula
169
In the direct pathway, what do globus pallidus internal and substantia nigra pars reticula act on?
Thalamus (ventral anterior and lateral nuclei)
170
In BG pathways, what does the thalamus act on?
Motor cortex
171
In the indirect pathway, what does the striatum act on?
Globus pallidus external
172
In the indirect pathway, what does globus pallidus external act on?
Subthalamic nucleus
173
In the indirect pathway, what does the subthalamic nucleus act on?
Globus pallidus internal and substantia nigra pars reticula
174
In the indirect pathway, what do globus pallidus internal and substantia nigra pars reticula act on?
Thalamus (ventral anterior and lateral nuclei)
175
Explain how dopamine acts on the indirect pathway
Substantia nigra pars compacta inhibits the striatum via dopamine action on D2 receptors
176
What are the 5 levels of the glasgow outcome score used for patients with head injury?
1. Dead
2. Vegetative state
3. Severely disabled
4. Moderately disabled
5. Good recovery
177
What is the classic shape of an extradural haemotoma?
Convex lens shape which forms because the blood pushes against the tough dura but cannot rupture it
178
What is the classic shape of a subdural haemorrhage?
Crescent shape as they follow the shape of the brain, but do not penetrate into the arachnoid space or sulci
179
What is normal intracranial pressure?
~10mmHg (between 5-15mmHg)
180
How is cerebral perfusion pressure calculated?
CPP = MAP - ICP
CPP above 60mmHg is fine
e.g. 90-10 = 80 mmHg
181
How does CO2 affect cerebral blood flow?
CO2 dilates the arteries due to acidosis (H+)
| Therefore, if have increased CO2, there is risk of increased ICP
182
What is normal blood pCO2?
4-6kPa
183
What is normal CBF?
50ml/100g/min
