Neuroanatomy Flashcards
1
Q
Where are multipolar neurones typically present?
A
Skeletal muscle
ANS
2
Q
Where are the soma of multipolar neurones typically found?
A
In CNS (presynaptic neurone for ANS)
3
Q
Where are the soma of unipolar/pseudounipolar neurones found?
A
PNS - Dorsal root ganglion
4
Q
What is the name for a collection nerve cell bodies in the CNS?
A
Nucleus
5
Q
What is the name for a collection nerve cell bodies in the PNS?
A
Ganglion
6
Q
What is the name for a bundle of axons in the CNS?
A
Tract
7
Q
What is the name for a bundle of axons in the PNS?
A
Nerve
8
Q
Where are spinal nerves located?
A
Only within the intervertebral foraminae
9
Q
How do spinal nerves connect to the soma?
A
Via rami
10
Q
How do spinal nerves connect to the spinal cord segment of the same number>
A
Via roots and rootlets
11
Q
Which are bigger, posterior rami or anterior rami?
A
Anterior
12
Q
What is the course of a sensory axon?
A
Passes from the spinal nerve…
…into the posterior root…
…into the posterior rootlets…
…into the dorsal horn of the spinal cord
13
Q
What is the course of a motor axon?
A
Passes from ventral horn of the spinal cord…
…into the anterior rootlets…
…into the anterior root…
…into the spinal nerve
14
Q
Where does the spinothalamic tract decussate?
A
In spinal cord (Usually 1-2 spinal levels above point of entry)
15
Q
What dermatomal map is used in Dundee?
A
Foerster map
16
Q
What does each segment of the body wall receive in terms of nervous supply?
A
General sensory supply (to all structures) Motor supply (to skeletal muscles) Sympathetic supply to: - Skin - Smooth muscles of all arterioles
17
Q
What spinal level is the male nipple?
A
T4
18
Q
What spinal level is the umbilicus?
A
T10
19
Q
What spinal levels supply the posterior scalp, neck and shoulder?
A
C2-C4
20
Q
What spinal levels supply the upper limb?
A
C5-T1
21
Q
What spinal levels supply the lower limb, gluteal region and perineum?
A
L2-Coccygeal segment
22
Q
What spinal levels make up the cervical plexus?
A
C1-C4
23
Q
What does the cervical plexus supply?
A
Posterior scalp
Neck wall
Diaphragm
24
Q
What spinal levels make up the brachial plexus?
A
C5-T1
25
What does the brachial plexus supply?
Upper limb
26
What spinal levels make up the lumbar plexus?
L1-L4
27
What does the lumbar plexus supply?
Lower limb
28
What spinal levels make up the sacral plexus?
L5-S4
29
What does the sacral plexus supply?
Lower limb
Gluteal region
Perineum
30
What segments of the spinal cord have lateral horns?
T1-L2
31
Why do some spinal cord segments have lateral horns?
For soma of the next SNS neurone in the chain
32
Presynaptic axons providing sympathetic outflow to the heart synapse where?
T1 or Cervical paravertebral ganglia
33
Postsynaptic axons providing sympathetic outflow to the heart travel in what nerves?
Cardiopulmonary splanchnic nerves
34
Where do postsynaptic sympathetic axons travel to in the heart?
SA node
AV node
Myocardium
35
Presynaptic axons providing sympathetic outflow to the lungs synapse where?
Upper thoracic paravertebral ganglia
36
Postsynaptic axons providing sympathetic outflow to the lungs travel in what nerves?
Cardiopulmonary splanchnic nerves
37
Where do postsynaptic sympathetic axons travel to in the lungs?
Bronchiolar smooth muscle
| Mucous glands
38
Presynaptic axons providing sympathetic outflow to the foregut synapse where?
Celiac ganglion of the celiac plexus
39
Presynaptic axons providing sympathetic outflow to the kidney synapse where?
Aorticorenal ganglion
40
Presynaptic axons providing sympathetic outflow to the midgut synapse where?
Superior mesenteric ganglion of the superior mesenteric plexus
41
Presynaptic axons providing sympathetic outflow to the hindgut and pelvic/perineal organs synapse where?
Inferior mesenteric ganglion of the inferior mesenteric plexus
42
Presynaptic axons providing sympathetic outflow to the adrenal medulle synapse where?
Directly onto adrenaline/NA secreting cells of the adrenal medulla (pas through aorticorenal ganglion without synapsing
43
Why is there ipsilateral ptosis in Horner's syndrome?
Lack of SNS innervation to levator palpebrae superioris smooth muscle
44
Why is there ipsilateral miosis in Horner's syndrome?
No SNS innervation to dilator pupillae
45
What causes Horner's syndrome?
Cervical sympathetic chain compression
46
What lung tumour causes Horner's syndrome?
Pancoast tumour (most are non-small cell)
47
How do parasympathetic fibres reach the eye?
Via the ciliary ganglion
48
Parasympathetic fibres which travel through parasympathetic ganglia in the head travel to what structures?
Lacrimal glands
| Salivary glands
49
Parasympathetic fibres in the vagus nerve supply what structures?
Neck
Chest
Abdomen (as far as midgut)
50
Parasympathetic fibres in the sacral spinal nerves supply what structures?
Hindgut
Pelvis
Perineum
51
Where do the extrinsic back muscle attach?
Back
| To the upper limb/pectoral girdle
52
What is the function of the extrinsic back muscles?
Move the upper limb
53
What are the main extrinsic back muscles? What is their nerve supply?
Trapezius (CN XI)
Latissimus dorsi (Thoracodorsal nerve/C5-C7)
Levator scapulae (Cervical nerve/C3-C4 and Dorsal scapular nerve/C5)
Rhomboids (Dorsal scapular nerve)
54
The erector spinae and transversospinalis muscles are what type of back muscles?
Intrinsic
55
What is the function of the erector spinae and transversospinalis muscles?
Maintain back posture
| Move the vertebral column
56
What are the three muscle groups of the erector spinae? (From medial to lateral) What are there insertions?
Spinalis (spinous processes)
Longissimus (transverse processes)
Iliocostalis (ribs)
57
What is the inferior attachment of the erector spinae muscles?
Common tendon to the:
- Sacrum AND
- Iliac crest
58
Where is the transversospinalis located?
Within the deep grooves between the transverse and spinous processes
59
What do the transversospinalis muscles lie superficial to?
Laminae
| Articular processes
60
What muscles are responsible for back extension?
Intrinsic back muscles
61
What muscles are responsible for back flexion?
```
Psoas major (main)
Rectus abdominis
```
62
Via what do pain signals from the facet joints and intervertebral discs travel?
Posterior rami
63
What ligament connects adjacent laminae posterior to spinal cord?
Ligamentum flavum
64
Where does the posterior longitudinal ligament attach to?
Posterior aspect of all:
- Vertebral bodies
- Intervertebral discs
65
What does the posterior longitudinal ligament prevent?
Over-flexion of spine
66
Where does the anterior longitudinal ligament attach to?
Anterior aspects of all:
- Vertebral bodies
- Intervertebral discs
67
Why is an intervertebral disc more likely to prolapse posteriorly than anteriorly?
Posterior longitudinal ligament is weaker and provides less support to the discs than the anterior longitudinal ligament
68
What does the anterior longitudinal ligament prevent?
Over-extension of the spine
69
What connects the tips of spinous processes?
Supraspinous ligament
70
What does the interspinous ligament connect?
Superior and inferior surfaces of spinous processes
71
Each cervical vertebra has a transverse foramina; why?
Passage of vertebral arteries
72
What is the special name given to:
- C1
- C2
- C7
```
C1 = Atlas
C2 = Axis
C7 = Vertebrae prominens
```
73
What are the atlanto-ocipital joints between?
Occipital condyles AND
| Superior articular facets of the atlas/C1
74
How many joints exist between the atlas and the axis?
3:
- 2 facet joints
- 1 between anterior arch of atlas and odontoid process
75
What is the sacral promontory? What does it articulate with?
Part of the border of the pelvic inlet (posteriorly)
| Articulates with L5 (Sacrovertebral angle)
76
Instead of intervertebral foraminae, how does the sacrum permit the passage of anterior and posterior rami of the sacral spinal nerves?
Anterior sacral foraminae
| Posterior sacral foraminae
77
What does the sacral canal contain?
Cauda equina
| Meninges
78
What does the sacral canal end in?
Sacral hiatus
79
In the spinal canal, what is the dural sac surrounded by?
Epidural fat (in epidural space)
80
Where are extradural venous sinuses located?
In the epidural fat
81
Where does the spinal cord begin and end?
C1
| L2
82
What is the name of the ending of the spinal cord?
Conus medullaris
83
Why might a laminectomy be carried out?
Relieve pressure on cord/roots due to:
- Tumour
- Herniated disc
- Bone hypertrophy
84
How does a spinal nerve connect to a sympathetic ganglion?
Via grey and white rami communicantes
85
What are somatic general sensory symptoms?
```
Pain (neuralgia)
Paraesthesia
Anaesthesia
Hyperaesthesia
Hot/Cold
Ataxia (loss of balance/coordination)
```
86
What are somatic motor symptoms?
Muscle stiffness/tightness/spasm
Hypotonia (LMN) or Hypertonia (UMN)
Reduced power
Ataxia
87
Where is a common locations of CVAs that may result in sensory pathology?
Internal capsule
88
C2 dermatome
Back of scalp and Adam's apple
89
C3 dermatome
Back of neck and jugular notch
90
C4 dermatome
Clavicle and shoulder tip
91
C5 dermatome
Regimental badge area
92
C6 dermatome
Thumb
93
C7 dermatome
Middle finger
94
C8 dermatome
Little finger
95
T1 dermatome
Medial forearm
96
T2 dermatome
Medial arm and sternal angle
97
T4 dermatome
Male nipple
98
T8 dermatome
Ziphoid process
99
T10 dermatome
Umbilicus
100
T12 dermatome
Pubic symphysis
101
L1 dermatome
Groin ('hands in pockets')
102
L2 dermatome
Anterior thigh
103
L3 dermatome
Anterior knee
104
L4 dermatome
Medial malleolus
105
L5 dermatome
Dorsum of foot
106
S1 dermatome
Heel
107
S2 dermatome
Posterior knee
108
S3 dermatome
Buttocks
109
S4 dermatome
Perineum
110
S5 dermatome
Perianal skin
111
What is the cutaneous innervation of the lesser occipital (C2) nerve?
Skin posterior to external ear
112
What is the cutaneous innervation of the greater auricular (C2, C3) nerve?
Skin over angle of mandible and some of external ear
113
What its the cutaneous innervation of the transverse cervical (C2, C3) nerve?
Skin on anterior neck
114
What is the cutaneous innervation of the supraclavicular (C3, C4) nerve?
Skin over clavicle and shoulder tip
115
Where is the 'nerve point' of the neck? Why is this clinically important?
Midpoint of the posterior border of the SCM
| Take cure during biopsy - cervical plexus
116
The anterior rami of T2-T11 spinal nerves are called what?
Intercostal nerves
117
The spinal nerves of T7-T11 continue as what?
Thoracoabdominal nerves
118
The T12 anterior ramus forms what nerve?
Subcostal nerve
119
What does the bifurcation of the anterior rami of L1 spinal nerves form?
Iliohypogastric nerves
| Ilioinguinal nerves
120
How can we assess the cervical plexus?
Neck postural and strap muscles
| Diaphragm
121
How can we assess the brachial plexus?
Upper limb muscles
| Extrinsic back muscles
122
What supplies the motor control to the strap muscles?
Cervical plexus (C1-C3)
123
What supplies the diaphragm?
Phrenic nerve (C3, C4 and C5)
124
What supplies the SCM and trapezius?
CN XI
125
What supplies the pharyngeal muscles and the intrinsic laryngeal muscles?
CN X
126
What nerve supplies the deltoid and the teres minor?
Axillary nerve (C5, C6)
127
What nerve supplies the anterior arm compartment (biceps, brachialis, coracobrachialis)?
Musculocutaneous nerve (C5-C7)
128
What does the radial nerve supply?
```
Triceps (posterior arm)
Posterior forearm:
- Brachioradialis
- Supinator
- All extensors of carpus and digits
- Abductor pollicis longus
```
129
What nerve roots form the radial nerve
C5-T1 (entire brachial plexus)
130
What does the median nerve supply?
```
Anterior forearm:
- Pronators
- Flexor carpi radialis
- Palmaris longus
- Flexor digitorum superficialis
- Lateral half of flexor digitorum profundus
- Flexor pollicis longus
Muscles of the hand:
- Thenar
- Lumbricals 1 and 2
```
131
What does the ulnar nerve supply?
```
Anterior forearm:
- Flexor carpi ulnaris
- Medial half of flexor digitorum profundus
- Adductor pollicis
Muscles of the hand:
- Hypothenars
- Lumbricals 3 and 4
- All the interossei (dorsal and palmar)
```
132
What does the femoral nerve supply?
Anterior thigh:
- Quadriceps
- Sartorius
Pectineus
133
What does the obturator nerve supply?
All of medial thigh:
- All adducttors (brevis, longus and magnus)
- Gracilis
134
What does the tibial nerve supply?
```
Posterior thigh (True hamstrings):
- Semimembranous
- Semitendinosus
- Long head of biceps femoris
Posterior leg:
- Gastrocnemius
- Soleus
- Plantaris
- Popliteus
- Tibialis posterior
- Flexors of digits (Digitorum and hallucis longus)
All intrinsic sole muscles
```
135
What does the common fibular nerve supply?
Short head of biceps femoris
136
What does the superficial fibular nerve supply?
Lateral leg:
- Fibularis longus
- Fibularis brevis
137
What does the deep fibular nerve supply?
```
Anterior leg:
- Tibialis anterior
- Extensor digitorum and hallucis longus
- Fibularis tertius
Dorsum of the foot:
- Extensor digitorum brevis
- Extensor hallucis brevis
```
138
Where does the extracranial part of the olfactory nerve lie?
Olfactory mucosa
139
What is the cranial foramina for CN i?
Cribiform plate (anterior fossa)
140
Where do the olfactory nerves synapse?
Olfactory bulb
141
How do the olfactory nerves get to the cortex?
Via olfactory tracts
142
What is the cranial foramina for CN ii?
Optic canal (middle fossa)
143
What is the intracranial path of CN ii?
Travels around pituitary stalk to optic chiasm
| Forms optic tract
144
Where does CN ii connect to the CNS?
Diencephalon
145
What are the functions of CN iii?
Motor - Eye movement
| PNS - Pupil constriction
146
Where does CN iii connect to the CNS?
Midbrain (mesencephalon)
147
Where do CNs iii, iv and vi leave the skull?
Superior orbital fissure (middle fossa)
148
What is the intracranial course of CNs iii, iv and vi?
Travels towards orbit in lateral wall of cavernous sinus
149
What muscles does CN iii supply?
```
Medial rectus
Superior rectus
Inferior rectus
Inferior oblique
Levator palpebrae superioris
```
150
What muscle does CN iv supply?
Superior oblique
151
What muscle does CN vi supply?
Lateral rectus
152
What is the extracranial part of CN viii?
Axons from cochlear and vestibular apparatus
153
What is the cranial foramina for CN viii?
Internal acoustic meatus (posterior fossa)
154
What is the intracranial path of CN viii?
Travels posteromedially from IAM to the pontomedullary junction
155
Where does CN xi connect to the CNS?
Cervical spinal cord
156
What is the intracranial path of CN xi?
Ascends through foramen magnum
| Travels towards jugular foramen
157
Where does CN xi leave the cranium?
Jugular foramen (posterior fossa)
158
Where does CN xii join the CNS?
Via rootlets lateral to the pyramids of the medulla
159
What is the intracranial path of CN xii?
Travels anteriorly to hypoglossal canal (posterior fossa)
160
What is the extracranial pathy of CN xii?
Descends lateral to carotid sheath
At level of the hyoid:
- Turns anteriorly
- Moves towards lateral aspect of tongue
161
What is the one tongue muscle CN xii doesn't supply?
Palatoglossus
162
What is the CNS connection of CN v?
Pons:
- Laterally
- Midway between medulla and midbrain
163
What is the intracranial path of CN v?
Inferior to edge of tentorium cerebelli (between posterior and middle fossae)
164
Where does CN v leave the cranium?
v1 - Superior orbital fissure
v2 - Foramen rotundum
V3 - Foramen ovale
165
What cranial nerve forms the afferent part of the corneal reflex?
```
Ophthalmic nerve (CN v1)
(Long ciliary nerve)
```
166
What sinus does the ophthalmic nerve not supply?
Maxillary
167
What cranial nerve supplies the anterior and posterior cranial fossae?
Ophthalmic nerve (CN c1)
168
What cranial nerve supplies the middle cranial fossa?
Mandibular nerve (CN v3)
169
Which of the muscles supplied by CN v3 is the jaw opening muscles?
Lateral ptyergoid
170
Apart from the jaw opening/closing muscles, what other two muscles does CN v3 supply?
Tensor veli palatini
| Tensor tympani
171
Where does CN vii connect to the CNS?
Antertolaterally at pontomedullary junction
172
What is the cranial foramina for CN vii?
Temporal bone:
- IMA (in)
- Facial canal
- Stylomastoid foramen (out)
173
What does CN vii give motor supply to?
Most fibres pass through parotid gland (but do not supply it)
Muscles of facial expression
174
In the stylomastoid foramen, what nerve modality is CN vii carying?
ONLY somatic motor (to muscles of facial expression)
175
What branches off before the stylomastoid foramen (CN vii)? What is its function?
Chorda tympani:
- Special sensory to anterior 2/3 of tongue
- PNS to sublingual and submandibular
176
What is the general sensory supply of CN ix?
```
Posterior third of tongue
Mucosa of naso- and oropharynx
Mucosa of some of laryngopharynx
Palatine tonsils
Eustachian tube
Middle ear cavity
```
177
What is the special sensory supply of CN ix?
Vallate papillae on posterior third of tongue
178
What are the visceral afferent (sensory) supply of CN ix?
Carotid sinus:
- Baroreceptors
- Chemoreceptors
179
What muscle does CN ix give motor supply to?
Stylopharyngeus
180
What do the PNS fibres in CN ix supply?
Parotid gland
181
What is the CNS connection of CN x?
Lateral aspect of medulla (immediately inferior to CN ix)
182
What is the path of CN x in the neck?
Runs in carotid sheath posterior to and between:
- Common carotid
- Internal jugular
183
What branch of CN x supplies the laryngeal muscles?
Recurrent laryngeal
184
What is the route of the CN x branch supplying the laryngeal muscles?
Left - Curves under aorta
| Right - Curves under right subclavian artery
185
In the thorax, where does the right CN x run along?
Lateral aspect of trachea
186
In the thorax, where does the left CN x run along?
Lateral aspect of aortic arch
187
In the thorax, both CN x pass posterior to what to run alongside what?
Pass posterior to lung root
| Onto oesophagus
188
What structure does CN x pierce and at what spinal level?
Diaphragm
| T10
189
In the abdomen, what structure does CN x pass onto?
Stomach
190
In the abdomen, where do the last branches of CN x pass to?
Splenic flexure of colon
191
What are the five layers of the scalp?
```
S - Skin
C - Connective tissue (contains named scalp arteries)
A - Aponeurosis
L - Loose connective tissue
P - Pericranium
```
192
What bones form the pterion?
Frontal
Parietal
Temporal
Sphenoid
193
What courses over the deep aspect of the pterion?
Middle meningeal artery
194
What causes the pain in meningitis?
Stretching of the dura
195
What provides sensory supply to the dura?
CN v
196
What does the dura enclose?
Dural venous sinuses
197
What are arachnoid granulations?
Extensions of arachnoid into the dural venous sinuses
198
What is the function of arachnoid granulations?
Reabsorb CSF from subarachnoid space into the venous system
199
What is the diaphragm sellae?
Tough sheet of dura over pituitary fossa
200
What is the tentorium cerebelli?
Tough sheet of dura over the cerebellum
201
Where does the tentorium cerebelli attach?
Ridges of petrous temporal bones
202
Why does the tentorium cerebelli have a central gap?
To allow passage of the brainstem
203
What is the falx cerebri?
Midline structure made of dura
204
Where does the falx cerebri attach?
Deep aspect of skull:
- Crista galli of ethmoid (anteriorly)
- Internal aspect of sagittal suture
- Internal occipital protuberance (posteriorly)
205
What is the function of the falx cerebri?
Separates the right and left hemispheres
206
Where does the superior sagittal sinus lie?
Superior border of falx cerebri
207
Where does the inferior sagittal sinus lie?
Inferior border of falx cerebri
208
What do the inferior sagittal sinus and great cerebral vein form?
Straight sinus
209
Where does the confluence of the sinuses lie?
In the midline at the internal occipital protuberance
210
What veins make up the confluence of the sinuses?
Superior sagittal sinus
Straight sinus
(Occipital sinus)
211
Where does the confluence of the sinuses drain to?
Transverse sinus
212
Where do cerebral veins drain to?
Superior and inferior sagittal sinuses
213
What is the sigmoid sinus?
Continuation of the transverse sinus
214
Where does the sigmoid sinus drain and at what foramen?
Internal jugular veins at the jugular foramen
215
What is the danger triangle?
Facial vein is very superficial and drains to internal jugular
Risk of spread of infection
216
Via what does the internal carotid enter the cranium?
Carotid canal
217
From what artery do the vertebral arteries branch off?
Subclavian arteries
218
How do the vertebral arteries enter the skull?
Via foramen magnum
219
What structures do the vertebral arteries supply?
Meninges
| Cerebellum
220
What do the anterior cerebral arteries supply?
Medial aspects of the cerebral hemispheres
221
In anterior cerebral artery syndrome (eg due to stroke) what symptoms are seen?
Hemiparesis and sensory loss of contralateral lower limbs
Apraxia
Anosmia
Urinary incontinence
222
What do the middle cerebral arteries supply?
Lateral aspects of the cerebral hemispheres
223
In middle cerebral artery syndrome (eg due to stroke) what symptoms are seen?
Hemiparesis and sensory loss of:
- Contralateral lower half of face
- Contralateral upper limbs (and lower limbs)
Ataxia of contralateral side (greatest in face and upper limbs)
Aphasia
Anosognosia
224
What do the posterior cerebral arteries supply?
Posterior aspects of cerebral hemisphers
| Visual cortex
225
In posterior cerebral artery syndrome (eg due to stroke) what symptoms are seen?
Contralateral loss of pain and temperature sense
Contralateral hemianopia with macular sparing
Ipsilateral deficits of CN iii
Horner's syndrome
226
Where is the Circle of Willis located?
```
Inferior to the midbrain
Close to:
- Pituitary stalk
- Optic chiasm
Within subarachnoid space
```
227
What vessels make up the Circle of Willis?
```
Anterior cerebral arteries
Posterior cerebral arteries
Anterior communicating arteries
Posterior communicating arteries
Internal carotid arteries
(Basilar artery)
```
228
What volume of CSF circulates in the subarachnoid space daily?
400-500ml
229
What produces CSF?
Choroid plexuses of the ventricles
230
Where can CSF be obtained and how?
L3/L4 or L4/L5
| Via LP
231
Where does the subarachnoid space close?
S2
232
Where are the lateral ventricles located?
In their respective hemispheres
233
Where is the third ventricle located?
In the midline in the diencephalon
234
Where is the fourth ventricle located?
Between the cerebellum and the pons
235
Describe the circulation of CSF
1. Secreted by choroid plexus into lateral and third ventricles
2. Travels via the left and right Foraminae of Munro...
3. Into the third ventricle
4. It then flows into the cerebral aqueduct (in midbrain)
5. Then flows into the fourth ventricle
6. Then flows into SA space (mainly) OR the central canal of the spinal cord
236
How is hydrocephalus treated?
Ventricular peritoneal shunt
237
What kind of intracranial haemorrhage can occur due to middle meningeal artery injury?
Epidural/Extradural
238
What typically causes a subdural haemorrhage?
Torn cerebral veins - Falls in the elderly
239
What typically causes a subarachnoid haemorrhage?
Ruptured berry aneurysm
| Ruptured congenital aneurysm
240
What layers are passed through for epidural anaesthesia?
```
Skin
Subcutaneous fat
Supraspinous ligament
Intraspinous ligament
Ligamentum flavum
Epidural space (fat and veins)
```
241
In a lumbar puncture, what layers are passed through?
```
Skin
Subcutaneous fat
Supraspinous ligament
Intraspinous ligament
Ligamentum flavum
Epidural space (fat and veins)
Dura and subarachnoid (simultaneously)
```
242
What can damage to the epidural venous sinuses cause?
Epidural haemorrhage
243
When would we not carry out an LP? Why?
In situations were ICP is raised (idiopathic)
| May cause uncal (transtentorial herniation
244
When might an LP be carried out in raised ICP?
To lower ICP (therapeutic) when an obstruction (eg. of the third ventricle) has been ruled out
245
How many visible swellings are visible initially in the development of the nervous system?
3 vesicles (neural tube)
246
What happens that results in 5 vesicles?
1st and 3rd vesicles subdivide
247
What secondary vesicle forms the cerebral hemispheres?
Telencephalon
248
What secondary vesicle forms the thalamus and hypothalamus?
Diencephalon
249
What secondary vesicle forms the midbrain?
Mesencephalon
250
What secondary vesicle forms the pons and cerebellum?
Metencephalon
251
What secondary vesicle forms the medulla?
Myeloncephalon
252
What is the function of astrocytes?
Support
| Maintain BBB and homeostasis
253
What shape are astrocytes?
Star
254
What is the function of oligodendrocytes?
Produce myelin in CNS
255
What shape is the nucleus in oligodendrocytes?
Round
256
What is the function of microglia?
Immune monitoring and Ag presentation
| Haemopoietic origin - similar to macrophages
257
At rest, what shape are mircroglia?
Long nucleus
| Short, spiny cell processes
258
When activated, what shape are microglia?
Round
259
What is the function of ependymal cells?
```
Line ventricles (ciliated cuboidal/columnar epithelium)
Produce CSF
```
260
What is a folium?
The equivalent of a gyrus but in the cerebellum
261
Where is the grey matter in relation to the white matter in the brain?
External
262
Where is the grey matter in relation to the white matter in the spinal cord?
Internal
263
Why is white matter white?
Myelin
264
Which lobe is anterior to the central sulcus and superior to the lateral sulcus?
Frontal lobe
265
Which lobe is posterior to the central sulcus, superior to the lateral sulcus and anterior to a line from the parieto-occipital sulcus to the preoccipital notch?
Parietal lobe
266
Which lobe is posterior to a line from the parieto-occipital sulcus to the preoccipital notch?
Occipital lobe
267
Which lobe is inferior to the lateral sulcus and bordered posteriorly by a line from the parieto-occipital sulcus to the preoccipital notch?
Temporal lobe
268
What does the insular lobe play a role in?
Experience of pain
269
Where is the myenteric plexus found?
Between the outer layers of smooth muscle in the gut
270
Where is the submucosal plexus found?
In submucosa of the walls of the gut
271
How are the posterior roots enlarged when they pass through the intervertebral foraminae?
By dorsal root ganglia
272
How does the conus medullaris continue? What is it anchored to?
Filum terminate
| Anchored to dorsum of coccyx
273
What is the function of the denticulate ligament?
Suspends spinal cord in the spinal canal
274
Where is the denticulate ligament located?
On the lateral aspects of the spinal cord
275
What makes up the denticulate ligament?
Pial and arachnoid tissues
276
What is white matter composed of in the spinal cord?
Longitudinally orientated axons
Glial cells
Blood vessels
277
What is contained in the grey matter in the spinal cord?
```
Soma
Cell processes
Synapses
Glia
Blood vessels
```
278
How is the grey matter in the spinal cord divided?
Left
Right
Posterior
Anterior
279
What is the horizontal part of the 'H' of the grey matter in the spinal cord called?
Dorsal and ventral grey commisures
280
What are the three main longitudinal arteries of the spinal cord?
Anterior spinal artery
| 2 posterior spinal arteries
281
Where do the three longitudinal arteries arise?
From the vertebral arteries
282
Where are the segmental arteries derived from?
Vertebral, intercostal and lumbar arteries
283
What arteries travel along dorsal and ventral roots?
Radicular arteries
284
What veins drain the spinal cord?
Longitudinal and segmental veins
285
What can a CVA of the internal capsule cause?
Lack of control of the corticospinal tract:
- Spastic paralysis
- Hyperflexion of the upper limbs
- Decorticate posturing
286
What tract is thought to play a role in decerebate posturing?
Vestibulospinal tract
287
What are the motor consequences of Brown-Sequard's Syndrome?
Ipsilateral paralysis
Ipsilateral hyperreflexia
Extensor plantar reflex
288
What are the sensory consequences of Brown-Sequard's Syndrome?
Ipsilateral loss of proprioception and vibratory sense
| Contralateral loss of pain and temp. sensation
289
What separates the anterior and posterior lobes of the cerebellum?
Primary fissure
290
What runs through the posterior lobe of the cerebellum?
Horizontal fissure
291
The posterior fissure separates the posterior lobe of the cerebellum from what lobe?
Flocculonodular lobe:
- Nodule
- Flocculus
292
How is the cerebellum attached to the brainstem?
Via 3 peduncles
293
What are the cerebellar vermises?
Medial, corticonuclear zones of the cerebellum
294
What parts of the cerebellum form the spinocerebellum?
Mainly the vermis (ie medial part)
295
What parts of the cerebellum form the vestibulocerebellum?
Flocculonodular lobe
296
What parts of the cerebellum form the cerebrocerebellum/pontocerebellum?
Lateral parts of the hemispheres
297
Deep grey matter has white matter 'foliage' known as?
Folia
298
What is the deep grey matter of the cerebellum called?
Deep cerebellar nuclei
299
The cortex is divided into 3 layers. What are they?
```
Molecular layer (outer)
Purkinje cell layer (middle)
Granular layer (inner)
```
300
What afferent projections come to the cerebellum?
```
Spinal cord:
- Somatic proprioception
- Pressure
Cerebral cortex (via pons)
Vestibular apparatus (via vestibular nuclei)
```
301
What layer do most inputs into the cerebellum go?
Granular layer
302
What layer do all outputs of the cerebellum leave through?
Purkinje cell layer
303
What do cerebellar outputs contribute to?
Coordinating ALL motor tracts:
- Corticospinal
- Rubrospinal
- Vestibulospinal
304
When cerebellar efferents leave, where do they decussate and synapse?
Most in the thalamus
305
What are the signs/symptoms of a midline cerebellar lesion?
Disturbance in posture control
| Falling when standing/sitting despite preserved limb control
306
What are the signs/symptoms of a unilateral hemispheric cerebellar lesion?
Disturbance of limb coordination
Intention tremor:
- Broad and low frequency (~5Hz)
Unsteady gait
307
What are the signs/symptoms of bilateral cerebellar dysfunction?
Dysarthria (slow, slurred speech)
Cerebellar ataxia:
- Bilateral incoordination of the arms
- Wide based gait
308
What substance can cause bilateral cerebellar dysfunction?
Alcohol
309
What are the functions of the basal ganglia?
```
Facilitates purposeful movement
Inhibits unwanted movements
Role in:
- Posture
- Muscle tone
```
310
What parts of the basal ganglia form the striatum?
Caudate nucleus
Putamen
(NB Both are homonymous in function)
311
What parts of the basal ganglia form the lenticular/lentiform nucleus?
Putamen
| Globus Pallidus
312
What parts of the basal ganglia form the corpus striatum?
Caudate nucleus
Putamen
Globus Pallidus
313
What five structures make up the basal ganglia?
```
Caudate nucleus
Putamen
Globus Pallidus
Subthalamic nucleus
Substantia nigra
```
314
What separates the lentiform nucleus and the caudate nucleus?
Internal capsule
315
What causes Parkinson's Disease?
Degeneration of the dopaminergic neurones of the substantia nigra
316
How does the basal ganglia enhance movement?
Direct pathway enhances thalamic outflow
317
How does the basal ganglia inhibit movement?
Indirect pathway inhibits thalamic outflow
318
Do unilateral lesions of the basal ganglia affect the ipsi- or contralateral side of the body?
Contralateral
319
What signs/symptoms are present in basal ganglia lesions?
Motor signs:
- Changes in muscle tone
- Dyskinesias (Tremor, chorea [distal limbs], myoclonus)
320
What causes Huntington's Disease?
Progressive degeneration of basal ganglia and cerebral cortex
321
What can the signs and symptoms of basal ganglia lesions be referred to as?
Extrapyramidal
322
Where are the nuclei of CN iii located?
Midline of superior colliculus (Edinger-Westphal Nucleus and Oculomotor nucleus)
323
Where is the nucleus of CN iv?
Midline of inferior colliculus (lower midbrain)
324
Where is the nucleus of CN vi?
Midline and very caudal in pons
325
Where is the nucleus of CN xii?
In the midline
326
Where is the sensory nucleus of CN v?
Stretches from midbrain down to upper 2 segments of cervical spinal cord
327
What info does the mesencephalic nucleus receive from CN v?
Proprioceptive from chewing muscles
328
Where is the mesencephalic nucleus?
Extends from upper pons to midbrain
329
One pathway from the mesencephalic nucleus connect to the trigeminal motor nucleus. What function does this serve?
Jaw reflex
330
What function does the pontine trigeminal/principal nucleus serve?
Processes discriminative touch and vibration
331
What tracts does the pontine trigeminal nucleus project into?
Dorsal trigeminothalamic tracts (Bilateral to VPM)
332
What function does the spinal nucleus serve?
Processes pain and temperature sensations
333
What sensations enter more superiorly in the spinal nucleus?
Perioral
334
What are the 3 components of CN vii?
```
Facial motor nucleus
Superior salivary nucleus (PNS)
Solitary nucleus (taste)
```
335
What is the path of the motor CN vii axons?
Loop around CN vi
336
What are the 4 components of CN ix?
```
Solitary nucleus (taste)
Commissural nucleus (visceral)
Inferior salivary nucleus (PNS)
Nucleus ambiguus (motor from stylopharyngeus)
```
337
What are the 4 components of CN x?
```
Solitary nucleus (taste)
Commissural nucleus (visceral)
Dorsal motor nucleus (PNS)
Nucleus ambiguus (motor)
```
338
What is the corticobulbar tract?
Part of the pyramidal tract:
| - Motor supply to cranial nerves
339
Where are PNS efferent inputs mainly from in regards to cranial nerves?
Hypothalamus
340
What organs does the cochlea contain?
Organs of Corti (composed of hair cells)
341
What do the cochlear nuclei span?
Pontomedullary junction
342
What nuclei are important in sound localisation?
Superior olivary nucleus (pons)
| Nucleus of lateral lemniscus
343
What lobe is the primary auditory cortex located in?
Temporal lobe
344
What is the function of Wernicke's area?
Comprehension of spoken and written language
345
Where is Wernicke's area located?
Superior temporal gyrus
346
What part of the auditory cortex do low frequency sounds travel to?
Anterolateral
347
What part of the auditory cortex do high frequency sounds travel to?
Posteromedial
348
What is Broca's area responsible for?
Production of spoken and written language
349
Where is Broca's area located?
Inferior frontal gyrus
350
What does damage to Broca's area result in?
Expressive aphasia:
- Using only a few words
- Only saying the important words in a sentence
351
What does damage to Wernicke's area result in?
Receptive aphasia:
- Words placed out of order
- Meaningless words spoken
352
To what structures does the vestibular nucleus connect?
Thalamus
CNs iii, iv and iv nuclei
Cerebellum
Spinal cord
353
What areas receive vestibular input?
```
Posterior insula
Parietal lobe just posterior to postcentral gyrud
Midway between:
- Apex of brain AND
- Lateral fissure
```
354
When the optic tract projects to the Lateral Geniculate Nucleus, where does it go?
To optic radiations and then to visual cortex
355
What part of the occipital cortex receives the most inputs from the Lateral Geniculate Nucleus?
Layer 4
356
How many layers are there in the occipital cortex?
6
357
When the optic tract projects to the Superior Colliculus, where does it go?
Nuclei of CN iii, iv and vi
Motor nucleus of vii
Spinal cord
358
Where else does the Superior Colliculus receive inputs from?
Visual cortex
Frontal eye fields
Spinal cord
359
At what points in the visual pathway does decussation occur?
Optic chiasm
| Optic tracts carry contralateral info
360
What layers of the primary visual cortex form the visual association cortex?
Layers V2-V6
361
Where is layer V1 concentrated?
Calcarine sulcus
362
What gyrus are lower visual fields projected to?
The gyrus superior to the calcarine sulcus
363
Where does the macula project to in the visual cortex?
Posterior pole
364
What eye movements does the visual cortex provide?
Movements in response to visual stimuli:
- eg. Tracking a moving objext
- Smooth eye motions
365
What eye movements do the frontal eye fields provide?
Movements of command:
- Independent of moving stimuli
- Saccadic (jerky) eye motions
366
What is the direct pupillary light reflex?
When light is shone into one eye, the ipsilateral pupil constricts
367
What is the consensual pupillary light reflex?
When light is shone into one eye, the contralateral pupil also constricts
368
When light is shone into one eye, why do both pupils constrict?
Pretectal fibres project bilaterally to the Edinger-Westphal nucleus
369
The accommodation reflex requires inputs to what structures?
Oculomotor nucleus
| Edinger-Westphal nucleus
