Anatomy Flashcards
1
Q
What does the telencephalon form?
A
Cerebral hemispheres
2
Q
What does the diencephalon form?
A
Thalamus, hypothalamus
3
Q
What does the mesencephalon form?
A
Midbrain
4
Q
What does the metencephalon form?
A
Pons, cerebellum
5
Q
What does the myelencephalon form?
A
Medulla oblongata
6
Q
What is the brainstem?
A
Midbrain, pons and medulla oblongata
7
Q
What are the most numerous cells in the CNS?
A
Glial cells
8
Q
What roles are astrocytes involved in?
A
Support, maintaining the BBB, environmental homeostasis
9
Q
What do oligodendrocytes produce?
A
Myelin in the CNS (not PNS)
10
Q
Describe oligodendrocytes
A
Numerous branches that extend to produce internodes of myelin around axons. Round nucleus
11
Q
What are microglia?
A
Cells of similar lineage to macrophages (haemopoietic origin)- immune monitoring and antigen presentation
12
Q
What is the appearance of microglia in a resting state?
A
Elongated nucleus and have a number of short spiny cell processes
13
Q
What is the appearance of microglia in an activated state?
A
Become rounder and take on a similar appearance to macrophages
14
Q
What can activate microglia?
A
Bacteria infection
15
Q
What are the 4 major types of glial cells?
A
Astrocytes, oligodendrocytes, microglia, ependymal cells
16
Q
Describe ependymal cells
A
Ciliated cuboidal/columnar epithelium that lines the ventricles
17
Q
What is a folium?
A
Equivalent to a gyrus in the cerebral hemispheres
18
Q
What makes up the grey matter?
A
Huge numbers of neurons, cell processes, synapses and support cells
19
Q
What makes up the white matter?
A
Medullary centre- axons (most myelinated) and their support cells
20
Q
Where is the parietal lobe located?
A
Posterior to central sulcus, superior to lateral sulcus, and anterior to a line from parieto-occiptal sulcus to the preoccipital notch
21
Q
Where is the occipital lobe located?
A
Posterior to a line from the parieto-occipital sulcus to the preoccipital notch
22
Q
Where is the temporal lobe located?
A
Inferior to the lateral sulcus and posteirorly by a line from the parieto-occipital sulcus and the preoccipital notch
23
Q
What role does the insular lobe have?
A
Patient’s experience of pain
24
Q
What are the 3 meningeal layers?
A
Dura mater
Arachnoid space
Pia mater
25
What is contained within the arachnoid mater?
Subarachnoid space containing CSF
26
Where is the enteric nervous system found?
In digestive system from oesophagus to rectum
27
Where are the neurons of the ENS found?
Largely in two plexuses in the walls of the gut (myenteric plexus between outer layers of smooth muscle, submucosal plexus in submucosa)
28
What is the T4 spinal nerve segment identified by?
Male nipple
29
What is the T10 spinal nerve segment identified by?
Umbilicus
30
What does the C2-4 segment supply?
Posterior scalp, neck and shoulder
31
What does the C5-T1 segment supply?
Upper limb
32
What does the L2-Co1 segment supply?
Lower limb, gluteal region and perineum
33
What are nerve plexuses?
Networks of intertwined anterior rami
34
What makes up the cervical plexus?
C1-4 anterior rami
35
What does the cervical plexus supply?
Posterior scalp, neck wall and diaphragm
36
What makes up the brachial plexus?
C5-T1 anterior rami
37
What does the brachial plexus supply?
Upper limb
38
What does the lumbar plexus supply?
Lower limb
39
What makes up the lumbar plexus?
L1-4 anterior rami
40
What makes up the sacral plexus?
L5-S4 anterior rami
41
What does the sacral plexus supply?
Lower limb, gluteal region and perineum
42
What is the myotome of each spinal nerve?
The skeletal muscles supplied with motor innervation by both the anterior and posterior ramus of that spinal nerve
43
Where does the sympathetic tract exit the spinal cord?
T1-L2 spinal nerves
44
Where do sympathetic fibres synapse in the CNS?
Lateral horn of grey matter
45
What structure does the presynaptic sympathetic axon pass through from the spinal nerve to reach the paravertebral ganglion?
Rami communicans
46
What type of axons come from the anterior horn of the spinal cord?
Motor axons
47
What type of axons come from the posterior horn of the spinal cord?
Sensory axons
48
What is the tapered cone-shape in which the spinal cord terminates?
Conus medullaris
49
What does the conus medullaris continue as?
A thin connective tissue cord called the filum terminale
50
What is the filum terminale anchored to?
The dorsum of the coccyx
51
What is the ribbon of tissue on the lateral aspects of the cord which hold it in the canal?
Denticulate ligament
52
What is the denticulate ligament formed from?
Pial and arachnoid tissue
53
Where does the denticulate ligament attach?
To the dura at points along the length of the cord
54
What is the white matter of the spinal cord conventionally described as being made up of?
Posterior, lateral and anterior fasciculi
55
What is the grey matter of the spinal cord divided into?
Left and right posterior and anterior horns
56
What parts of the grey matter surround the central canal?
Dorsal and ventral commisures
57
What is found at spinal segments T1 to L2 which contains the preganglionic sympathetic neurons?
A smaller lateral horn
58
What is the arterial supply of the spinal cord?
Three major longitudinal arteries
Segmental arteries
Radicular arteries
59
What are the three major longitudinal arteries that supply the spinal cord?
One anterior and two posterior that originate from the vertebral arteries. Run along length of the cord
60
What are the segmental arteries derived from?
Vertebral, intercostal and lumbar arteries
61
Where do the radicular arteries travel?
The dorsal and ventral roots
62
Describe the venous drainage of the spinal cord
Follows a similar pattern to the supply, with both longitudinal and segmental veins
63
What is the epidural space?
The space between the dura and bone in the spinal canal
64
What does the epidural space contain?
Adipose tissue and the anterior and posterior epidural venus plexuses
65
What does the dorsal pathway control?
Fine touch and conscious proprioception (particularly from the upper limb)
66
Where do the fibres in the dorsal pathway cross?
Medulla
67
What does the STT control?
Pain, temperature, deep pressure
68
What does the corticospinal tract form on the anterior surface of the medulla?
Visible ridges referred to as pyramids- hence pyramidal tract
69
What can a CVA of the internal capsule result in?
A lack of descending control of the corticospinal tract which results in spastic paralysis with hyperflexion of the upper limbs- referred to as decorticate posturing
70
What is a general rule regarding fibres originating from the pons and medulla?
Fibres from pons facilitate extensor movements and inhibit flexor movements, while those from medulla to the opposite
71
Where is the cerebellum located?
Posterior and inferior cerebral hemispheres
72
What is the cerebellum attached to the brainstem by?
3 stalks termed peduncles:
| Superior, middle and inferior cerebellar peduncle
73
What are the 3 layers of the cerebellar cortex?
```
Molecular layer (outer)
Purkinje cell layer (middle)
Granular layer (inner)
```
74
What type of neuron projects to the cerebellum?
Afferent
75
Where do the important afferents to the cerebellum mainly arrive from?
```
Spinal cord (somatic proprioceptors and pressure receptors)
Cerebral cortex (via pons)
Vestibular apparatus (via vestibular nuclei)
```
76
Where do the afferent neurones mainly project to in the cerebellum?
Granule cell layer
77
What is the only output from the cerebellum?
Via the axons of Purkinje cells which mainly synapse on neurons of deep cerebellar nuclei- contribute to motor tract function of brainstem/cord
78
Where do most efferent axons of the deep cerebellar nuclei cross and synapse?
Midline and synapse in the thalamus- fibres than sent to the motor cortex
79
Cerebellar hemispheres influence what side of the body?
Ipsilateral
80
What can a unilayeral hemispheric lesion result in?
Disturbance of coordination in limbs. Can result in intention tremor and unsteady gait in the absence of weakness or sensory loss
81
What does bilateral cerebellar dysfunction result in?
Slowed, slurred speech, bilateral incoordination of arms and a staggering, wide based gait (cerebellar ataxia)
82
What does acute alcohol exposure cause in the cerebellum?
Bilateral cerebellar hemisphere dysfunction and presents with cerebellar ataxia
83
What will a midline cerebellar lesion cause?
Disturbance of postural control, but preserved limb coordination
84
What are the functions of the basal ganglia?
Facilitate purposeful movement
Inhibit unwanted movements
Role in posture and muscle tone
85
What are the components of the basal ganglia?
```
Striatum
Corpus striatum
Lenticular nucleus
Subthalamic nucleus
Substantia nigra
```
86
What makes up the lenticular nucleus?
Putamen
| Globus pallidus
87
What makes up the corpus striatum?
Caudate nucleus
Putamen
Globus pallidus
88
What makes up the striatum?
Caudate nucleus, putamen
89
What is the pathology of Parkinson's?
Degeneration of dopaminergic neurons of the substantia nigra
90
How do the basal ganglia work with the motor cortex to enhance normal movement?
There is a direct pathway between them which enhances outflow of the thalamus, thusly enhancing the desired movement
91
What issues the command to move?
Pyramidal neurones (under voluntary control)
92
How do the basal ganglia work with the motor cortex to suppress unwanted movement?
An indirect pathway inhibits the outflow of thalamus
93
What side of the body do unilateral lesions of the basal ganglia affect?
Contralateral
94
What do lesions of the basal ganglia cause?
Changes in muscle tone
| Dyskinesias: Tremor, chorea, myoclonus
95
What is the pathology of Huntington's?
Progressive degeneration of the basal ganglia and cerebral cortex
96
What do the extrinsic back muscles do?
Move the upper limb
97
What are the main extrinsic back muscles?
Trapezius
Lattimus dorsi
Levator scapulae
Rhomboids (major and minor)
98
What do the intrinsic back muscles do?
Maintain back posture and move the spine
99
What are the main intrinsic back muscles?
```
Erector spinae (superficial)
Transversospinalis (deep)
```
100
What makes up erector spinae?
3 vertically arranged muscle groups located just lateral to the spine
101
What do all the erector spinae muscle fibres attach inferiorly by?
A common tendon to the sacrum & the iliac crest
102
What do individual erector spinae muscle fibres attach superiorly to?
Via a tendon either:
a rib (between angle and tubercle)
a transverse process of a vertebra
a spinous process of a vertebra
103
Where is transversospinalis located?
Within the deep grooves between the transverse and spinous processes
104
Where do the inidividual muscle fibres of transversospinalis attach between?
A vertebra and the skull
A vertebra and a rib
One vertebra and another
A vertebra and the sacrum
105
What is extension of the spine a function of?
The intrinsic back muscles
106
What is spine flexion a function of?
Psoas major and rectus abdominus
107
What are the functions of the spine?
Support weight of the head and trunk in upright posture
Protect spinal cord (and nerves)
Allow movements
108
What are the pain signals of facet joints and IV discs transmitted via?
Posterior rami
109
What do the facet joints join?
Articular processes of 2 adjacent vertebrae
110
Where along the spine will you not find IV discs?
Between C1-2 and fused sacrum and coccyx
111
What ligaments run along the spine?
```
Ligamentum flavum
Posterior longitudinal ligament
Anterior longitudinal ligament
Supraspinous ligament
Interspinous ligament
```
112
What does the ligamentum flavum connect?
Adjacent laminae posterior to spinal cord
113
Where do the anterior and posterior longitudinal ligaments attach?
To the anterior and posterior aspects of all vertebral bodies and intervertebral discs respectively
114
What do the anterior and posterior longitudinal ligaments prevent?
Over extension and over flexion of the spine respectively
115
What does the supraspinous ligament connect?
Tips of spinous processes
116
What does the interspinous ligament connect?
Superior and inferior surfaces of adjacent spinous processes
117
What do all cervical vertebrae have in the transverse process?
A foramen for vertebral arteries
118
What does C1 have instead of a body or spinous process?
An anterior and posterior arch
119
Where are the atlanto-occipital joints between?
The occipital condyles and the superior articular facets of the atlas
120
What type of joints are the atlanto-axial joints?
Synovial (3)
121
Where are the atlanto-axial joints located?
2 between the inferior articular facets of atlas and superior articular facets of axis
1 between anterior arch of atlas and odontoid process of axis
122
What are the main movements of the atlanto-axial joints?
Rotations
123
What foraminae are present in the sacrum instead of intervertebral foraminae?
Anterior and posterior sacral foraminae
124
Where is local anaesthetic injected in caudal anaesthesia to anaesthetise the sacral spinal nerve roots of the cauda equina?
Sacral hiatus
125
Where is the spinal cord located?
From C1-L2. Continuous with medulla oblongata at foramen magnum
126
What is located in the L1 dermatome?
Groin
127
What is located in the L2 dermatome?
Anterior thigh
128
What is located in the L3 dermatome?
Anterior knee
129
What is located in the L4 dermatome?
Medial malleolus
130
What is located in the L5 dermatome?
Dorsum of foot
131
What is located in the S1 dermatome?
Heel
132
What is located in the S2 dermatome?
Posterior knee
133
What is located in the S3 dermatome?
Buttock
134
What is located in the S4 dermatome?
Perineum
135
What is located in the S5 dermatome?
Perianal skin
136
What happens when a dermatome is tested for sensory function (T10 example)?
Stimulation in anterior aspect of right T10 dermatome
AP generated by receptors in segment
AP continues along axons to anterior ramus
Then to T10 spinal nerve
Then to T10 posterior root
Then to T10 posterior rootlets
Then to posterior horn of spinal cord
137
What are the spinal nerve root levels of the femoral nerve?
L2,3,4
138
What supplies the neck and scalp skin posteriorly?
Posterior rami of spinal nerves C2-8
139
What supplies the skin of the neck anterolaterally?
Named sensory branches of the cervical plexus (anterior rami of C1-4 spinal nerves)
140
Describe lesser occipital nerve
Spinal nerve C2
| Skin posterior to external ear
141
Describe great auricular nerve
Spinal nerve C2,3
| Skin over the angle of the mandible & some of the external ear
142
Describe transverse cervical
Spinal nerve C2,3
| Skin over anterior neck
143
Describe the supraclavicular nerves
Spinal nerve C3,4
| Skin over the clavicle and shoulder tip
144
What supplies the upper anterolateral trunk wall?
Intercostal nerves (anterior rami of spinal nerves T2-11)
145
What supplies the lower anterolateral trunk wall?
Iliohyogastric & the iliolingual nerves (formed from bifurcation of anterior ramus of L1 spinal nerve)
146
What supplies the T12 dermatome of the trunk?
The subcostal nerve (anterior ramus of T12 spinal nerve)
147
What are the posterior parts of the back dermatomes supplied by?
Posterior rami
148
Describe the axillary nerve
C5,6
| Badge patch
149
Describe the supraclavicular nerves
C3,4
| Anterior arm, shoulder
150
Describe the radial nerve
C5,6,7,8,T1
Lateral arm
Posterior hand
151
Describe the cutaneous branch of the musculocutaneous nerve
C5,6,7
| Inferolateral arm
152
Describe the ulnar nerve
C7,8,T1
| Medial hand
153
Describe the median nerve
C5,6,7,8,T1
| Lateral hand
154
What supplies the anatomical snuff box?
Cutaneous branches of the radial nerve
155
What happens when a named nerve is tested for sensory function (femoral nerve function)?
Stimulation in area innervated by femoral nerve
AP generated by receptors in that area (L2 dermatome)
AP continues along axons weaving through lumbar plexus
AP continues to L2 anterior rami
AP continues to L2 spinal nerve
AP continues to L2 posterior root
AP continues to L2 posterior rootlets
AP continues into posterior horn of spinal cord
156
What do the cervical plexus motor axons supply?
Neck postural and strap muscles
| Diaphragm
157
What do the brachial plexus motor axons supply?
Muscles of the upper limb
| Extrinsic back muscles
158
What do the T2-L3 motor axons supply?
Postural back muscles
Intercostal muscles
Anterolateral abdominal wall muscles
159
Through what nerves are the anterolateral abdominal wall muscles supplied?
Thoracoabdominal, subcostal, iliohypogastric and iliolingual nerves
160
What do the lumbosacral plexus motor axons supply?
Lower limb muscles
| Perineal skeletal muscles
161
What innervates the muscles of facial expression?
CNVII
162
What innervates the muscles of mastication?
CNV3
163
What innervates the muscles of the tongue?
CNXII
164
What innervates the muscles of the soft palate?
CNX/pharyngeal plexus
165
What innervates neck postural muscles?
Posterior rami of cervical spinal nerves
166
What innervates the strap muscles?
Cervical plexus
167
What innervates the diaphragm?
Phrenic nerve (C3,4,5)
168
What innervates sternocleidomastoid & trapezius?
CNXI
169
What innervates the muscles of the pharynx?
CNX
170
What innervates the intrinsic muscles of the larynx ?
CNX
171
What inervates the intercostal muscles?
Intercostal nerves
172
What innervates the anterolateral abdominal wall muscles?
Thoracoabdominal nerves
173
What innervates erector spinae and transversospinalis groups?
Posterior rami of spinal nerves
174
What innervates deltoid and teres minor?
Axillary nerve
175
What innervates the anterior compartment of the arm?
Musculocutaneous nerve: C5,6,7
Biceps brachii
Brachialis
Coracobrachialis
176
What innervates the anterior compartment of the forearm and hand muscles?
Median nerve: (C5), C6,7,8,T1
Muscles of the anterior compartment of forearm:
The pronator muscles (Teres & Quadratus)
Flexor carpi radialis
Palmaris longus
Flexor digitorum superficialis
Lateral half of flexor digitorum profundus
Flexor pollicis longus
Muscles of the hand:
Thenar muscles
Lumbricals 1&2
177
What dos the radial nerve innervate in the upper limb (motor)?
Muscle of the posterior compartment of arm: Triceps brachii
Muscles of the posterior compartment of forearm: Brachioradialis
Supinator
ALL the extensors of the carpus & digits
Abductor pollicis longus
178
What does the ulnar nerve innervate in the upper limb(motor)?
Muscles of the anterior compartment of forearm:
Flexor carpi ulnaris
Medial half of flexor pollicis longus
Adductor pollicis
Muscles of the hand:
Hypothenar muscles, Lumbricals 3&4
& ALL the interossei (dorsal & palmar)
179
What does the femoral nerve innervate in the lower limb (motor)?
Quadriceps femoris, sartorius and pectineus
180
What does the sciatic nerve innervate in the lower limb (motor)?
```
Tibial part: L4-S3
muscles of the posterior compartment of leg:
true hamstrings -
semimembranosus
semitendinosus
long head of biceps femoris
muscles of the posterior compartment of leg:
gastrocnemius
soleus
plantaris
popliteus
tibialis posterior
flexors of the digits (digitorum & hallucis longus)
muscles of the sole of the foot:
ALL intrinsic muscles of the sole of the foot
common fibular part: L4-S2
short head of biceps femoris
```
181
What does the obturator nerve (L2-4) innervate in the lower limb (motor)?
```
All of the medial compartment of thigh
All adductors (Brevis/longus/magnus) and gracilis
```
182
What does the common fibular nerve innervate in the lower limb (Motor)
Superficial fibular branch:
muscles of the lateral compartment of leg:
fibularis longus & brevis
```
Deep fibular branch:
muscles of the anterior compartment of leg:
fibularis longus & brevis
muscles of the dorsum of the foot:
extensor digitorum brevis (EDB)
extensor hallucis brevis (EHB)
```
183
What is tested in shoulder joint movement?
Abduction: C5 deltoid
Adduction: C7 Pectoralis major and latissumus dorsi
184
What is tested in elbow joint movement?
Flexion: C5,6 Biceps brachii
Extension: C7,8 triceps brachii
Pronation: C6 pronator teres and quadratus
Supination: C8 supinator
185
What is tested in wrist joint movement?
Flexion: C6,7 (flexors of carpus)
Extension: C7,8 (extensors of carpus)
186
What is tested in finger joint movement?
Flexion: C8 (flexors of digits)
Extenson: C7 (extensors of digits)
Abduction: T1 (palmar interossei)
Adduction: T1 (dorsal interossei)
187
What is tested in hip joint movement?
Flexion: L2,3 (psoas major)
Extension: L5,S1 (gluteus maximum and hamstrings)
188
What is tested in knee joint movement?
Flexion: L5,S1 (hamstrings)
Extension: L3,4 (quadriceps)
189
What is tested in ankle joint movement?
Dorsiflexion: L4,5 (tibialis anterior)
Plantar flexion: S1,2 (gastrocnemius/soleus)
Inversion: L4 (tibialis anterior and posterior)
Eversion: L5,S1 (fibularis longus and brevis)
190
What happens when a spinal nerve myotome is tested for motor function (L3 spinal cord segment)?
APs generated by voluntary intention in primary somatosensory cortext
Conducted via UMN axons of corticospinal tract
Continues along axons to anterior horn L3 spinal cord
UMN synapse with L3 LMN stimulating AP
AP continues along axons to L3 spinal nerve
Then to either L3 posterior or anterior ramus
APS via L3 anterior rami often weave through the lumbar plexus via named nerve
Then reach NMJ of supplied muscle
191
What happens in the spinal cord reflex of the knee jerk?
Briskly tap the patellar tendon (ligament) with a tendon hammer
The tap applies stretch to the quadriceps muscle fibres via the quadriceps tendon
The quadriceps muscle spindles (stretch receptors) initiate APs in the anterior rami axons within the femoral nerve
These sensory APs are conducted to the dorsal horn of, predominantly, spinal cord segment L4
The axons then pass into the anterior horn to synapse upon the LMNs that supply quadriceps
The APs conducted via the LMN axons in the femoral nerve reach the quadriceps neuromuscular junctions
The muscle contracts to bring about extension of the knee joint
192
What are descending tracts important in regarding muscle contractions?
Modulating reflex contractions
193
What can loss of descending controls, such as with a UMN lesion e.g. CVA, result in?
Increased stretch reflexes and spasticity
194
What reflexes are tested?
```
Biceps Brachii- C5(6)
Triceps Brachii- C7
Brachioradialis- C6
Knee Jerk- L4
Ankle Jerk- S1
```
195
Where do cranial nerves exit the brain?
Anteriorly except CN IV
196
What are the sensory cranial nerves?
1,2,8
197
What are the motor cranial nerves?
3,4,6,11,12
198
What cranial nerves are mixed motor and sensory?
5,7,9,10
199
What will motor components of cranial nerves be associated with?
Motor nuclei
200
Where will the soma of sensory nerve cells be found?
In ganglia outside of the CNS (analogous to the DRGs for the spinal nerves)
201
What is the only sensory modality that does not synapse in the thalamus prior to reaching the cortex?
CN 1
202
Where are the nuclei for CN 3,4,6 found near?
Midline of the brainstem
203
Where is the nucleus of the oculomotor nerve located?
Superior colliculus of the midbrain
204
What type of nerve fibres are contained within CNIII?
Somatic motor + p.symp
205
Where is the nucleus of the trochlear nerve located?
Inferior colliculus of the midbrain
206
What type of nerve fibres are contained within CNIV?
Somatic motor
207
Where is the nucleus of the abducens nerve located?
In the pons at the floor of the 4th ventricle
208
What type of nerve fibres are contained within CNVI?
Somatic motor
209
What type of nerve fibres are contained within CNXII?
Somatic motor
210
Where is the nucleus of the hypoglossal nerve located?
Medulla
211
Where does the spinal accessory nerve arise from?
Cervical spinal cord
212
What are the functions of CNV5?
Somatosensation of face:discriminative touch, vibration, pain, temperature
Proprioception of chewing
Motor control- muscles of mastication, tensor tympani, mylohyoid, ant. belly of digastric, tensor veli palatini
213
Where is the trigeminal nerve sensory nucleus located?
From midbrain down to upper 2 segments of spinal cord- 3 parts, separated by function
214
What is the function of the mesencephalic nucleus of CNV?
Proprioception info from chewing muscles
215
What is the function of the pontine trigeminal nucleus of CNV?
Principle nucleus- discriminative touch, vibration
216
What is the function of the spinal nucleus of CNV?
Pain, temperature
217
What is unusual about the mesencephalic nucleus?
It is the only site in the CNS where the cell bodies of primary afferent neurons live inside the CNS
218
Where is the motor nucleus of CNV located?
Pons
219
What are the functions of CNVII?
Motor (muscles of mastication, stapedius)
Parasymp. innervation to pterygopalatine and submandibular ganglia
Taste (anterior 2/3 of tongue via c. tympani).
220
What are the functions of CNIX?
Tactile sense, pain and temperature from the posterior tongue, pharyngotympanic tube and upper pharynx.
Taste (posterior 1/3 of the tongue).
Parasympathetic fibres to the otic ganglion (parotid gland).
Motor (one muscle: stylopharyngeus)
221
What are the functions of CNX?
Tactile sense, pain and temperature from the pharynx, larynx, trachea, oesophagus and thoracic and abdominal viscera.
Taste (epiglottis)
Parasympathetic innervation to ganglia serving thoracic and abdominal viscera.
Motor (striated muscle of the pharynx and larynx) (cranial accessory contributes to this function).
222
Where is the facial nerve nucleus located?
Caudal pons (3 parts)
223
What are the 3 parts of the facial nerve nucleus?
Facial motor nucleus
Sup. salivatory (ps)
Solitary nucleus (taste)
224
Where is the glossopharyngeal nerve nucleus located?
Upper medulla (4 components)
225
What are the 4 components of the glossopharyngeal nerve nucleus?
```
Solitary nucleus (taste)
Commissural (visceral)
Inferior salivatory (ps)
Nucleus ambiguous (stylopharyngeus muscle)
```
226
Where is the vagus nerve nucleus located?
Upper medulla (4 components)
227
What are the 4 components of the vagus nerve nucleus?
Solitary nucleus (taste)
Commissural (visceral)
Dorsal motor nucleus (ps)
Nucleus Ambiguus (motor)
228
What nucleus is shared by CN VII, IX and X?
Solitary nucleus (taste and visceral sensory information)
229
What nucleus is shared by CN VII, IX?
Inf. and Sup. Salivatory nuclei (parasympathetic efferents to ganglia of salivary glands and pterygopalatine ganglion)
230
What nucleus is shared by CN IX and X (and cranial part of XI?
Nucleus ambiguus (motor efferents to muscles of pharynx and larynx)
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What shape do the solitary and commissural nucleus form?
V shape
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What is the corticobulbar tract?
Part of the pyramidal tract that is motor to cranial nerves
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Where does the input to CN's containing parasymp efferents (VII, IX, X) mainly come from?
Hypothalamus whose efferents reach the preganglionic autonomic neurons both directly and via synapses in the reticular formation
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What is the reticular formation?
A network of loosely aggregated cells with cell bodies, axons and dendrites intermingling in the central core of the brainstem.
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What are the functions of the reticular formation?
Integrate cranial nerve reflexes
Participate in conduction and modulation of pain.
Influence voluntary movement
Regulate autonomic activity.
Integrate some basic functions, like respiration and sleep
Activate the cerebral cortex: major component of the Ascending Reticular Activating System
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Where do CN VI, VII, VIII exit?
At the pontomedullary junction
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What is the extracranial part of CNI?
Within olfactory mucosa in nasal cavity
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What is the cranial foramina of CNI?
Cribriform plate of ethmoid bone-anterior cranial fossa
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What is the intracranial part of CNI?
Olfactory nerves synapse in olfactory bulb
| Then pass though the olfactory tract to cortical areas
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What is the extracranial part of CNII?
Neurons of retina travel posteriorly via optic nerve from posterior hemisphere of eye through orbit
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What is the cranial foramina of CNII?
Optic canal in middle cranial fossa
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What is the intracranial part of CNII?
Travels around pituitary stalk to optic chiasm to form optic tract. Connects with diencephalon
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How is CNI tested?
Ask patient to smell familiar smell while covering contralateral nostril
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How is CNII tested?
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Acuity (Snellen)
Colour (Ishihara plates-colour blindness)
Fields (quadrants)
Reflexes (corneal, pupillary light)
Fundoscopy
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What is the extracranial part of CNIII?
Passed through SOF into orbit (parasymps synapse in ciliary ganglion)
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What is the cranial foramina of CNIII?
SOF
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What is the intracranial part of CNIII?
Connects at midbrain
| Travels towards orbit in lateral wall of cavernous sinus
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What is the extracranial part of CNIV?
Passed through SOF into orbit
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What is the cranial foramina of CNIV?
SOF
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What is the intracranial part of CNIV?
Connects with midbrain. Travels towards orbit in lateral wall of the cavernous sinus
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What is the extracranial part of CNVI?
Passed through SOF into orbit
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What is the cranial foramina of CNVI?
SOF
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What is the intracranial part of CNVI?
Connects at pontomedullary junction. Travels towards orbit within cavernous sinus
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What is the extracranial part of CNVIII?
Axons from cochlear and vestibular apparatus
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What is the cranial foramina of CNVIII?
IAM in posterior cranial fossa
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What is the intracranial part of CNVIII?
Travels posteromedially from the IAM to the pontomedullary junction.
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What is the extracranial part of CNXI?
Axons supply sternocleidomastoid (SCM) on deep surface, then continue across the posterior triangle to supply trapezius and (SCM)
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What is the cranial foramina of CNXI?
Jugular foramen In posterior cranial fossa
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What is the intracranial part of CNXI?
Connects with cervical spinal cord. Ascends through foramen magnum then travels towards jugular foramen
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How is CNXI tested?
Ask patients to shrug shoulders
| Ask them to turn head to flex neck and turn towards opposite side
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Where do the cutaneous nerves of the cervical plexus pass deep to?
Midpoint of the posterior border of SCM, but not trapezius
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What is the extracranial part of CNXII?
Desends lateral to carotid sheath
At level of hyoid turns anteriorly towards lateral aspect of tongue
Supplies most muscles of tongue
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What is the cranial foramina of CNXII?
Hypoglossal canal (pcf)
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What is the intracranial part of CNXII?
Connects via many rootlets lateral to the pyramids of medulla oblongata. Passes anteriorly to hypoglossal canal
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What does CN XII innervate?
All -glossus muscles except palatoglossus (genio/stylo/hyoglossus and intrinsic tongue muscles)
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How is CNXII tested?
Ask patient to stick tongue straight out
If both CNXII's are functioning normally the tongue tip remains in the midline on protrusion
If unilateral CNXII pathology tongue points towards side of injury
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Which division of CNV is sensory and motor?
V3-mandibular
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What is the extracranial part of CNV?
Sensory axons from all 3 divisions course, from superficial and deep structures, posteriorly, towards their foramen
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What is the cranial foramina of CNV?
V1-SOF
V2-Foramen rotundum
V3-Foramen ovale
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What is the intracranial part of CNV?
Inferior to edge of tentorium cerebelli between posterior and middle cranial fossa. Connects with pons
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What does CNV1 supply?
- The upper eyelid
- The cornea (corneal reflex)
- All the conjunctiva
- Skin of the root/bridge/tip of the nose
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What does CNV2 supply?
- The skin of the lower eyelid
- The skin over the maxilla
- The skin of the ala of the nose
- The skin/mucosa of the upper lip
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What does CNV3 supply (superficial sensory)?
- Skin over the mandible and temporomandibular joint
| apart from the angle of the mandible – supplied by C2,3 spinal nerves
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What is the deep sensory territory of CNV1?
Bones & soft tissues of the orbit (except the orbital floor & lower eyelid)
Upper anterior nasal cavity
Paranasal sinuses (except the maxillary sinus)
Anterior & posterior cranial fossae
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What is the deep sensory territory of CNV2?
Lower posterior nasal cavity
Maxilla & maxillary sinus
Floor of the nasal cavity/palate
Maxillary teeth & associated soft tissues (gingivae & mucosae)
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What is the deep sensory territory of CNV3?
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Middle cranial fossa
Mandible
Anterior 2/3rds of the tongue
Floor of the mouth
Buccal mucosa
Mandibular teeth & associated soft tissues
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What does CNV3 supply (motor)?
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Masseter
Temporalis
Medial pterygoid
Lateral pterygoid
Tensor veli palatine
Tensor tympani
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How is the sensory component of CNV tested?
Ask patient to close eyes
Brush skin in each dermatome with cotton wool
Ask patient to tell you when they feel skin being touched
Compare 2 sides
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How is the motor component of CNV tested?
Palpate strength of contraction of masseter and temporalis by asking patient to clench teeth
Ask patient to open their jaw against resistance
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What is the extracranial part of CNVII?
Most somatic motor axons pass into the parotid gland then into 1 of the 5 branches that supply the muscles of facial expression
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What is the cranial foramen of CNVII?
Temporal bone- IAM (in), stylomastoid foramen (out)
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What is the intracranial part of CNVII?
Directly into IAM in the pcf. Connects anterolateral to pontomedullary junction
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What does the chorda tympani do?
Taste buds of anterior 2/3 tongue
| Parasymp supply to submandibular/lingual glands
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What supplies stapedius?
CNVII
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What are the muscles of facial expression?
Frontalis, orbicularis oculi, elevators of lips, orbicularis oris
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How can the motor function of CNVII be tested?
Raise eyebrows
Close eyes tightly
Smile
Puff out cheeks and hold air
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What types of nerve make up CNIX?
Special sensory (Taste), Sensory, Motor, Visceral afferent and Parasympathetic
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What is the intracranial part of CNIX?
Directly towards jugular foramen in pcf. Connects with lateral aspect of superior medulla oblongata
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What is the extracranial part of CNIX?
Descends towards pharynx and mouth to stylopharyngeus, parotid gland, pharyngeal mucosa, carotid body and sinus, posterior 1/3 of tongue
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What is the cranial foramen of CNIX?
Jugular foramen
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What does CNIX provide the general sensory supply of?
The posterior 1/3rd of the tongue
The mucosa of most of the nasopharynx and oropharynx
The mucosa of some of the laryngopharynx (some overlap with CN X territory)
The palatine tonsil
The eustachian tube
The middle ear cavity
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What does CNIX provide the special sensory supply of?
Vallate papillae of posterior 1/3 tongue
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What does CNIX provide the visceral afferent supply of?
Carotid sinus baroreceptors and carotid body chemoreceptors
294
What does CNIX provide the somatic motor supply of?
Stylopharyngeus
295
What does CNIX provide the parasym supply of?
Parotid gland
296
What nerve axons form the afferent limb of the gag reflex?
CNIX
297
What is the cranial foramen of CNX?
Jugular foramen
298
What is the intracranial part of CNX?
Directly towards jugular foramen in pcf. Connects with lateral aspect of medulla oblongata, immediately inferior to CNIX
299
What is the extracranial part of CNX?
Axons supply lots of structures between palate and midgut
300
What types of nerve are involved in CNX?
Sensory, Motor, Visceral afferent and Parasympathetic
301
Where does CNX travel within the neck?
Within the carotid sheath, posterior to and between the common carotid artery and IJV
302
Where do the recurrent laryngeal nerves curve under?
Left: arch of aorta
Right: right subclavian artery
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What branches of CNX exist in the abdomen?
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Both CNs X pass onto stomach surface
Celiac and superior mesenteric ganglia
Splenic branches
Pancreatic branches
Foregut branches
Midgut branches
Renal branches
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Where do the very last ps axons of CNX pass to?
The splenic flexure of the colon
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How is CNX tested?
Patient says 'ah' (palate muscles)
Uvula goes to functioning side if unilateral pathology
Patient swallows water (pharyngeal muscles)
Larynx movement, splutter may suggest abnormality
Listen to speech (laryngeal muscles)
Hoarseness may indicate abnormality
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What are the 5 layers of the scalp?
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Skin
Connective tissue
Aponeurosis
Loose connective tissue
Pericranium
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Where are the named arteries of the scalp located?
Layer 2- connective tissue
308
What do the scalp arteries form just deep to the skin?
An anastomotic network
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Where does the middle meningeal artery course over?
The deep aspect of the pterion
310
What are the layers of the meninges?
Dura mater- tough/fibrous. Sensory from CNV, enclodes dural venous sinuses
Arachnoid mater- arachnoid granulations (reabsorb CSF)
Subarachnoid space
Pia mater- adherent to brain and vessels entering or leaving brain
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What is the diaphragm sellae?
A tough sheet of dura mater forming a roof over the pituitary fossa
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What is the tentorium cerebelli?
Tough sheet of dura mater tenting over cerebellum
Attaches to ridges of petrous temporal bones
Central gap to permit the brainstem to pass through
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What is the falx cerebri?
Midline structure made of dura mater
Attaches to deep aspect of skull: crista galli of ethmoid bone anteriorly
internal aspect of sagittal suture
internal occipital protruberane of occipital bone posteriorly
Separates hemispheres
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What is the venous drainage of the brain?
Facial vein
Ophthalmic veins
Cavernous sinuses
Cerebral veins
Drain into superior and inferior sagittal sinuses
They drain into the sigmoid sinuses which drains into the IJV
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What is the arterial supply to the brain?
Vertebral arteries
| Internal and external carotids
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What contains arterial branches supplying the brainstem and cerebellum?
Circle of Willis
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Where is the circle of Willis located?
Inferior to midbrain, closely related to pituitary stalk and optic chiasm, within the subarachnoid space
318
Where is CSF reabsorbed?
Dural venous sinuses via arachnoid granulations
319
Where can the subarachnoid space be accessed?
Via LP at L3/4 or L4/5 IV disc levels
320
Where does the subarachnoid space end?
At the level of the S2 part of the sacrum
321
What causes hydrocephalus?
Excessive production, obstruction to flow or inadequate reabsorption leads to an increased CSF volume
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What may cause an extradural haemorrhage?
Ruptured MMA- trauma to pterion
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What may cause a subdural haemorrhage?
Torn cerebral veins- falls in elderly
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What may cause a subarachnoid haemorrhage?
Ruptured circle of Willis (berry) aneurysm
| Congenital aneurysm
325
In epidural anaesthesia and an LP, where does the catheter/needle pass through?
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Both through:
supra-, then interspinous ligaments
Ligamental flavum
Epidural space (fat and veins)
Needle continues on to:
Through dura and arachnoid mater to obtain CSF
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What can result in an epidural haematoma compressing spinal cord and cauda equine?
Damage to the extradural venous plexus
327
Where is the needle for an LP most safely inserted?
Where the SA space surrounds the cauda equine, not spinal cord
Where the vertebrae are not fused
328
When should a LP not be performed?
In cases of raised ICP
329
Describe the fibres superior to the cochlear nuclei
Some are crossed and some are not, therefore input above this level is essentially bilateral
330
What are the superior olivary nucleus and nucleus of lateral lemniscus important in?
Sound localisation and as relays for stapedial and tensor tympany reflexes
331
What type of organisation is present in the auditory cortex?
Tonotopic- low frequency at anterolateral part, high frequency at posteromedial part
332
What happens if Broca's area is damaged?
Patient's have difficulty in producing language, often using few words and only saying the most important words in a sentence. Don't usually have difficulty comprehending language. Known as Broca's, motor or expressive aphasia
333
What happens if Wernicke's area is damaged?
Patient’s have difficulty comprehending language. These patients can manifest defects ranging from words out of order to meaningless words.
Known as Wernicke's, sensory or receptive aphasia
334
What does maintenance of equilibrium use information from?
Vision, proprioception, vestibular apparatus
335
What areas of the brain receive vestibular input?
Posterior insula, region of parietal lobe just posterior to the postcentral gyrus and midway between apex of brain and lateral fissure
336
What do the superior colliculi provide output to?
Nuclei of CNIII, IV and VI, and motor nucleus of VII, and spinal cord
337
Where does the lower visual field project to?
The gyrus superior to the calcarine sulcus
338
Where does the upper visual field project to?
The gyrus inferior to the calcarine sulcus
339
Where does the macula project to?
The posterior pole of the visual cortex and occupies a much greater proportion of the cortex relative to the size of the visual field it covers
340
What roles do the visual cortex and frontal eye fields have in eye movement?
Visual cortex- provides for movements in response to visual stimuli, such as tracking moving objects
Frontal eye fields- control movements of command, as in movements that are independent of moving visual stimuli
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What does the accommodation reflex require input to?
Oculomotor and Edinger-Westphal nucleus from the visual cortex
