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Flashcards in Anatomy Deck (341):
1

What does the telencephalon form?

Cerebral hemispheres

2

What does the diencephalon form?

Thalamus, hypothalamus

3

What does the mesencephalon form?

Midbrain

4

What does the metencephalon form?

Pons, cerebellum

5

What does the myelencephalon form?

Medulla oblongata

6

What is the brainstem?

Midbrain, pons and medulla oblongata

7

What are the most numerous cells in the CNS?

Glial cells

8

What roles are astrocytes involved in?

Support, maintaining the BBB, environmental homeostasis

9

What do oligodendrocytes produce?

Myelin in the CNS (not PNS)

10

Describe oligodendrocytes

Numerous branches that extend to produce internodes of myelin around axons. Round nucleus

11

What are microglia?

Cells of similar lineage to macrophages (haemopoietic origin)- immune monitoring and antigen presentation

12

What is the appearance of microglia in a resting state?

Elongated nucleus and have a number of short spiny cell processes

13

What is the appearance of microglia in an activated state?

Become rounder and take on a similar appearance to macrophages

14

What can activate microglia?

Bacteria infection

15

What are the 4 major types of glial cells?

Astrocytes, oligodendrocytes, microglia, ependymal cells

16

Describe ependymal cells

Ciliated cuboidal/columnar epithelium that lines the ventricles

17

What is a folium?

Equivalent to a gyrus in the cerebral hemispheres

18

What makes up the grey matter?

Huge numbers of neurons, cell processes, synapses and support cells

19

What makes up the white matter?

Medullary centre- axons (most myelinated) and their support cells

20

Where is the parietal lobe located?

Posterior to central sulcus, superior to lateral sulcus, and anterior to a line from parieto-occiptal sulcus to the preoccipital notch

21

Where is the occipital lobe located?

Posterior to a line from the parieto-occipital sulcus to the preoccipital notch

22

Where is the temporal lobe located?

Inferior to the lateral sulcus and posteirorly by a line from the parieto-occipital sulcus and the preoccipital notch

23

What role does the insular lobe have?

Patient's experience of pain

24

What are the 3 meningeal layers?

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)

231

What shape do the solitary and commissural nucleus form?

V shape

232

What is the corticobulbar tract?

Part of the pyramidal tract that is motor to cranial nerves

233

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

234

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.

235

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

236

Where do CN VI, VII, VIII exit?

At the pontomedullary junction

237

What is the extracranial part of CNI?

Within olfactory mucosa in nasal cavity

238

What is the cranial foramina of CNI?

Cribriform plate of ethmoid bone-anterior cranial fossa

239

What is the intracranial part of CNI?

Olfactory nerves synapse in olfactory bulb
Then pass though the olfactory tract to cortical areas

240

What is the extracranial part of CNII?

Neurons of retina travel posteriorly via optic nerve from posterior hemisphere of eye through orbit

241

What is the cranial foramina of CNII?

Optic canal in middle cranial fossa

242

What is the intracranial part of CNII?

Travels around pituitary stalk to optic chiasm to form optic tract. Connects with diencephalon

243

How is CNI tested?

Ask patient to smell familiar smell while covering contralateral nostril

244

How is CNII tested?

Acuity (Snellen)
Colour (Ishihara plates-colour blindness)
Fields (quadrants)
Reflexes (corneal, pupillary light)
Fundoscopy

245

What is the extracranial part of CNIII?

Passed through SOF into orbit (parasymps synapse in ciliary ganglion)

246

What is the cranial foramina of CNIII?

SOF

247

What is the intracranial part of CNIII?

Connects at midbrain
Travels towards orbit in lateral wall of cavernous sinus

248

What is the extracranial part of CNIV?

Passed through SOF into orbit

249

What is the cranial foramina of CNIV?

SOF

250

What is the intracranial part of CNIV?

Connects with midbrain. Travels towards orbit in lateral wall of the cavernous sinus

251

What is the extracranial part of CNVI?

Passed through SOF into orbit

252

What is the cranial foramina of CNVI?

SOF

253

What is the intracranial part of CNVI?

Connects at pontomedullary junction. Travels towards orbit within cavernous sinus

254

What is the extracranial part of CNVIII?

Axons from cochlear and vestibular apparatus

255

What is the cranial foramina of CNVIII?

IAM in posterior cranial fossa

256

What is the intracranial part of CNVIII?

Travels posteromedially from the IAM to the pontomedullary junction.

257

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)

258

What is the cranial foramina of CNXI?

Jugular foramen In posterior cranial fossa

259

What is the intracranial part of CNXI?

Connects with cervical spinal cord. Ascends through foramen magnum then travels towards jugular foramen

260

How is CNXI tested?

Ask patients to shrug shoulders
Ask them to turn head to flex neck and turn towards opposite side

261

Where do the cutaneous nerves of the cervical plexus pass deep to?

Midpoint of the posterior border of SCM, but not trapezius

262

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

263

What is the cranial foramina of CNXII?

Hypoglossal canal (pcf)

264

What is the intracranial part of CNXII?

Connects via many rootlets lateral to the pyramids of medulla oblongata. Passes anteriorly to hypoglossal canal

265

What does CN XII innervate?

All -glossus muscles except palatoglossus (genio/stylo/hyoglossus and intrinsic tongue muscles)

266

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

267

Which division of CNV is sensory and motor?

V3-mandibular

268

What is the extracranial part of CNV?

Sensory axons from all 3 divisions course, from superficial and deep structures, posteriorly, towards their foramen

269

What is the cranial foramina of CNV?

V1-SOF
V2-Foramen rotundum
V3-Foramen ovale

270

What is the intracranial part of CNV?

Inferior to edge of tentorium cerebelli between posterior and middle cranial fossa. Connects with pons

271

What does CNV1 supply?

- The upper eyelid
- The cornea (corneal reflex)
- All the conjunctiva
- Skin of the root/bridge/tip of the nose

272

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

273

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)

274

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

275

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)

276

What is the deep sensory territory of CNV3?

Middle cranial fossa
Mandible
Anterior 2/3rds of the tongue
Floor of the mouth
Buccal mucosa
Mandibular teeth & associated soft tissues

277

What does CNV3 supply (motor)?

Masseter
Temporalis
Medial pterygoid
Lateral pterygoid
Tensor veli palatine
Tensor tympani

278

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

279

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

280

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

281

What is the cranial foramen of CNVII?

Temporal bone- IAM (in), stylomastoid foramen (out)

282

What is the intracranial part of CNVII?

Directly into IAM in the pcf. Connects anterolateral to pontomedullary junction

283

What does the chorda tympani do?

Taste buds of anterior 2/3 tongue
Parasymp supply to submandibular/lingual glands

284

What supplies stapedius?

CNVII

285

What are the muscles of facial expression?

Frontalis, orbicularis oculi, elevators of lips, orbicularis oris

286

How can the motor function of CNVII be tested?

Raise eyebrows
Close eyes tightly
Smile
Puff out cheeks and hold air

287

What types of nerve make up CNIX?

Special sensory (Taste), Sensory, Motor, Visceral afferent and Parasympathetic

288

What is the intracranial part of CNIX?

Directly towards jugular foramen in pcf. Connects with lateral aspect of superior medulla oblongata

289

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

290

What is the cranial foramen of CNIX?

Jugular foramen

291

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

292

What does CNIX provide the special sensory supply of?

Vallate papillae of posterior 1/3 tongue

293

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

303

What branches of CNX exist in the abdomen?

Both CNs X pass onto stomach surface
Celiac and superior mesenteric ganglia
Splenic branches
Pancreatic branches
Foregut branches
Midgut branches
Renal branches

304

Where do the very last ps axons of CNX pass to?

The splenic flexure of the colon

305

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

306

What are the 5 layers of the scalp?

Skin
Connective tissue
Aponeurosis
Loose connective tissue
Pericranium

307

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

309

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

311

What is the diaphragm sellae?

A tough sheet of dura mater forming a roof over the pituitary fossa

312

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

313

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

314

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

315

What is the arterial supply to the brain?

Vertebral arteries
Internal and external carotids

316

What contains arterial branches supplying the brainstem and cerebellum?

Circle of Willis

317

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

322

What may cause an extradural haemorrhage?

Ruptured MMA- trauma to pterion

323

What may cause a subdural haemorrhage?

Torn cerebral veins- falls in elderly

324

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?

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

326

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

341

What does the accommodation reflex require input to?

Oculomotor and Edinger-Westphal nucleus from the visual cortex