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Flashcards in Neuroanatomy Deck (164)
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1
Q

What are the major anatomical partitions of the nervous system?

A

Central and Peripheral

2
Q

What is in the CNS?

A

Brain and spinal cord

3
Q

What is in the PNS?

A

12 pairs of cranial nerves 31 pairs of spinal nerves and their branches

4
Q

What is formed from the prosencephalon?

A

Telencephalon and Diencephalon

5
Q

What is formed from the mesencephalon?

A

Mesencephalon

6
Q

What is formed from the rhombencephalon?

A

Metencephalon Mylencephalon

7
Q

what age does the neural tube form primary and secondary vesicles?

A

4 weeks 6-8 weeks

8
Q

What is the major derivative of the telencephalon?

A

Cerebral hemispheres

9
Q

What is the major derivative of the diencephalon?

A

Thalamus Hypothalamus

10
Q

What is the major derivative of the mesencephalon?

A

Midbrain

11
Q

What is the major derivative of the metencephalon?

A

Pons, cerebellum

12
Q

What is the major derivative of the myelencepalon?

A

Medulla oblongata

13
Q

What is the brainstem?

A

Combination of midbrain, pons and medulla oblongata is called the brainstem

14
Q

What are the principle cells of the CNS?

A

Neurons and Glial cells

15
Q

What are neurons

A

Communicators, receive information, via synapses, integrate the info and transmit electrical impulses

16
Q

Most neurones are _____ with many ____ and one ____

A

Most neurones multipolar with many dendrites and one axon

17
Q

What are glial cells?

A
  • Astrocytes - Oligodendrocytes - Microglia - Ependymal cells
18
Q

What are astrocytes

A

Star shaped cells Role in support, maintaining BBB, environmental homeostasis

19
Q

There is no ____ tissue in the CNS

A

There is no connective tissue in the CNS

20
Q

What are oligodendrocytes?

A

Produce myelin in the CNS - Nucleus becomes moderately stained in typical preparations

21
Q

What are microglia

A

Similar to macrophages (haematopeoic origin). Immune monitoring and antigen presentation

22
Q

Describe resting microglia

A

Elongated nuclei and a number of short, spiny cell processes

23
Q

Describe activated microglia

A

Round and take on similar appearance to macrophage

24
Q

What are ependymal cells

A

Ciliated cuboidal/columnar epithelium that lines the ventricles

25
Q

What is a fissure?

A

Deeper fold than a sulcus

26
Q

What is contained in white matter?

A

Axons (most myelinated) and their support cells

27
Q

What is contained in grey matter?

A

Huge number of neurones, cell processes, synapses and support cells

28
Q

Where is white matter located in the spinal cord?

A

Outside the H of grey matter

29
Q

How will you know what is the posterior spinal cord?

A

Posterior (dorsal horn) of grey matter is close to surface

30
Q

What is white matter referred to as in the spinal cord?

A

Columns -posterior -lateral -anterior

31
Q

What is the lateral fissure of the brain also called?

A

Sylvian fissure

32
Q

What is the inter hemispheric fissure called?

A

longitudinal fissure

33
Q

What are the two lentiform nuclei?

A

Putamen (superior) Globus Pallidus (inferior)

34
Q

What is the name of the structure labelled red?

A

Corpus callosum

35
Q

What is the name of the structure labelled red?

A

Thalamus

36
Q

What is the name of the structure labelled red?

A

Cingulate sulcus

37
Q

What is the name of this structure?

A

Interthalamic adhesion

38
Q

What are the two blanked out structures?

A

Fornix

Pineal Gland

39
Q

Describe the frontal lobe

A

large lobe anterior to the central sulcus and superior to the lateral sulcus

lobe anterior to a line drawn from the central sulcus down to the corpus callosum

40
Q

Describe the parietal lobe

A

posterior to the central sulcus, superior to the lateral sulcus (and a backward extension of it), and anterior to a line from the parieto-occipital sulcus to the preocciptialnotch

posterior to the frontal lobe and anterior to the parieto-occipital sulcus

41
Q

Describe the occipital lobe

A

posterior to a line from the parieto-occipital sulcus to the preocciptialnotch

42
Q

Describe the temporal lobe

A

inferior to the lateral sulcus (and a line extending the lateral sulcus posteriorly) and posteriorly by a line from the parieto-occipital sulcus and the preoccipitalnotch.

Medially, the temporal lobe extends from the temporal pole, to a line drawn between the preoccipitalnotch and the anterior end of the calcarine sulcus.

43
Q

Describe the insular lobe

A

Normally hidden

44
Q

What are the three layers of the meninges?

A

From superficial to deep;

  • Dura mater
  • Arachnoid Mater
  • Pia mater
45
Q

What is found in the subarachnoid space?

A

CSF

46
Q

What can the CSF filled ventricles inside the brain be compared to?

A

An alien antelope

47
Q

What are the two midline ventricles?

A

III and IV

48
Q

What is the enteric nervous system?

A
  • Found from oesophagus to rectum
  • neurons found in two plexuses in the walls of the gut (myenteric plexis between outer layers of smooth muscle, submucosal plexus in the submucosa)
49
Q

The enteric nervous system conrtains the same number of neurons found in the ______ ____ (10-)

A

The enteric nervous system conrtains the same number of neurons found in the spinal cord (108)

50
Q

What are the two systems suppling blood to the brain?

A

Internal carotid system

Vertebro-basilar system

51
Q

What arteries arise from the internal carotid arteries?

A
  • anterior cerebral
  • middle cerebral
52
Q

What arteries aries from the vertebral arteries?

A

Basilar artery

Posterior cerebeal arteries

53
Q

What is the blood supply here?

A
54
Q

What is the blood supply here?

A
55
Q

Describe the venous drainage of the brain?

A

Drains into a system of dural venous sinuses

56
Q

Where are the two enlargements of the spinal cord?

A

Cervical = upper limb

Lumbar= lower limb

57
Q

Anterior and posterior rootlets coalesce to form a posterior and anterior ___

A

Anterior and posterior rootlets coalesce to form a posterior and anterior root

58
Q

Roots pass through the ______ ____ until they reach the appropriate intervertebral _____

A

Roots pass through the subarachnoid space until they reach the appropriate intervertebral foraminae

59
Q

As the roots pass through the intervertebral foramina the ____ root is _____ by the ______ ____ _______

A

As the roots pass through the intervertebral foramina the dorsal root is enlarged by the dorsal root ganglion

60
Q

The roots fuse to form the ____ _____ nerve, which produces ___ and ____ rami

A

The roots fuse to form the mixed spinal nerve, which produces posterior and anterior rami

61
Q

Where does the spinal cord terminate?

A

Conus medullaris which in turn continues as a thin connective cord tissue called the filum terminale which is anchored to the dorsum of the coccyx

62
Q

What ligament suspends the spnal cord in the canal?

A

Denticulate ligament

63
Q

What forms the denticulate ligament?

A

Pial and arachnoid tissue

64
Q

What does the white matter of the sponal cord consist of?

A

Longitudinally orientated nerve fibres (axons), glial cells and blood vessels

65
Q

What does the grey matter of the spinal cord consist of?

A

Neuronal soma, cell processes, synapses, glia and blood vessels

66
Q

What opens rostrally into the IVth ventricle?

A

Central canal of the spinal cord

67
Q

What is significant about the grey matter at T1 to L2 spinal segments?

A

There is also a smaller lateral horn which contains the preganglionic sympathetic neurons

68
Q

What is the arterial supply to the spinal cord?

A

longitudinal arteries

> one anterior

  • > two posterior*
  • originate from vertebral arteries*

Segmental arteries

derived from intercostal and lumbar arteires

Radicular arteries

travel along the dorsal and ventral roots

69
Q

Describe the venous drainage of the spinal cord

A

Has both longitudinal and segmental veins

70
Q

What is contained within the epidural space?

A

Adipose tissue

Anterior and posterior epidural venous plexuses

71
Q

The left side of the somatosensory cortex represents the ____ side of the body

A

The left side of the somatosensory cortex represents the right side of the body

72
Q

How do sensory fibres for fine touch and conscious proprioception reach the somatosensory cortex?

A

Through the dorsal column/medial lemniscus system

  • fasciculus fracilis
  • fasciculus cuneatus
73
Q

Where do fibres going to somatosensory cortex cross?

A

In the medulla and synapse in the thalamus

74
Q

What does the spinothalamic tract carry?

A

Pain, temperature, deep pressure

75
Q

Where does the spinothamic neurones cross?

A

Segmentally and synapse in thalamus

76
Q

Describe the location of the spinothalamic tract in the spinal cord

A
77
Q

The left motor cortex controls the..

A

right side of the body

78
Q

The somatosensory cortex lies ____ to the central sulcus

A

Posterior

79
Q

What is the corticospinal tract responsible for?

A

Descending motor tract

-fine, precise movement, particularly of distal limb muscles

80
Q

The corticospinal tract forms visible _____ referred to as the ____ on the anterior surface of the ____ and so is sometimes called the _____ tract

A

The corticospinal tract forms visible ridges referred to as the pyramids on the anterior surface of the medulla and so is sometimes called the pyramidal tract

81
Q

_____ fibres form the lateral CST

_________ fibres form the ventral CST which then cross _____

A

crossed fibres form the lateral CST

uncrossed fibres form the ventral CST which then cross sementally

82
Q

What is decorticate posturing?

A

Spastic paralysis with hyperflexion of the upper limbs; caused by lack of descending control of the CST

83
Q

Where do 85% of CST fibres cross?

A

The lower medulla- deccusation of the pyramids

84
Q

What is the tectospinal tract?

A

Mediates reflex head and neck movement due to visual stimuli

85
Q

Where does the tectospinal tract cross?

A

Midbrain

86
Q

What is the reticulospinal tract?

A

Many functions, including the influencing of voluntary movement

reticular formation forms the central core of the brainstem, it has many nuclei and recieves input from virtually all parts of the CNS

87
Q

Where do reticulospinal tract fibres originate?

A

Areas of the reticular formation in pons and medulla

88
Q

What are RST fibres originating from the pons facilitators of?

A

Extensor movements and inhibitors of flexor movements

Fibres that originate in the medilla inhibit extensor movements and facilitate flexor movement

89
Q

What is the role of the vestibulospinal tract?

A

Excitatory input to antigravity extensor muscles

90
Q

Where do vestibulospinal tract fibres originate?

A

In the vestibular nuclei of pons and medulla (recieving input from vestibular apparatus and cerebellum)

91
Q

Describe brown-séquard’s syndrome

A

Associated with hemisection of the spinal cord.

Some sensory or motor problems

Asymmetrical

92
Q

What are these structures?

A
93
Q

How is the cerebellum attached to the brainstem?

A

3 stalks- termed peduncles

  • middle
  • superior
  • inferior
94
Q

What are the three layers of the cerebellar cortex?

A

Molecular layer (outer)

Purkinje cell layer (middle)

Granule cell layer (inner)

95
Q

Where do important afferents to the cerebellum arise from?

A

Spinal cord- from somatic proprioceptors and pressure receptors

Cerebral cortex (relayed via the pons)

Vestibular apparatus- via vestibular nuclei

96
Q

How to projections to the cerebellum enter?

A

Via cerebellar peduncles and project to mainly the granule cell layer

97
Q

What is the only output of the cerebellum?

A

via the axons of the purkinje cells

98
Q

where do the axons of purkinje cells synapse?

A

on neurons of the deep cerebellar nuclei

99
Q

What does the output of the cerebellum contribute to?

A

Coordinating the functions of the motor tracts of the brainstem and spinal cord

100
Q

Where do most efferent axons of the deep cerebellar nuclei synapse

A

Most cross the midline and synapse in the thalamus

101
Q

What is the role of the cerebellar hemispheres?

A

Influnce the ipsilateral side of the body

102
Q

What is the role of the midline of the cerebellum?

A

Postural control

103
Q

Describe the presentation of a unilateral hemispheric lesion of the cerebellum

A

Disturbance of the coordination in the limbs. can result in intention tremor and unstready gait in the absence of weakness or sensory loss

104
Q

Describe bilateral cerebellar dysfunction

A

Slowed, slurred speech (dysarthria), bilateral incoordination of the arms and a staggering, wide based gait (cerebellar ataxia)

105
Q

Describe the presentation of a midline cerebellar lesion

A

patient will tend to fall over when standing or sitting despite preserved limb coordination

106
Q

What are the three functions of the basal ganglia?

A
  1. to facilitate all purposeful movement
  2. inhibit unwanted movements
  3. role in posture and muscle tone
107
Q

What are the 5 basal ganglia

A

Caudate nucleus

Putamen

Globus pallidus

Subthalamic nucleus

Substantia nigra

108
Q

What makes up the lenticular nucleus?

A

Putamen and globus pallidus

109
Q

What makes up the striatum?

A

Caudate nucleus

Putamen

110
Q

What makes up the corpus striatum

A

Caudate nucleus, putamen and globus pallidus

111
Q

Describe the intenal capsule

A
112
Q

Where is the substantia nigra located?

A

In the midbrain

113
Q

What is the pathology in parkinsons disease?

A

Degeneration of the dopaminergic neurons of the substantia nigra

114
Q

What is the direct pathway of the basal ganglia?

A

Enhances outflow of the thalamus, enhancing the desired movement

115
Q

What is the indirect pathway of the basal ganglia?

A

Inhibits outflow of the thalamus

116
Q

Unilateral lesions of the basal ganglia (in contrast to cerebellar lesions) affect the _____________ side of the body

A

Unilateral lesions of the basal ganglia (in contrast to cerebellar lesions) affect the contralateral side of the body

117
Q

Lesions of the _____ _______ generally ____ cause paralysis, sensory loss, loss of power or ataxia

A

Lesions of the basal ganglia generally don’t cause paralysis, sensory loss, loss of power or ataxia

118
Q

Lesions of the basal ganglia cause what motor signs?

A

Changes in muscle tone

Dyskinesias (abnormal, involuntary movements)

  • tremor, chorea, myoclonus
119
Q

What are sinusoidal movements?

A

Tremors

120
Q

What is chorea?

A

Rapid, asymmetrical movements usually affecting distal limb musculature

121
Q

What is myoclonus?

A

Muscle jerks

122
Q

What diseases are represented by these abnormal changes in basal ganglia function?

A
123
Q

Cranial nerves exit _________ except IV which exits ___________ and VIII which exits _________.

A

Cranial nerves exit anteriorly except IV which exits posteriorly and VIII which exits laterally.

124
Q

What is the role of the olfactory nerve?

What is unique about its path?

A

Purely sensory cranial nerve

It is the only sensory modality that does not synapse in the thalamus prior to reaching the cortex

125
Q

Which cranial nerves are motor?

A

CN III, IV, VI, XI, XII

126
Q

What is the role of the occulomotor nerve?

A

Somatic motor to;

    • Levator palpabrae superioris*
  • SR, MR, IR, IO

Parasympathetic to;

  • sphincter pupillae
  • -ciliary muscle*
127
Q

Where is the occulomotor nerve’s nuclei of origin?

A

Midbrain

128
Q

What is the role of the trochlear nerve?

A

Somatic motor to superior oblique muscle

129
Q

Where is the trochlear nerves nuclei of origin?

A

Midbrain

130
Q

Where does the trochlear nerve exit?

A

Posteriorly

131
Q

What is the role of the abducens nerve?

A

Somatic motor to lateral rectus

132
Q

Where is the nucleus of origin for the abducens nerve?

A

Caudal pons

133
Q

What is the role of the hypoglossal nerve?

A

Somatic motor to;

  • genioglosus
  • hyoglossus
  • styloglossus
  • intrinsic tongue muscles
134
Q

Where is the nuclei of origin of the hypoglossal nerve?

A

Medulla

135
Q

Where does the spinal accessory nerve arise?

A

From the spinal cord

136
Q

What are the mixed cranial nerves?

A

CNs- V, VII, IX AND X

137
Q

What are the functions of the trigeminal nerve

A
  1. somatosensation of face: discriminative touch, vibraiton sense, pain, temperature
  2. proprioception associated with chewing (TMJ, muscles of mastication, teeth)
  3. motor control- muscles of mastication, tensor tympanii, mylohyoid, anterior belly of digastric, tensor veli palatini
138
Q

The sensory nucleus of the trigeminal forms a long _____ of neurons that stretches from the ________ down to the upper _ segments of the _______ _____ ____. It has _ parts, separated by function.

A

The sensory nucleus of the trigeminal forms a long column of neurons that stretches from the midbrain down to the upper 2 segments of the cervical spinal cord. It has 3 parts, separated by function.

139
Q

What is the function of the mesencephalic nucleus?

A

Proprioception info from chewing muscles

140
Q

What is the function of the pontine trigeminal nucleus (principal nucleus)?

A

Discriminative touch, vibration

141
Q

What is the function of the spinal nucleus?

A

Pain, temperature

142
Q

What is unusual about the mesencephalic nucleus?

A

The only site in the CNS where the cell bodies of primary afferent neurones live inside the CNS. It is a retained sensory ganglion.

143
Q

What offers an advantage regarding the location of the mesencephalic nucleus?

A

Its proximity to the motor nucleus- offers advantages in terms of jaw reflexes.

144
Q

Describe the ventral trigenimothalamic tract fibres

A

Most cross the midline, but some don’t (therefore bilateral representation of touch, vibration in cortex)

145
Q

What does the spinal trigeminal nucleus merge with?

A

Dorsal horn of upper cervical spinal cord

146
Q

What are the three functions of CN VII

A
  1. motor (muscles of facial expression, stapedius)
  2. parasympathetic innervation to pterygopalatine and submandibular ganglia
  3. Tasta (anterior 2/3 of tongue via c. tympani
147
Q

What are the 4 functions of CN IX?

A
  1. tactile sense, pain and temperature sense from the posterior tongye, pharyngotympanic tube and upper pharynx
  2. taste (posterior 1/3 of tongue)
  3. parasympathetic fibres to the otic ganglion (parotid gland)
  4. motor (one muscle : stylopharyngeus)
148
Q

What are the 4 functions of the vagus nerve?

A
  1. tactile sense, pain and temperature sense from the pharynx, larynx, trachea, oesophagus and thoracic and abdominal viscera
  2. taste (epiglottis)
  3. parasympathetic innervation to ganglia serving thoracic and abdominal viscera
  4. motor (striated muscle of pharynx and larynx) (cranial accessory contributes to this function)
149
Q

Describe the path of the facial nerve fibres

A

fibres from the motor nucleus loop around the abducens nucleus

150
Q

What nuclei do the components of the facial nerve originate from?

A
  • facial motor nucleus
  • salvitory nucleus
  • solitary nucleus
  • spinal trigeminal
151
Q

What nuclei does the glossopharyngeal originate from?

A
  1. Solitary n: Gustatory nucleus – taste, v Commissural nucleus- visceral information
  2. Spinal trigeminal nucleus (small region of somatosensation associated with the ear)
  3. Inf. Salivatory n. (parasymp)
  4. Nucleus ambiguus (stylopharyngeus muscle)
152
Q

What nuclei are involved with the 4 components of the vagus nerve?

A
  1. Dorsal (motor) Nucleus (parasymp)
  2. Solitary -taste
    Commissural – visceral information
  3. Spinal trigeminal nucleus (pain from dura and small region of somatosensation associated with the ear).
  4. Nucleus Ambiguus (motor)
153
Q

Which nerves is the solitary nucleus involved with and what does it do?

A

taste and visceral sensory information

CNs VII, IX, X,

154
Q

Which nerves use the superior and inferior salivatory nuclei and what is their function?

A

CNs VII and IX

Parasympathetic efferents to ganglia of salivary glands and pterygopalatine ganglion

155
Q

Which nerves use the nucleus ambiguus and what is its function?

A

CNs IX and X (and part of cranial nerve XI)

Motor efferents to muscles of pharynx, larynx and upper oesophagus

156
Q

Describe the shape of the solitary nucleus?

A

It extends in a V shape from upper to lower medulla

157
Q

What visceral sensations does the solitary nucleus account for?

A

Commisural nucleus (visceral afferents)

IX- carotid sinus/body

X aortic arch and viscera (pulmonary stretch receptors)

158
Q

The corticobulbar tract is the part of the pyramidal tract that is _____ to _____ nerves.

A

The corticobulbar tract is the part of the pyramidal tract that is motor to cranial nerves.

159
Q

The corticobulbar tract includes fibres to the motor nuclei of which CNs?

A

V, VII, X and XII

160
Q

Which part of the face has a bilateral supply from the corticobulbar tract?

A

Upper face (forehead and around the eyes)

161
Q

Where is the input containing parasympathetic efferents to CN III, VII, IX and X from?

A

From the hypothalamus- its efferents reach the preganglionic autonomic neurons both directly and via synapses in the reticular formation

162
Q

The reticular formation is a network of loosely aggregated cells with ____ ______, _____ and _____ intermingling in the central core of the _____ ____.

A

The reticular formation is a network of loosely aggregated cells with cell bodies, axons and dendrites intermingling in the central core of the brain stem.

163
Q

What do the reticular formation centres do?

A
  • integrate cranial nerve reflexes
  • particupate in conduction and modulation of pain
  • influence voluntary moement
  • regulate autonomic activity
  • integrate some basic functions, like respiration and sleep
  • activate the cerebral cortex
164
Q

A medial bilateral lesion of the brainstem retiuclar formation at or above the upper pons causes what?

A

Irreversible coma