week 3

Question 1

origin of the facial nerve

Answer 1

the pons. Begins as two roots (large motor and a small sensory)

Question 2

greater petrosal nerve function

Answer 2

parasympathetic innervation of the lacrimal and mucous glands (excluding the parotid)

Question 3

nerve to stapedius

Answer 3

stapedius muscle acts to stabilise the stapes, reducing the amplification of sounds

Question 4

chorda tympani

Answer 4

provides special sensory fibres to the anterior two-thirds of the tongue, and some parasympathetic fibres to the submandibular and sublingual glands

Question 5

where the facial nerve exits the cranium

Answer 5

stylomastoid foramen

Question 6

origins of the vestibulocochlear nerve

Answer 6

vestibular component - vestibular nuclei located in the pons and medulla
Cochlear component - ventral and dorsal cochlear nuclei located in the inferior cerebellar penduncle

Question 7

type of neurons in the vestibulocochlear nerve

Answer 7

bipolar - special sensory

Question 8

schwannoma

Answer 8

beign cerebellopontine angle tumour that grows from the superior component of the vestibulocochlear nerve. Slow-growing tumour of the schwann cells which surround both the facial and vestibulocochlear nerve . Tumour normally arises from the vestibular branch

Question 9

key defining symptom of a schwannoma

Answer 9

unilateral sensorineural hearing loss

Question 10

menieres disease

Answer 10

auditory disease characterised by an episodic sudden onset of vertigo, low-frequency hearing loss, low frequency roaring tinnitus, and a sensation of fullness in the affected ear. Cause unknown but thought to be due to overproduction or impaired absorption of endolymph in the ear.

Question 11

if there is an extra-cranial lesion to the facial nerve what type of functions will be damaged

Answer 11

motor

Question 12

Tarsorrhaphy

Answer 12

Tarsorrhaphy is a surgical procedure in which the eyelids are partially sewn together to narrow the eyelid opening. It is done to ensure the cornea does not dry out, as patients may have weakness in their orbicularis oris muscle, meaning they cannot close their eye.

Question 13

incomplete lesion

Answer 13

term used to describe partial damage to the spinal cord. Some motor and sensory function will remain. Depends on where the lesion has occurred in the spinal cord as to what functions remain (sensory and/or motor

Question 14

first reflexes to return after spinal shock

Answer 14

babinski and bulbocavernous

Question 15

Autonomic dysreflexia

Answer 15

• Spinal cord lesions above the T6 spinal cord level (generally)
• Acute AD is a reaction of the ANS to overstimulation
• Characterised by
o paroxysmal hypertension (the sudden onset of severe high blood pressure)
 throbbing headaches,
 profuse sweating,
 nasal stuffiness,
 flushing of the skin above the level of the lesion,
 slow heart rate, anxiety
• Believed to be triggered by afferent stimuli originating below the level of the spinal cord lesion
o Noxious stimuli
• Leads to sympathetic over-reaction
• Can be brought on by a blocked catheter

Question 16

frontal lobe

Answer 16

movement, decision-making, problem solving and planning. Three main divisions:
prefrontal cortex - personality expression and planning of complex behaviours.
premotor cortex - voluntary muscle movement
primary motor cortex

Question 17

parietal lobe

Answer 17

processing of tactile sensory information such as pressure, touch and pain. Location of the somatosensory cortex

Question 18

occipital lobe

Answer 18

main centre for visual processing - location of the primary visual cortex

Question 19

temporal lobe

Answer 19

structures of the limbic system are located here.
Lobes are involved in organising sensory input, auditory perception, language and speech production
Location of Wernicke’s and Broca’s areas, as well as the primary auditory cortex

Question 20

Broca’s area

Answer 20

motor aspects of speech - damage to this area will result in expressive aphasia, non-fluent and slow speech

Question 21

Wernicke’s area

Answer 21

sensory language understanding, and lexical processing. Damage to this are will result in receptive aphasia and extremely poor comprehension

Question 22

primary auditory cortex

Answer 22

processing of sound information

Question 23

corpus striatum

Answer 23

caudate nucleus, putamen and globus pallidus

Question 24

subthalamic nuclei

Answer 24

produces the excitatory neurotransmitter glutamate

Question 25

substantia nigra

Answer 25

production of dopamine, involved in the nigro-striatal pathway

Question 26

amygdala

Answer 26

located deep within the medial temporal lobes - primary role in the processing memory of emotional reactions

Question 27

hippocampus

Answer 27

formation, organisation and storage of memories

Question 28

Primary brain injury

Answer 28

occurs during the initial insult of a traumatic brain injury, resulting from the displacement of physical structures of the brain. Includes concussions

Question 29

concussion

Answer 29

brain injury associated with a loss of consciousness, typically for a few minutes. There are no persisting abnormal neurological signs, although long-term symptoms such as a headache, impaired concentration etc. may be reported.

Question 30

diffuse axonal injury

Answer 30

generally follows significant rotational acceleration and deceleration forces, causing widespread damage to axonal tracts. May be present without abnormal imaging findings but where there are MRI is best, and haemosiderin can be seen deposited at the junctions of deep grey and white matter, within white matter tracts, or in the basal ganglia.
Treatment is supportive. Injuries generally result in substantial cognitive impairment and personality change with/ or without physical neuro-disability.

Question 31

results of raised ICP

Answer 31

can cause focal neurological deficit, dependent on the location of the bleed and where the pressure is being applied.
If untreated then coning can occur:
one or both temporal lobes can herniate through the tentorium cerebelli. This compresses the midbrain and third cranial nerve
herniation of the cerebellar tonsils through the foramen magnum, compressing the medulla. Can cause neurological deterioration and death

Question 32

epidural haemorrhage

Answer 32

blood accumulation in the space between the dura and the calvarium. More common in young children than adults as their dura is less tightly attached to their skulls.
Usually occurs following a skull fracture in the temporal region - no primary brain injury usually.
Due to rupture of the middle meningeal artery (or a branch of this.) Results in an acute epidural haemorrhage, that if not stopped rapidly can lead to temporal lobe herniation and death.

Question 33

subdural haematoma

Answer 33

usually a result of tearing of the cerebral veins due to some sort of injury. Leads to pooling of blood in the potential space between the dura and arachnoid mater. Forms slower due to the venous supply and generally occurs after some form of primary brain injury.
Acute subdural haematoma is more common in the elderly as the brain is more mobile in the cranial cavity

Question 34

intracerebral haematoma/haemorrhage

Answer 34

can be single or multiple. More commonly occurs in the frontal or temporal lobes.
May occur in association with the severe motion that the brain undergoes during a head injury. Can occur as a result of a contusion coalescing into a haematoma.
temporal haematomas are more dangerous as the brain can herniate laterally (temporal lobe is liable to herniation)

Question 35

consciusness

Answer 35

a state of alertness and attentiveness to one’s environment and situation. A fully conscious individual is awake, alert, orientated in time, person, place and current circumstance

Question 36

cerebral perfusion pressure

Answer 36

the difference between mean arterial pressure and intracranial pressure. It represents he gradient that drives cerebral blood flow. Normally auto-regulated by the brain by altering the resistance of cerebral blood vessels.

Question 37

burst-lobe

Answer 37

intracranial haemorrhage affecting a brain lobe which is mixed with necrotic brain tissue which has ruptured into the subdural brain space

Question 38

Key genes for eye development

Answer 38

PAX6 - master gene for eye development (activatory), restricted to optic cup and lens by PAX-2 which is present in the optic stalk and which is upregulated by SHH
SHH - orbit seperation

Question 39

factors inhibiting neuronal regrowth in the CNS (recovery of function)

Answer 39

Neurons degenerate at a very slow rate (months to years)
Only grow small re-growths, then astrocyte hypertrophies, formation of a glial scar
Increased ECM molecule production by astrocytes and oligodendrocytes
Myelin (jettisoned by oligodendrocytes) and oligodendrocytes both contain anti-growth molecules

Question 40

neural plasticity

Answer 40

the ability of the CNS to change it connectivity and can occur in various contexts including learning, memory, damage and learning