Cranial nerves 1: Introduction, Eye movements and Autonomics

Question 1

what is the function of the olfactory nerve (1)

Answer 1

sense of smell

special visceral afferent

Question 2

what is the function of the optic nerve (2)

Answer 2

sense of sight

special somatic afferent

Question 3

what is the function of the occulomotor nerve (3)

Answer 3

eye movements

somatic efferent
p’symp visceral efferent in addition

Question 4

what is the function of the trochlear nerve (4)

Answer 4

Eye movements

somatic efferent

Question 5

what is the function of the trigeminal nerve

Answer 5

sensation- head and cavities

motor- muscles of mastication

also a carrier

Question 6

what is the function of abducent nerve (6)

Answer 6

eye movements

Question 7

what is the function of the facial nerve (7)

Answer 7

motor - muscles of facial expression

also taste (nervus intermedius)

Question 8

what is the function of vestibulocochlear nerve (8)

Answer 8

hearing and balance

Question 9

what is the function of glossopharyngeal (9)

Answer 9

sensation of posterior third of tongue and oropharynx

Question 10

what is the function of the vagus nerve (10)

Answer 10

p’sympathetic visceral - heart, lungs, GI tract

Question 11

what is the function of spinal accessory nerve

Answer 11

motor to sternocleidomastoid and trapezius

Question 12

what is the function of hypoglossal (12)

Answer 12

motor to tongue

Question 13

why might abduccens be stretched in raised intracranial pressure

Answer 13

passes upwards on the clivus

Question 14

why might oculomotor be compressed in raised intracranial pressure

Answer 14

it lies superior and adjacent to the tentorium cerebelli

Question 15

what nerves might be compromised in a circle of willis aneurysm

Answer 15

oculomotor (3)

passes between the posterior
cerebral and superior cerebellar branches of the circle of
Willis, before lying close to the posterior communicating
artery.

Question 16

special visceral efferent

Answer 16

descending information to branchial muscles (mastication, pharynx and larynx)

Question 17

special somatic afferent

Answer 17

sight, hearing, balance

Question 18

general somatic afferent

Answer 18

sensory from the body

Question 19

special visceral afferent

Answer 19

taste and smell

Question 20

general visceral afferent

Answer 20

ascending information from heart, lungs, gut, etc

Question 21

general visceral efferent

Answer 21

descending information to heart, lungs, gut

Question 22

somatic efferent

Answer 22

descending motor to body

Question 23

what nuclei are found in the midbrain (4)

Answer 23

mesencephalic trigeminal nucleus
edinger westphall (3)
occulomotor
trochlear

Question 24

what nuclei are found in the pons (6)

Answer 24

chief sensory nucleus (5)
motor trigeminal (5)

facial (7)
abducens (6)

superior salivatory (7)
inferior salivatory (9)

Question 25

what nuclei are found in the medulla

Answer 25

spinal trigeminal nucleus (5,7,9,10) solitarius(8,9,10) dorsal motor vagal nucleus (10) ambiguous (9, 10) spinal accessory (11) hypoglossal (12)

Question 26

what is the function of the spinal trigeminal nucleus

Answer 26

crude touch, temp and pain from ipsilateral face receives input from 5,7,9,10

Question 27

solitary nucleus

Answer 27

a series of purely sensory nuclei (clusters of nerve cell bodies) forming a vertical column of grey matter embedded in the medulla oblongata contributes to autonomic regulation cn 8, 9, 10 (7 is part of tract)

Question 28

what are the inputs to the solitary nucleus

Answer 28

taste from ant tongue via facial sensory from ear (auricular branch of vagus) Chemoreceptors and mechanoreceptors in the carotid body via glossopharyngeal nerve, and aortic bodies via the vagus nerve

Question 29

dorsal motor vagal nucleus (medulla, general visceral efferent)

Answer 29

parasympathetic vagal functions in the gastrointestinal tract, lungs, and other thoracic and abdominal vagal innervations.

Question 30

nucleus ambiguous (9,10)

Answer 30

innervate the muscles of the soft palate, pharynx, and larynx which are strongly associated with speech and swallowing also psymp to heart

Question 31

what is the basal plate

Answer 31

found in the anterior part of the developing spinal cord, becomes the motor part of the spinal cord found medially in the brainstem opposite of alar plate

Question 32

what is the sulcans limitans

Answer 32

hole in the developing spinal cord which later becomes the central canal

Question 33

intermediate nerve

Answer 33

found between the motor component of the facial nerve and the vestibulocochlear nerve sensory and psymp fibres of the facial nerve

Question 34

what structures does the abducent nerve travel through

Answer 34

cavernous sinus superior orbital fissure tendinous ring

Question 35

what structures does the trochear nerve pass through (arises dorsally)

Answer 35

cavernous sinus | superior orbital fissure

Question 36

what structures does the occculomotor nerve pass through

Answer 36

cavernous sinus superior orbital fissure tendinous ring

Question 37

what nerve can be damaged in raised intracranial pressure due to its proximity to the tentorium cerebelli

Answer 37

oculomotor

Question 38

what nerve can be damaged in raised intracranial pressure due to it passing upwards on the clivus

Answer 38

abducent

Question 39

why do the nerves for eye movement pick up sympathetic fibres

Answer 39

they pass close to the sympathetic fibres which form a plexus on the internal carotid artery

Question 40

where is the superior orbital fissure

Answer 40

between the lesser and greater wings of the spenoid (lateral wall of orbit)

Question 41

what wall of the orbit does the sphenoid bone make

Answer 41

lateral

Question 42

what modalities does the occulomotor nerve contain

Answer 42

somatic motor psymp from edinger westphal sympathetics from the carotid plexus

Question 43

what way does the eye turn in an occulomotor nerve injury (due to sup oblique and lateral rectus)

Answer 43

downwards and laterally | upper eyelid droops

Question 44

sympathetic part of occulomotor

Answer 44

``` pupil dilation (nasocilliary) smooth muscle part of levator palpebrae superioris ```

Question 45

parasympathetic part of occulomotor

Answer 45

synapses in the ciliary ganglion (from E-W nucleus) pupil constriction lens accommodation via cilliary muscle

Question 46

what controls the lacrimal gland

Answer 46

psymp system facial nerve