Cranial nerves

Question 1

Describe the olfactory nerve in terms of its:
- function
- fibre type
- cranial exit
- cranial entry/entry into brainstem

Answer 1

Olfactory nerve or CNI is a sensory nerve. Its fibres are solely sensory fibres.
The olfactory nerve enters rostral to the brainstem, and it lies just under the frontal lobe (i.e. it emerges from the telencephalon).
Exit from the brainstem is the cribiform plate of the ethmoid bone

Olfactory nerves, due to their embryological origin, are not part of the CNS*

Question 2

Describe the optic nerve in terms of its function, fibres, entry and exit from cranium

Answer 2

Optic nerve CNII has special sensory function, like Olfactory nerve. Its fibres are also solely sensory. The chief function of the optic nerve is sight.
The nerve enters rostral to the brainstem, and connects to the occipital lobe via thalamus (i.e. in the diencephalon), and exits the cranium via the optic canal, within the sphenoid bone

Note: optic nerve may be considered not a true cranial nerve because it is an extension of the brain, and is thus a component of the CNS, rather thant the PNS.

note: 1, 2, 8 = pure sensory fibres

Question 3

What is true of the cranial nerve nuclei?

Answer 3

A single nucleus is assigned for each function

Question 4

Are cranial nerves with autonomic function sympathetic or parasympathetic?

Answer 4

ALWAYS parasympathetic

Question 5

List the cranial nerves in order and describe the logic behind their numbering

Answer 5

• CN I, Olfactory nerve (not shown in the image)
• CNII, Optic nerve
• CNIII, the Oculomotor nerve
• CNIV, the Trochlear nerve
• CNV, the Trigeminal nerve
• CN VI, the Abducens nerve
• CN VII, Facial nerve
• CN VIII, Vestibulocochlear nerve
• CN IX, Glossopharyngeal nerve
• CN X, Vagus nerve
• CN XI, Accessory nerve
• CN XII, Hypoglossal nerve

The twelve pairs of cranial nerves are designated numbers from 1 - 12, written in Roman numerals. These correspond to the order of their emergence from the brainstem.

Question 6

Describe the origins of the olfactory and optic nerves

Answer 6

The olfactory and optic nerves emerge from the telencephalon ^[in other words, the cerebral hemispheres] and diencephalon ^[region consisting of structures surrounding the third ventricle that is located on the midline] respectively.

Question 7

Describe the origin of the oculomotor and trochlear nerves

Answer 7

The oculomotor and trochlear nerves emerge from the mesencephalon ^[a.k.a the midbrain, the shortest part of the brain. It connects the pons and cerebellum with the forebrain].

think 2 (4 above), 4, 4,

Question 8

Describe th origin of trigenminal abducent and facial nerves

Answer 8

The trigeminal, abducent, and facial nerves emerge from the pons.

Question 9

Describe th eorigin of the other cranial nerves

Answer 9

The remaining nerves emerge from the medulla oblongata.

n.b. spinal accessory nerve

double origin but always comes out of the jugular foramen. The jugular foramen develops embryologically from the otic capsule and the baseplate. Its spinal portion comes from a series of roots starting at C6-C7 and traveling cranially to enter in the foramen magnum.

Question 10

Which nerves emerge from ponto=-medullary junciton?

Answer 10

Three other cranial nerves are located at the pontomedullary junction: the abducens nerve (cranial nerve VI), the facial nerve(cranial nerve VII), and the vestibulocochlear nerve (cranial nerve VIII).

Question 11

Why might the optic nerve not be considered a true cranial nerve?

Answer 11

it is an extension of the brain, and is thus a component of the CNS and not a peripheral nerve.

Question 12

True or false: olfactory nerves are part of CNS

Answer 12

The olfactory nerve is the shortest cranial nerve, and along with the optic nerve is one of the only two cranial nerves that do not converge with the brainstem. Embryologically, the olfactory nerve is a derivative of the forebrain and is therefore considered a component of the central nervous system

pulled from statpearls

Question 13

List the pure sensory nerves

Answer 13

Some nerves are pure sensory: I, II, VIII (olfactory, optic, vestibulocochlear)

Question 14

List the pure motor nerves

Answer 14

III, IV, VI, (XI) ^, XII (oculomotor, trochlear, abducens, accessory, hypoglossal).

[XI comes through the foramen magnum and goes into the cranial space, bypassing the brainstem. It does not have an individual or selective function]

Question 15

List the mixed cranial nerves

Answer 15

V, VII, IX and X (trigeminal, facial, glossopharyngeal, and vagus nerve)

Question 16

TRUE or FALSE: cranial nerves with autonomic function are sometimes sympathetic

Answer 16

FALSE: If the cranial nerve has autonomic function it is always parasympathetic

Question 17

List the cranial nerves that emerge from the midbrain

Answer 17

• midbrain: III and IV
  
  • pons: V, VI, VII, VIII
  • medulla: IX, X, XI, XII

Question 18

Where does cranial nerve two synapse?

Answer 18

CN II synapses in the thalamus, and is really the output of the thalamus- does not have a connection to the brainstem

Question 19

Where does cranial nerve one synapse?

Answer 19

CNI does not connect to the brainstem, doesnt need a brain to perform chemoreception - and is the only one that does not connect with the thalamus

Question 20

Describe the function of the trigeminal nerve and its branches

Answer 20

The trigeminal nerve is the main sensory nerve ^[2] of the face, and has three branches. (it is a somatic sensory nerve
It is huge, and thus a big structure such as the trigeminal nucleus cannot be set on one level, therefore, it builds upwards and spans across the length of the entire brainstem. It has different parts depending on where they are located in the brainstem.
- Ophthalmic branch or V1 - sensations from the nasal cavity, skin of forehead, upper eyelid, eyebrow and nose
- Maxillary branch or V2 - sensations from lower eyelid, upper lips and gums, teeth of the maxilla, cheek, nose, palate, and pharynx
- Mandibular branch or V3 - sensations from teeth of the mandible, lower gums and lips, palate and tongue

Note that sensation from the cornea is also picked up from the somatic sensory nerve. The corneal reflex- touching cornea and closing eyes - is lost in ophthalmic nerve damage.

2- THE trigeminal nerve is mainly a sensory nerve, although it does have branchial motor function in V3: to innervate muscles of mastication, as well as mylohyoid adn anterior digastric muscles. It is considered a mixed nerve, altho not atrue mixed, because it has no autonomic function

Question 21

What would be the consequence of damage to trigeminal ganglion?

Answer 21

Damage to the trigeminal ganglion will lead to loss of sensation in the face.
Sites of injury can include:
- entry to the skull: superior orbital fissure (V1), foramen rotundum (V2) and foramen ovale (V3 - f. ovale is site of entry and exit)
- entry and exit from the brainstem i.e. the pons
- termination of the primary sensory neuron: sensory trigeminal nucleus

Question 22

Describe the role of the facial nerve, in terms of its somatic motor role

Answer 22

Facial nerve or CNVII is a mixed nerve. It has branchial and visceral motor branches, and somatic and special sensory branches.
The facial nerve has five main branches, splits from the parotid gnd into: temporal, zygomatic, buccal, mandiibular and cervical.

Question 23

Describe the muscles of facial expression, their attachements, and list some examples

Answer 23

Muscles of facial expression are attached to the bone on one side and another to the skin
This is different and special to normal muscles - allows the movement of the eyelid, mouth and nose.
- frontalis
- orbicularis oculi - circular, around the eye responsible for closing the eye
- levator labii superioris - elevating the upper lib
- zygomaticus
- buccinator - innervated by CN VII (drooling, big buccinator)
- risorius - smiling muscle
- procerus
- corrugator supercilli
- nasalis
- orbicularis oris - surrounds the lips and close your mouth
- depressor anguli oris - depressing angle of the mouth
- platysma - covers the neck
- depressor labii inferioris

Question 24

Describe the oculomotor nerve in terms of its function, fibres, entry and exit from cranium

Answer 24

The oculomotor nerve or CNIII is a motor nerve. It has both somatic and visceral motor function. The somatic motor fibres are responsible for the movement of the eye muscles ^[1] (exc LRand SO) and for proprioception more generatlly.

The visceral motor fibres are parasympathetic fibres, travel to ciliary ganglion, control ciliary muscle and sphincter pupillae

Cranial exit is via superior orbital fissure (sphenoid : greater wing) and entrance to brainstem is at anterior junction of midbrain and pons

1- five nuceli, for four extrinsics and levatir palpebrae superioris

Question 25

Describe the trochlear nerve in terms of its function, fibres, entry and exit from cranium

Answer 25

The trochlear nerve is a somatic motor nerve, it si reponsible for moving the superior pblique muscles.
Itexists from superior orbital fissure and enters brainstem via posterior aspect of midbrain i.e. it travels around midbrain.

Question 26

TRUE or FALse cranial nerves innervate structures on the ipsilateral side

Answer 26

TRUE in general, the cranial nerves innervate structures on the ipsilateral side

Question 27

Describe the location of cranial nerve in the brainstem

Answer 27

why is this clinically relevant?
The above diagram is relevant e.g. if blood supply is lost to either medial or lateral end of brainstem…is somatic or motor function affected?

Note the branchial (Special) visceral motor nerves. Despite the fact that they innervate somatic structures i.e. the muscles of mastication (in the case of motor V), facial muscles (motor VII), and nucleus ambiguus, they are involved with structures or organs innervated by autonomic nerves.

Question 28

What is a difference between somatic and branchial nerves?

Answer 28

Osmosis:
the difference between somatic and branchial motor is that branchial motor fibers are just fibers that innervate structures derived from the pharyngeal arches, which are also sometimes called the branchial arches.

Question 29

Examples of function of CNV

Answer 29

hewing, control of food going through pharynx/oesophagus to gastrointestinal tract

Question 30

Examples of function of CN VII

Answer 30

keeps oral cavity open, keeps food inside, and controls food going through pharynx/oesophagus to gastrointestinal tract

Question 31

Examples of function of IX and X

Answer 31

protect and guide, GIT*

Question 32

Describe the nerve necessary for olfaction

Answer 32

Cranial nerve I (CNI) or the olfactory nerve is responsible for olfaction
- It passes through the cribriform plate, olfactory bulb ^[located in anterior cranial fossa] and olfactory tract and ends by dividing into medial and lateral ‘striae’ once it reaches the anterior perforated substance (at level of optic chiasm)
- the medial stria is responsible for autonomic responses to smell ^[such as? increase in salivation, gastric peristalsis or secretion; see https://www.ncbi.nlm.nih.gov/books/NBK556051/]
- the lateral stria is responsible for emotional link to smell. Why? Because it passes through temporal lobe, near amygdala and hippocampus* which are associated with emotions and memory. In other words, it is associated with the limbic system

The olfactory nerve originates from the olfactory placode, a common origin of both it, and the glial cells that supports the nerve.
It is a special visceral afferent nerve aka sensory, autonomic (recall [[Anatomy Lecture 6]], special and general sensations).

Clinically, examining the olfactory nerve is part of a complete cranial nerve examination.
Test each nostril to identify a certain smell (with eyes closed)

Anosmia or the absence of the sense of smell.
Number of mechanisms of anosmia: temporary, permanent, a result of neurodegenerative conditions i.e. progressive, or congenital.

Question 33

Describe nerve associated with vision

Answer 33

Cranial nerve II (CNII) or the optic nerve is responsible for vision.
![[Untitled.jpg]]

The primary visual cortex is composed of several components:
- cones/rods
- bipolar neurons
- ganglion cells - axons from the optic nerve
- optic nerve to the optic chiasm
- LGN (lateral geniculate nucleus) of the thalamus
- optic radiations
- primary visual areas of the occipital lobes
![[Pasted image 20230510110023.png]]

NOTE: the nerves that move the eyes (III, IV, VI - oculomotor, trochlear, abducens) ARE NOT responsible (directly?) for vision.

Question 34

Describe the pupillary response or pupillary reflex

Answer 34

The pupillary response or pupil reflex constricts the pupil in response to light ^[https://www.ncbi.nlm.nih.gov/books/NBK537180/].

The afferent segment of the pupillary response/or the nerve? starts in the retina and travels to the pretectal olivary nuclei. It decussates in the nasal retina but not in the temporal retina.

The interneuron segment of the pupillary response runs from the pretectal olivary nuclei to the Edinger-Westphal nuclei, preganglionic parasympathetic nuclei in the midbrain.

The efferent segment runs from the Edinger- Westphal nuclei to the pupillary constrictor muscle to constrict the pupil, via the ciliary ganglion, which sends postganglionic axons to directly innervate the iris sphincter muscles ^[https://www.ncbi.nlm.nih.gov/books/NBK537180/].
The direct response is constriction of pupil in the ipsilateral eye; the consensual response is constriction of pupil in the contralateral eye.
![[Pasted image 20230510112136.png]]
![[Pasted image 20230510112152.png]]

It is tested by shining a light into one pupil and looking for a response in the other pupil (which constricts as well).
The swinging lamp sign: move light to the contralateral pupil; the ipsilateral pupil will then dilate after light has moved away from it (this is called an afferent pupillary defect) ^[https://www.derangedphysiology.com/files/cranial%20nerve%20exam.pdf]
The pupillary reflex exam is considered part of a neurological exam.

Question 35

Describe the nerves involved in facial sensation

Answer 35

Cranial nerve V (CN V) or the trigeminal nerve is responsible for sensations in the face. It is therefore a sensory nerve. Recall that there are three branches of the trigeminal nerve:
- V1 or the ophthalmic nerve, enters the skull from the orbit via the superior orbital fissure
- V2 or the maxillary nerve, enters through the foramen rotundum, after collecting sensory fibres to reach the pterygopalatine fossa
- V3 or the mandibular nerve, enters and exits vi foramen ovale, passing from infratemporal fossa ^[note: motor fibres leave the pons to reach the infratemporal fossa through foramen ovale]. V3 controls the muscles of mastication (see [[Anatomy Lecture 8]])

A mnemonic to remember the branches of the trigeminal nerve is:
The (Trigeminal) Option Maximises Mangoes

Question 36

Describe the nerves involved in facial movement

Answer 36

Cranial nerve VII (CN VII) or facial nerve is responsible for the movement of the face i.e. it is the main mover of the face. It is thus largely a motor nerve (with some sensory function)= mixed.
Exits from the brainstem, specifically the pons, laterally in the pontomedullary-cerebellar angle.

Exits and enters skull via:
- internal acoustic meatus
- stylomastoid foramen
- petrosotympanic fissure
- hiatus of the facial canal -
- pterygoid canal

![[Pasted image 20230510114210.png]]
Recall:
Branches of facial nerve:
- temporal
- zygomatic
- buccal
- marginal mandibular
- cervical

Question 37

Describe the nerves involved in hearing and balance

Answer 37

The vestibulocochlear nerve or cranial nerve VIII (CN VIII) is responsible for both hearing and balance.
It is a special somatic afferent (or sensory) nerve that consists of two roots, anatomically and functionally:
- vestibular root, transmits impulses from the vestibular apparatus. Gives rise to the vestibular nerve
- cochlear root, transmits impulses from the auditory apparatus. Give rise to cochlear nerve
![[Pasted image 20230510114606.png]]
Auditory information is sensed by auditory hair cells, transmit this information to spiral ganglion, to cochlear nerve, to cochlear nucleus (in medulla), and then inferior colliculus (caudal midbrain), medial geniculate nucleus (in thalamus) and to gyri of Heschl (in the auditory cortex).

![[Pasted image 20230510114641.png]]

Balance information? is sent from macular hair cells or cupula, to vestibular ganglion, along vestibular nerve, to the four vestibular nuclei (in lateral corner of rhomboid fossa in pons/medulla oblongata ).

Question 38

Describe the roles of glossopharyngeal and vagus nerves

Answer 38

The glossopharyngeal and vagus nerves contain both sensory and motor fibres.
On the sensory side:
- IX carries taste fibres from the posterior third of the tongue, and visceral sensory fibres from the carotid body to the solitary nucleus
- It also carries tactile fibres from the posterior third of the tongue, upper pharynx and middle ear and transmits this information to the trigeminal nucleus
- X carries visceral sensory information from viscera in the body and aortic baroreceptors to the solitary nucleus, and some tactile fibres (from where?) to the trigeminal nucleus

On the motor side:
- IX and X include motor fibres that innervated striated muscles (i.e. of the pharynx, larynx, soft palate, see also [[Anatomy Lecture 12]]). It does somatic motor innervation.

^involuntary, despite being morphologically skeletal?, emanating from the nucleus ambiguus

NOTE: parasympathetic fibres are included in both IX and X:
- IX fibres synapse in the otic ganglion and innervate the parotid gland (inferior salivatory nucleus - in upper medulla)
- X fibres innervate the heart, bronchi and GIT and synapse in the walls of the viscera (dorsal vagal nucleus, in medulla)

Note 2: both dorsal nucleus of X/dorsal vagal nucleus, and nucleus ambiguus are motor nuclei.

Side note: ambiguus relates to the mixed nature of the nuclei, as it has the cell bodies of both IX and X

Question 39

What is the role of the accessory nerve?

Answer 39

The accessory nerve or cranial nerve XI is responsible for the shrugging of shoulders. It is thus (primarily) a motor nerve.
Head, neck and shoulder movement is actioned by the trapezius and sternocleidomastoid muscles, and thus XI innervates these.
Accessory nerve also mediates swallowing (via pharyngeal muscles) together with IX and X (via pharyngeal plexus).

Accessory nerve enters skull via foramen magnum and exits via jugular foramen.
Accessory nerve exits from brainstem via medulla, lateral to olive.

Related nuclei include spinal accessory nerve (from C1-5) and nucleus ambiguous. Note that there is a dispute as to whether CNXI is a real cranial nerve, as its nuclei are primarily found in C1-5, as it is relatively superiorly positioned, it “sticks” to the spinal cord and enters via the foramen magnum, where it hitchhikes with CNIX (glossopharyngeal) and CNX (vagal) nerves. ^[ this is clinically important, as damage to cranium and subsequent damage to the pharyngeal plexus]

Damage to the accessory nerve impairs head, neck and shoulder movement.

NOTE: clinicians are typically referring to the spinal root of the accessory nerve. It is this part that supplies the trapezius and sternocleidomastoid muscles, general somatic efferent.
(cranial root, special visceral efferent, innervate laryngeal muscles, merged with X. Generally considered part of X) <- Thieme

Question 40

Describe the nerve involved in tongue movement

Answer 40

Cranial nerve XII or the hypoglossal nerve is responsible for the movement of the tongue. It is thus a (Somatic) motor nerve.
It innervates all intrinsic and extrinsic tongue muscles (excluding the palatoglossus muscle, which is innervated by the vagus nerve) to action tongue movements required for speech, food manipulation, and swallowing.

It exits from the brainstem from the medulla, lateral to pyramids, and exits from skull via hypoglossal canal (in occipital bone).

NOTE:
If both are damage, can’t protrude tongue
If one side is damaged - tongue deviates when it protrudes. The tongue deviates towards the affected side.
![[Pasted image 20230510123331.png]]

Question 41

True or false: trigeminal nucleus is limited to pons

Answer 41

Flase: extneds entire length of brainstem

Question 42

True or false: facial nerve innervates parotid gland

Answer 42

FALSE it only passes through

Question 43

Describe trigeminal nerve in terms of nerve type, function, entry and exit from brainstem

Answer 43

Trigeminal nerve or cranial nerve 5 is a mixed cranial nerve (although not true because no autonomic function, largely sensory).
Three branches: opthalmic maxillary and mandibular

V1 – General Sensory: skin, mucous membranes of front of head and nose, and conjunctiva
V2 – General Sensory: upper jaw
V3 – Brachial Motor: Muscles of mastication + mylohyoid/ant digastric
V3 – General Sensory: mandible

V1 Sup. Orbital fissure
V2 Foramen rotundum
V3 Foramen ovale

Large nerve off
anterior pons. Motor
division is more
anterior and smaller.

Question 44

Describe the abducent nerve in terms of nerve fibre type, function, entry and exit from brainstem

Answer 44

Abducent or cranial nerve VI, is a pure motor nerve.
Somatic Motor: Eye movement (LR6SO4); lateral rectus
cranial exit: Superior orbital fissure
entry into brainstem: Anterior brainstem
between pons and
medulla (most medial)

Question 45

Describe facial nerve in terms of nerve firbre type, function, exit from cranium and entry into brainstem

Answer 45

Facial nerve or CNVII is a mixed nerve.
Branchial Motor: Muscles of fascial expression + stylohyoid/ post digastric
Visceral Motor: parasympathetic fibres to pterygopalatine ggl via greater petrosal nerve
(lacrimal gland) and submandibular ggl (submandibular and sublingual glands)
Somatic Sensory: skin surrounding external acoustic meatus
Special Sensory: anterior two thirds of tongue and soft palate (via lingual nerve)

Enters internal acoustic
meatus
Exits stylomastoid foramen

Lateral brainstem
between pons and
medulla (more lateral
than CN6)

Question 46

Describe the vestibulocochlear nerve in terms of nerve fibre type, function, exit from cranium and entry into brainstem

Answer 46

CNVIII is a sensory nerve
Travels through internal
acoustic meatus
(temporal bone) before
splitting into trochlear
and cochlear nerves

Special Sensory: Hearing (cochlear) and balance (vestibular)

Internal acoustic meatus

Pons (lateral and caudal aspect)

Question 47

Describe glossopharyngeal nerve in terms of nerve fibre type, function, exit from cranium and entry into brainstem

Answer 47

Glossopharyngeal
‘gag reflex’ – innervates
posterior 1/3 of tongue
Baroreceptor (carotid
sinus)
Chemoreceptor – blood
gases

It is a mixed nerve

Branchial Motor: stylopharyngeus muscle
Visceral Motor: parotid gland (via otic ggl)
Visceral Sensory: baroreceptor and chemoreceptors in carotid sinus; mucosa of oropharynx and
isthmus (palatine tonsil, soft palate, post third of tongue) (Moore’s says it is general sensory)
Special Sensory: Posterior third of tongue

exit from jugular foramen
entry medulla

Question 48

Describe vagus in terms of nerve fibretype, function, exit from cranium and entry into brainstem

Answer 48

CN10 or vagus nerve
Mixed nerve

Somatic Sensory: inferior pharynx, larynx and root of tongue
Special Sensory: taste at root of tongue/ epiglottis (similar distribution to somatic sensory)
Visceral Sensory: thoracic and abdominal organs up to the splenic flexure
Somatic Motor: soft palate, pharynx, intrinsic laryngeal muscles (phonation), palatoglossus +
proprioception
Visceral Motor: thoracic and abdominal visceral
Sensory: viscera in thorax and abdomen until splenic flexure, inferior pharynx and larynx

Exit from jugualr foramen
Entry from medulla

Question 49

Descrube accessory nerve in terms of nerve fibre type, functions, exit from cranium and entry into medulla

Answer 49

CNXI or accessory nerve
Nerve arises from rootlets
of the spinal cord (cervical
segments)

Motor
Somatic Motor: sternocleidomastoid and trapezius

Enter through foramen
magnum and exit through
jugular foramina

Off brainstem.
Caudal. May branch
off CNX

note: —not true cranil

Question 50

Describe hypoglossal nerve in terms of nerve fibretype, function, exit from cranium and entry into braiinstem

Answer 50

Motor
Somatic Motor: Extrinsic and intrinsic tongue muscles (except palatoglossus)
Hypoglossal canal
Ventral aspect of
medulla

Question 51

Describe chorda tympani

Answer 51

Chorda tympani goes through the tympanic membrane exiting the skull at the petrotypanic fissure

branch of facial

lingual comes out of trig ganglion
lingual/travels or merges with to innervate anterior 2.3s

efferent secretomotor ro submand and sublingual cia submand ganglion

Question 52

Describe the upper and lower motor neurons of cranial nerves

Answer 52

Upper motor neuron (bulbar tracts) and lower motor neuron (motor aspect of cranial nerve). Remember that the fibres desiccate therefore if an upper motor neuron legion the upper part of the face will be normal because it has
input from both sides of the cortex. If a LMN lesion, the complete side of the face will be droopy.

Question 53

Describe nucleus ambiguus

Answer 53

The nucleus ambiguus: The nucleus ambiguus lies in the medulla. It forms an elongated collumn lying deep in the reticular formation, both in the open and closed parts of the medulla. Inferiorly, it is continuous with the spinal accessory nucleus. The nucleus ambiguus is a composite nucleus and contributes fibres to the glossopharyngeal, vagus and accessory nerves.

SVE or Branchial efferent

Question 54

List the autonomic ganglia

Answer 54

• ciliary (CNIII): E-W axons synapse here and then innervate sphincter pupillae and muscles and ciliary body. Smllest of fanflia. NOTE: sensory and symp fibres pass through here asw well, without synapsing. Just lat to opthalmic art
• pterygopalatine (CNVII): lacrimal nuceli - CNVII – tears lacrimal gland, sasal mucosa glands. Mainy greater petrosal brnach of facial (nervus intermedius)– to go to lacrimal and nasal mucosa (controls flow of blood, especiallt venous plexus of conchae/heating and cooling). also glands of hard plate
  some sensory from max nerve v2
• submandibular: superior salivary nuclei- CNVII – n, submax and submand, saliva
  nervus intermedius–>chora tympani
  sensory:lingual off V3
• otic: inf sal nucleus CN IX– parotid and minor salivary glands to produce saliva(mucosiu membrne on mouth)
• reaches parotid gland )lesser = tympanic nerve branch plus glosso– tympanic plexus)
• symo and sense (V3 auriculotemporal) also pass through

CPSO

Question 55

List sesnory ganglia of crnail nerves

Answer 55

Trigeminal ganglion: all sensory fibres foind to larger part of head
largest of cranial nerve ganglia

Geniculate ie knee shaped
CNVII
- taste: ant 2/3s
- fibres that collect sensory info from soft palat, outer ear, nasal cavity

Spiral:
- cnviii SENSORY
- cochlear branch
- cochkea: 1st order nerurons of acoustic path
- receive stimuli from organ of corti– axons form cohclear branch

Vestibular or scarpa’s”
- vestibular
- in fundus of int acoustic meatus

Supe and inf of vagus:
- superioir or jugualr: af information– post cranil fossa, aear
- inferor or nodose: transmit from mucosa of larynx pharynx and soft palate

Gloosphar: superior (middle ear, tympanic membrane)
inferior: mucosa 1/3 tongue, auditory tube, adjavent pharyngeal wall