Cranial Nerves

The cranial nerves that carry a sensory component are ____________

1. Trigeminal ganglion (CN V), also called the semilunar or gasserian ganglion 2. Geniculate ganglion (CN VII)

Pharyngeal arches are separated EXTERNALLY by _________.

4 pharyngeal clefts

What separates the pharyngeal arches INTERNALLY?

4 pharyngeal pouches

Another name for CN VI

Abducens nerve

Another name for CN XI

Accessory nerve

Location of synapse of ALL cranial sympathetics

All have synapsed in the superior cervical ganglion

Another term for pharyngeal arches

Branchial arches

If the cervical sinus does not disappear what is the result?

Branchial cysts and sinuses. They are remnants of the pharyngeal clefts and/or the cervical sinus Located along the anterior border of the sternocleidomastoid muscles. Branchial sinuses open into either the inside of the pharynx or onto the outside surface of the neck.

What type of nerves are categorized as special visceral efferent?

Branchial motor

The route of branchial motor branches of CN VII

Branchial motor branches exit via the stylomastoid foramen

What are branchial motor neurons responsible for innervating?

Branchial motor neurons supply muscles that develop in association with the pharyngeal arches.

Describe the route of CN III.

CN III enters the orbit by passing through the cavernous sinus and then the superior orbital fissure.

What supplies the 3rd arch?

CN IX (glossopharyngeal)

What supplies the 1st arch?

CN V (trigeminal)

Which cranial nerves carry branchial motor components?

CN V (trigeminal) to 1st arch muscles CN VII (facial) to 2nd arch muscles CN IX (glossopharyngeal) to 3rd arch muscles CN X (vagus) to 4th and 6th arch muscles

What supplies the 2nd arch?

CN VII (facial)

Describe route of the facial nerve

CN VII It exits the brainstem as two roots: The larger motor root and the intermediate nerve

What supplies the 4th arch?

CN X (vagus)

What supplies the 6th arch?

CN X (vagus)

Cranial sensory ganglia description

Cell bodies of sensory nerve fibers No synapses occur Similar to the dorsal root ganglia

Name the cranial nerve that supplies the third arch.

Cranial Nerve IX

What nerve supplies the second arch?

Cranial Nerve VII (also known as the facial nerve)

The muscles of the larynx, pharynx, and palate are supplied by which nerve?

Cranial nerve X (the vagus nerve)

What cranial nerve supplies the tongue and how?

Cranial nerves V, VII, IX, and X. These are sensory nerves only.

Which components may cranial nerves carry? A. somatic motor B. somatic sensory C. visceral motor D. visceral sensory E. special sensory F. branchial motor

Cranial nerves may carry any of the first four (A-D) as well as E and F. A. somatic motor B. somatic sensory C. visceral motor D. visceral sensory E. special sensory F. branchial motor

What does each pharyngeal arch have associated with it?

Each has its own associated cartilage, artery, nerve and muscle group.

Somatic (general) sensory component of CN X

Ear canal, meninges of the posterior cranial fossa

When do pharyngeal arches appear?

Early in embryonic development

Route of CN XII

Exits the skull via the hypoglossal canal. AND C1 fibers 'hitchhike' along it to join the ansa cervicalis.

T/F Branchial motor components are carried by spinal nerves.

F Branchial motor components are carried by CRANIAL nerves.

T/F All cranial nerves are motor and sensory.

F. Some are motor. Some are sensory. Some are mixed.

Another term for CN VII.

Facial nerve

Pierre Robin Syndrome is also known as __________.

First arch syndrome

Describe branchial fistulas.

Fistulas are a continuous open channel connecting two structures. Branchial fistulas extend from a pharyngeal pouch to the surface of the neck (very rare). 2nd arch fistula, connects the tonsillar fossa to the surface of the neck. 4th arch fistula may connect the piriform recess of the pharynx and thyroid gland to the surface of the neck.

How many pharyngeal arches are visible externally?

Four (1,2,3,4). Arch 6 is deep and not seen on the surface.

Another name for CN IX

Glossopharyngeal nerve

Another term for CN XII

Hypoglossal nerve

Where does the visual pathway end?

In the occipital lobe of the brain.

What is CN V3?

It is the mandibular nerve, the largest division of the trigeminal nerve (V).

Describe the route of CN V2.

It passes through the cavernous sinus and foramen rotundum. Then it enters the pterygopalatine fossa.

Describe the route of CN IV.

It passes through the cavernous sinus and the superior orbital fissure to enter the orbit.

How does CN II enter the cranial cavity?

It passes through the optic canal of the sphenoid bone to enter the cranial cavity.

What muscle(s) does cranial nerve IV supply?

It supplies one extraoccular muscle: the superior oblique muscle.

Visceral sensory component of CN X

Larynx, carotid sinus and body, thoracic and abdominal viscera

Another name for the first arch

Mandibular arch

Another term for CN V3

Mandibular nerve

What muscles does cranial nerve V3 supply?

Masseter, temporalis and pterygoids, anterior belly of the digastric, mylohyoid, tensor tympani and tensor veli palatini muscles. These are the muscles of mastication that develop in association with the first arch.

Another name for CN V2.

Maxillary nerve.

What may cause tic douloureux?

May be caused by pressure at the root of the nerve from adjacent blood vessels.

The tongue is innervated by what?

Motor nerves from cranial nerve XII innervate the tongue.

The route of CN VIII nerve fibers

Nerve fibers enter the cranial cavity through the internal auditory meatus.

Where does CN I enter the cranium?

Nerve fibers enter the cranial cavity via the cribriform plate of the ethmoid bone.

What is another name for CN III?

Oculomotor nerve

Another name for cranial nerve I.

Olfactory nerve

Where are olfactory nerve cells found?

Olfactory nerve cells are found in the nasal mucosa located at the roof of the nasal cavity

Which pharyngeal cleft is the only one to become an adult structure? What does it become?

Only the 1st becomes an adult structure. It becomes the external ear canal.

Another name for CN V1.

Ophthalmic nerve

The route of parasympathetic cell bodies of CN VII

Parasympathetic cell bodies: preganglionic fibers originate in the superior salivatory nucleus and synapse on postganglionic neurons in either the pterygopalatine ganglion or the submandibular ganglion

Describe the visceral motor component of CN VII.

Parasympathetic to the lacrimal, submandibular, and sublingual glands, mucous glands of the nose, pharynx, and palate

Visceral motor component of CN X

Parasympathetic to thoracic and abdominal viscera

What does the tongue mucosa develop from?

Parts of arches 1-4

Cranial parasympathetic autonomic ganglia description

Postganglionic cell bodies of parasympathetic nerves located here. Synapses occur here.

For cranial sympathetics, the route of their postganglionic fibers

Postganglionic fibers travel with these arteries to reach their target structures: Internal carotid (nerve) plexus External carotid plexus

Where do preganglionic fibers of CN III originate?

Preganglionic fibers originate in the Edinger-Westphal nucleus.

Route of visceral motor component of CN X

Preganglionic fibers originate in the dorsal motor nucleus of X and synapse in ganglia in or near their target organs.

Route of the visceral motor component of CN IX

Preganglionic fibers originate in the inferior salivatory nucleus, synapse in the otic ganglion

Describe the route of the visceral motor component of CN VII.

Preganglionic fibers originate in the superior salivatory nucleus, synapse in the pterygopalatine or submandibular ganglia

Synapse of preganglionic parasympathetic nerve which originate in brainstem nuclei

Preganglionic parasympathetic nerves (which originate in brainstem nuclei) synapse on the postganglionic neurons in these autonomic ganglia (cranial nerves III, VII, IX and X carry parasympathetics)

Describe the visceral sensory component of CN VII.

Small, unimportant contribution from the palate

What function does CN V3 carrout?

Somatic (general) sensory and branchial motor

Nervous system function(s) carried out by CN XI

Somatic motor

What nervous system function(s) does cranial nerve IV carry out?

Somatic motor

Do cranial nerves carry a parasympathetic component?

Some do, but not all.

Pharyngeal arches are composed of tissue that will become what?

Some of the bones, cartilage, ligaments and muscles of the head and neck.

What nervous system function(s) does CN VIII carry out?

Special sensory

What type of nerve is CN I?

Special sensory (smell). It is the olfactory nerve.

Nervous system function(s) carried out by CN X

Special sensory, branchial motor, visceral motor, visceral sensory, somatic (general) sensory

What nervous system function(s) does CN IX carry out?

Special sensory, branchial motor, visceral motor, visceral sensory, somatic (general) sensory

Which components may spinal nerves carry? A. somatic motor B. somatic sensory C. visceral motor D. visceral sensory E. special sensory F. branchial motor

Spinal nerves may carry A. somatic motor B. somatic sensory C. visceral motor D. visceral sensory They do not carry special sensory or branchial motor components.

Describe symptoms of "tic douloureux."

Sudden excruciating pain radiating along the pathways of a branch or division of the trigeminal nerve

Special sensory nerve components are responsible for what?

Taste, smell, sight, hearing, balance

In embryonic development, how does the 1st pharyngeal cleft become an ear canal?

The 1st cleft meets the 1st pouch at the tympanic membrane.

What do the 2nd, 3rd, and 4th clefts become?

The 2nd, 3rd, 4th clefts are overgrown and become the cervical sinus. Normally this sinus disappears.

The R and L nerves of CN II meet where? What do they become?

The R and L nerves of CN II meet at the optic chasm, becoming the optic tracts.

What nervous system function(s) does CN VI carry out?

The abducens nerve carries out only somatic motor functions.

Describe the route of CN VI.

The abducens nerve passes through the cavernous sinus and superior orbital fissure to enter the orbit.

What muscle does CN VI supply?

The abducens nerve supplies only the lateral rectus muscle (an extraoccular muscle).

What nervous system function(s) does CN VII carry out?

The facial nerve carries out special sensory, branchial motor, visceral motor, visceral sensory, and somatic (general) sensory.

Describe the branchial motor aspect of CN VII.

The facial nerve innervates muscles from the 2nd arch, the muscles of facial expression, which are the posterior digastric, stylohyoid, and stapedius muscles.

Describe the special sensory aspect of CN VII.

The facial nerve is responsible for taste from the anterior 2/3 of the tongue and from some palatine taste buds.

Name the 3 branches of the CN V1 / opthalmic nerve.

The frontal, lacrimal, and nasociliary branches (enter the orbit)

Describe the route of CN V3

The mandibular nerve passes through the foramen ovale to enter the infratemporal fossa.

The CN V3 supplies what?

The mandibular nerve supplies SOMATIC GENERAL SENSORY to the lower face, temporal region, mandibular dentition, tongue, and meningeal branches AND BRANCHIAL MOTOR to muscles associated w/ the 1st arch: muscles of mastication, anterior digastric, mylohyoid, tensor tympani, tensor veli palatini.

The CN V2 supplies what?

The maxillary nerve supplies somatic (general) sensory to the midface, nasal cavity, maxillary dentition, palate, meningeal branches.

Where do fibers of CN III synapse?

The nerve fibers of CN III synapse in the ciliary ganglion.

After passing through the cribriform plate of the ethmoid bone, where do CN I enter?

The olfactory bulb. Then the nerves become the olfactory tract leading to the temporal lobe of the brain.

What nervous system function(s) does CN V1 carry out?

The opthalmic nerve carries out somatic sensory functions.

Describe the route of CN V1.

The opthalmic nerve passes through the cavernous sinus and superior orbital fissure and splits into 3 branches that enter the orbit.

What does CN V1 supply.

The opthalmic nerve supplies somatic (general) sensory to the upper face, scalp, eye, nose, and meningeal branches.

Another name for cranial nerve II.

The optic nerve.

Name 5 things the second arch gives rise to.

The second arch (hyoid arch) gives rise to the stapes, styloid process, stylohyoid ligament, upper half of hyoid body and lesser horns.

The second arch gives rise to __________.

The second arch (hyoid arch) gives rise to the stapes, styloid process, stylohyoid ligament, upper half of hyoid body and lesser horns.

The somatic motor component of cranial nerves III supply ________.

The somatic motor component of cranial nerves III supply the extraoccular muscles.

Route of the spinal root of the accessory nerve

The spinal root originates from the cervical spinal cord, enters the cranial cavity through the foramen magnum, and then leaves through the jugular foramen.

The three divisions of the CN V (trigeminal) nerve are ___________, ___________, and ___________.

The three divisions of the CN V (trigeminal) nerve are V 1, ophthalmic V 2, maxillary V 3, mandibular

What nervous system function(s) does CN V carry out?

The trigeminal nerve is primarily somatic sensory. Only the mandibular division carries branchial motor.

The visceral motor component of cranial nerves III supply ________.

The visceral motor (parasympathetic) component of cranial nerves III supply smooth muscle associated with the eyeball.

There are ____ pairs of cranial nerves designated by ________.

There are 12 pairs of cranial nerves designated by Roman numerals I-XII.

How many branchial arches are there?

There are 5. They are numbered 1, 2, 3, 4, and 6.

Where are the sensory cell bodies of CN V found?

They are found in the trigeminal ganglion. The three divisions branch from the trigeminal ganglion.

What do these muscles have in common? Masseter, temporalis and pterygoids, anterior belly of the digastric, mylohyoid, tensor tympani and tensor veli palatini muscles

They are muscles of mastication, and they develop in assocation with the first arch

Describe the route of the parasympathetic and taste nerve fibers.

They hitchhike along the branches of the trigeminal nerve.

Another name for CN V.

Trigeminal nerve

What is the main somatic sensory nerve to the head?

Trigeminal nerve

Another name for CN IV.

Trochlear nerve.

First arch syndrome is associated with what symptoms?

Underdeveloped mandible Cleft palate Posterior displacement of the tongue

Another name for CN X

Vagus nerve

Another term for CN VIII

Vestibulocochlear nerve

The mandibular arch (arch 1) forms ___________.

a maxillary and mandibular prominence

How does tic douloureux first present in many cases?

as pain from the teeth

The 1st pharyngeal pouch develops into _______.

auditory (Eustacian) tube and tympanic cavity

What do the 4th and 6th arches develop into?

cartilages of the larynx

Names of the parasympathetic autonomic ganglia

ciliary ganglion (CN III) pterygopalatine ganglion (CN VII) submandibular ganglion (CN VII) otic ganglion (CN IX)

Roots of accessory nerve (CN XI)

cranial and spinal. The cranial root becomes part of the vagus nerve (we will consider it to be vagus).

Describe the somatic (general) sensory component of CN VII.

ear canal

Somatic (general) sensory component of CN IX

ear canal

Another way of saying "motor innervation"

efferent innervation In the nervous system, efferent nerves, otherwise known as motor or effector neurons, carry nerve impulses away from the central nervous system to effectors such as muscles or glands.

The location of ALL sensory cell bodies of CN VII

geniculate ganglion

Special sensory aspect of CN VIII

hearing and balance

Location of nerve cells of CN VIII

in the inner ear

Where are the nerve cells of CN II located?

in the retina

Where do CN I nerves end up in the brain?

in the temporal lobe

Location of ganglia associated with the vagus nerve

in the thorax and abdomen (near or in the viscera being supplied)

What may trigger tic douloureux?

light touch

The muscles of _________ develop in association with the first arch.

mastication

Branchial motor component of CN X

muscles associates with the 4th and 6th arches - the muscles of the pharynx, larynx, and palate

The _______________________ are derived from occipital somites.

muscles of the tongue

Pharyngeal arches form many structures of the ___________ and ______________.

neck and head

Each pharyngeal arch is supplied by how many cranial nerves?

one

The 2nd pharnygeal pouch develops into ________.

palatine tonsil and fossa

Visceral motor component of CN IX

parasympathetic to the parotid gland

What does the intermediate nerve carry?

parasympathetic, visceral sensory and taste fibers

Visceral sensory component of CN IX

pharynx, middle ear, carotid sinus/body

What are the muscles of facial expression innervated by CN VII?

posterior digastric, stylohyoid, and stapedius muscles

What other muscles develop in association with the second arch?

posterior digastric, stylohyoid, stapedius

The muscles of facial expression develop in association with the ________ arch.

second

2 types of cranial ganglia

sensory ganglia and parasympathetic autonomic ganglia

What nervous system function(s) does CN V2 carry out?

somatic (general) sensory

Nervous system functions carried out by CN XII

somatic motor

What nervous system function(s) do cranial nerves III carry out?

somatic motor and visceral motor

What type of nerve is CN II?

special sensory (sight)

The 4th pharyngeal pouch develops into ________.

superior parathyroids and the ultimobranchial body (parafollicular cells of the thyroid)

Somatic motor component of CN XII

supplies the muscles of the tongue

Special sensory component of CN X

taste from the base of the tongue

Special sensory component of CN IX

taste, posterior 1/3 of tongue

Cranial sensory ganglia are associated with _____________

the cranial nerves that carry a sensory component

Many of the muscles of the larynx, pharynx, and palate develop in association with __________.

the fourth and sixth arches

Another name for cranial nerve IX

the glossopharyngeal nerve

Another name for the second arch

the hyoid arch

What do the larger motor root and intermediate nerve pass through?

the internal auditory meatus

What does the third arch give rise to?

the lower part of the hyoid body, the greater horns of the hyoid bone, and the Stylopharyngeus muscle

What gives rise to parts of the zygomatic and temporal bones?

the mandibular arch (arch 1)

What gives rise to the incus?

the mandibular arch (arch 1)

What gives rise to the malleus?

the mandibular arch (arch 1)

What gives rise to the mandible?

the mandibular arch (arch 1)

What gives rise to the maxilla?

the mandibular arch (arch 1)

What gives rise to the sphenomandibular ligament?

the mandibular arch (arch 1)

The mandibular arch (arch 1) gives rise to _____________.

the maxilla, mandible, parts of the zygomatic and temporal bones, malleus and incus, and the sphenomandibular ligament

What does the vestibular branch of CN VIII conduct?

the special sense of balance

What does the cochlear branch of CN VIII carry?

the special sense of hearing

The cranial root of the accessory nerve (XI) becomes part of _____________________.

the vagus nerve

Route of the glossopharyngeal nerve

through the jugular foramen

Route of the vagus nerve

through the jugular foramen

The 3rd pharyngeal pouch develops into ________.

thymus and inferior parathyroids

Somatic motor component of CN XI

to the sternocleidomastoid and trapezius muscles

Branchial motor component of CN IX

to the stylopharyngeus muscle associated with the 3rd arch