Cranial Nerves Individually

Question 1

Olfactory

Answer 1

cell bodies originate from the olfactory organ in the roof of the nasal cavity

special sensory (special visceral afferent)

enters cranium through the cribriform plate

Question 2

Oculomotor

Answer 2

Parasympathetic that also carries somatic to eye

cell body originates

visceral motor

1) Presynaptic = midbrian
2) Postsynaptic = ciliary ganglion

Somatic motor
1) midbrain

enters cranium through the superior orbital fissure

Parasympathetic component associated ganglion: ciliary ganglion for lens accommodation, sphincter pupillae, ciliary muscles that constrict the pupil

Somatic component: motor to superior, inferior, and medial recti, inferior oblique, levator palpebrae muscles that raise superior eyelids and direct faze superiorly inferiorly, and medially

Question 3

Optic

Answer 3

cell body arises from retina cells (retina ganglia cells)

special sensory (somatic)

enters cranium through the optic canal

vision from retina

Question 4

Trochlear

Answer 4

somatic motor for eye

cell body arises from midbrain

motor to superior oblique, assists in directing gaze “inferolaterally”

Question 5

Trigeminal

Opthalmic division

Answer 5

somatic sensory

Consists of

a) Frontal nerve (main tract)
b) supra-orbital nerve (cutaneous nerve)
c) Nasalciliary
d) Lacrimal

Dermatome distribution map of Opathalmic division is the top part of the head, running along the dorsal surface of the nose

foramina is the superior orbital fissure

Question 6

Trigeminal

Maxillary division

Answer 6

Somatic sensory only

Includes

Zygomatic nerve
Infra-orbital nerve (lower eyelid, upper lip)
Superior alveolar nerve (teeth)

jugular rotundum

Question 7

Trigeminal

Mandibular division

Answer 7

Sensory and motor

Includes 
Inferior alveolar nerves (teeth)
Auriculotemporal nerve 
meningeal nerve (sensory to the meninges)
buccal nerve (cheek)
lingual nerve 
mental nerve (cutaneous) 

jugular ovale

Question 8

Name the cranial postsynaptic parasympathetic ganglion and the cranial nerves they correspond to, their function, and the branch of the trigeminal they ride to deliver sensory or motor information

Answer 8

Otic, pterygopalatin, ciliary and submandibular ganglions

Otic - glossopharyngeal (IX)
Ciliary - oculomotor (III)
Pterygopalatin and submandibular - facial (VII)

Otic ganglion provides innervation to the parotid gland (salivary gland)

Ciliary ganglion provides muscle for ciliary constriction, inferior obliques, superior, medial, and inferior rectus, and lens accommodation

Pterygopalatin supplies innervation to the lacrimal gland, the nasal cavity (mucous production) and oral cavity (saliva production)

Submandibular ganglion supplies innervation to the sublingual gland (the “glicking” muscle”) and the submandibular glands

Question 9

Facial Nerve

Answer 9

CN VII

Consists of four different modalities

a. Visceral motor (pterygopalatine: tear production, mucous production, saliva production)
b. branchial motor (special visceral efferent): supplies stapedius, stylohyoid, and posterior belly of digastric muscles, the muscles of facial expression, including buccinator, and occipitalis muscles
c. Special sensory (taste from anterior 2/3 of the tongue and hard/soft palates)
d. General sensory: skin behind ear

Question 10

SVE

Answer 10

Special visceral efferent (SVE) refers to efferent nerves that provide motor innervations to the muscles of branchial arches.[1]
Some sources prefer the term “branchiomotor”,[2] or “branchial efferent”.[3]
The only nerves containing SVE fibers are cranial nerves: the trigeminal nerve (V), the facial nerve (VII), the glossopharyngeal nerve (IX), the vagus nerve (X) and the accessory nerve (XI).[4]

Question 11

Which cranial nerve possesses special visceral efferent, general visceral efferent, general somatic afferent, and special afferent modalities?

Answer 11

the facial nerve

Question 12

Facial nerve: visceral motor

Answer 12

General visceral efferent

Main nerves carrying preganglionic parasympathetics:

Greater petrosal nerve 
Chorda tympani (taste)

pre-ganglion parasympathetics going to pterygopalatine (lacrimal, mucosa, saliva) and submandibular

Question 13

Facial nerve: Branchial motor

Answer 13

Special visceral efferent

all the muscles of facial expression, posterior belly of digastric

Question 14

Facial nerve: General sensory

Answer 14

skin of the ear, inner portion

stuff related to the ear but not much

Question 15

Facial nerve: Special sense

Answer 15

special afferent

taste 2/3 of tongue

Greater petrosal nerve 
Chorda tympani (taste)

Question 16

Facial nerve in a nutshell

Answer 16

Somatic branchial branch does facial muscle movement

Visceral motor branches use the chorda tympani and greater petrosal nerves to deliver postganglionic parasympathetic signals TO the pterygopalatine and TO the submandibular ganglions for their related functions (saliva, mucous, tears)

General sensory (afferent) skin behind ears, inner ears a bit (not much)

special sensory (tongue): uses chorda tympani and greater petrosal nerves to deliver signals

Question 17

Glossopharyngeal

Answer 17

IX, presympathetic paraganglion signal via tympanic neve to otic ganglion; from the otic ganglion via the auriculomotor nerve on V3 to the parotid gland

two associated nerves and pathways

Tympanic Nerve —> otic ganglion —> V3, auriolotemporal nerve —> parotid gland

Somatic motor: innervates one muscle, the stylopharynegus

Visceral motor: parotid gland (salivation)

Visceral sensory: carries sensation from the carotid body and the carotid gland

General sensory: 1/3 of the posterior tongue, outer ear, and internal surface of tympanic membrane

Special sense: 1/3 of the posterior tongue

associated with the jugular foramen

Question 18

Vagus sigh

Answer 18

X

Branchial motor (everything to do with speech with a few exceptions) (special visceral efferent): to striated muscles in the pharynx, larynx (except for the stylopharyngeus) and laveator muscle

Visceral motor (general visceral efferent) (ALSO EVERYTHING TO DO WITH SPEECH plus abdominal and thoracic extremities) smooth muscle and glands of the pharynx, larynx, thoracic and abdominal viscera

Visceral sensory (visceral afferent): 
FROM the larynx, trachea, esophagus, thoracic, abdominal viscera, stretch receptors in the aortic arch, chemoreceptors in the aortic bodies adjacent to the arch 

General sensory
From the skin at the back of the ear and in the external acoustic meatus, part of the external surface of the tympanic membrane, and the pharynx