Summary of Cranial nerves

Summary of Cranial nerves

Pure Sensory cranial nerve:  olfactory nerve, optic nerve and vestibulocochlear nerve (1, 2, 8)

Function of sensory nerve in short:

1. Olfactory nerve : carry smell
2. Optic nerve : responsible for vision
3. Vestibulocochlear nerve : vestibular part responsible for balance and cochlear nerve responsible for vision

No.	Sensory nerve	Component	Name of the opening through which nerve enter  into the cranium	Arises from
I	Olfactory nerve	SVA	Cribriform plate of ethmoid	Axon of olfactory nerve arises from the Olfactory  cells which are situated in the nasal mucosa
II	Optic nerve	SSA	Optic canal	Optic nerve fibres are arises from  the ganglionic cells of the retina
VIII	Vestibulocochlear  nerve	SSA	Internal acoustic meatus	Nerves are arises from inner ear (hair cells)

 

Pure motor cranial nerve:  Oculomotor,  trochlear and abducent , accessory nerve and hypoglossal nerve (3, 4, 6,   11, 12)

 

Oculomotor, trochlear and abducent nerves are pure motor nerve which innervate extraocular muscles

	Nerves	Functions	Nucleus	Name of the opening through which nerve exit the cranium
III	Oculomotor nerve	All extra-ocular muscles of  eye are supplied by oculomotor nerve except SO and LR	Oculomotor nucleus Edinger –Westphal  nucleus	Superior orbital fissure
IV	Trochlear nerve	SO 4: superior oblique muscle is supplied by trochlear nerve	Trochlear nucleus	Superior orbital fissure
VI	Abducent nerve	LR 6: lateral rectus muscle is supplied by abducent nerve	Abducent nucleus	Superior orbital fissure

 

XI	Accessory nerve	Functions	Nucleus	Name of the opening  through which nerve exit  the cranium
	Cranial root	It supplies all muscles of soft palate ( except tensor veli  palatine) and all muscles of  the pharynx except stylopharyngeus	Spinal accessory nucleus	Jugular foramen
	Spinal root	This part supplies the sternocleidomastiod and trapezius muscles		Foramen magnum
XII	Hypoglossal nerve	It supplies all muscles of the tongue except  palatoglossus	Hypoglossal nucleus	Hypoglossal canal

Mixed cranial nerves: (V, VII, IX, X)

·         Trigeminal nerve,

·         Facial,

·         Glossopharyngeal,

·         Vagus 

Trigeminal nerve (V)

It has three parts

		Foramen	Function	Nucleus of trigeminal nerve
Ophthalmic nerve	sensory nerve	Superior orbital fissure	Carry sensation from Upper part of face	Motor nucleus of trigeminal nerve Spinal nucleus of trigeminal nerve Main sensory nucleus of trigeminal nerve and  mesencephalic nucleus of trigeminal nerve
Maxillary nerve	sensory nerve	Foramen Rotundum	Carry sensation from Middle part of face
mandibular nerve	Mixed : both sensory and motor	Foramen ovale	Sensory : Lower part of face & general sensation from the ant 2/3 of tongue Motor : muscles of mastication, tensor tympani, tensor veli palatine

 

Facial nerve (VII) Functions (in short):

Sensory function: carry taste sensation from ant 2/3 of tongue

Motor function: motor innervation of muscles of facial expression

Secretomotor function: innervate lacrimal gland through pterygopalatine ganglion 

Glossopharyngeal nerve functions(IX) (in short):

Sensory function: carry taste sensation and general sensation from pos 1/3 of tongue 

Motor function: innervate stylopharyngeus muscle

Secretomotor function: innervations of parotid gland through otic ganglion

Vagus nerve(x) function in short :

Sensory function: carry taste sensation from post most part of tongue, carry sensation from larynx, external ear

Motor innervations: muscles of larynx