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Lab Unit 4 Exam > Cranial Nerve and Functions > Flashcards

Flashcards in Cranial Nerve and Functions Deck (29):

Cranial Nerve 1

Description: Conducts olfactory (smell), sensations to brain; only type of nervous tissue to regenerate.

Sensory Function: Olfaction (smell)


Pathways of CN 1 Olfactory

Travels through Cribriform foramina of the ethmoid bone and synapses in the olfactory bulbs, which are located in the anterior cranial fossa.

Origin: Receptors (bipolar neurons) in olfactory mucosa of the nasal cavity.


What is Cranial Nerve II

Optic Nerve


Function of CN II?

Description: Special Sensory Nerve of Vision that is an outgrowth of the brain; known as the brain tract
Sensory Function: Vision


Pathway and Origin of CN II Optic Nerve?

Origin: Retina of the eye

Pathway: enters the cranium via optic canal of the Sphenoid bone; left and right optic nerves unite at optic chiasm. Optic tract travels to lateral geniculate nucleus of thalamus.


What is CN III?

Oculomotor Nerve


Function of Oculomotor Nerve, CN III?

Description: Innervates upper Eyelid muscle abd four of the six extrinsic eye muscles

Somatic Motor Function: Supplies four Extrinsic eye muscles( superior rectus, Inferior rectus, medial rectus, inferior oblique) that move the eyesupplies levator palperbrae superiorismuscle to elevate eyelid

Parasympathetic Motor Function: Innervates sphincter pupillae of iris to make pupil constrict. Contracts cilliary muscles to make lens of eye more spherical


Origin and pathway of Oculomotor Nerve CN III

Origin: Oculomotor and Edinger Westphal nuclei within the mesencephalon

Pathway: Leaves Cranium via superior orbital fissure and travels to eye and eyelid


Name CN IV?

Trochlear Nerve


What is the Somatic Function Of CN IV?

Description: Innervated one extrinsic eye muscle that loops through a pulley shaped ligament

Somatic Function: Supplies one extrinsic muscle (superior Oblique) to move eye inferiorly and laterally


What is the Origin and Pathway oF CN IV?

Origin: Trochelar nucleus within the mesencephalon

Pathway: leaves cranium via superior orbital fissure and travels superior oblique


What is the cranial Nerve V?

Trigeminal Nerve


What is the descriptionof the CN V ?

Description: This nerve cavity consists of three divisions opthalmic, maxillary and mandibular receives sensory impulses from face, oral cavity, nasal cavity and anterior scalp and innervates muscles masstication


What are the functions of the Trigerminal Nerve (CN V)?

Motor Function: Innervated muscles of Mastication ( mylohyoid, pterygoids, masseter, temporalis, anterior belly of digastric) tensor tympani. Cell bodies in the nuclei in pons

Sensory Function: Sesnory Stimuli for this nerve are touch, temperature and pain. Bodies in ganglion (trigeminal ganglion), Face _(skin, jaws, tongue,, sinuses, teeth), Opthalmic (V1); Maxillary (v2) and Mandibular (V3)


What is CN VI

Abducens Nerve


What is the Function of Abducens Nerve (VI)?

Description: Innervates Lateral Rectus eye muscle. which abducts the eye( pulls away laterally)

Somatic Motor Function: Innervates one extrinsic eye muscle ( lateral rectus) for eye of abduction. Nuclei Pons


Origin CN VI Abducens Nerve?

Nucleus in pons

Pathway: Leaves Cranium through superior orbital fissure and travels to lateral rectus muscle


What is CN VII?

Facial Nerve


Function of CN VII Facial Nerve?

Sensory Function: Taste from anterior 2/3 of tongue. Celll bodies in ganglion

Somatic Motor Function (Efferent): The five major motor branches ( temporal, zygomatic, buccal, mandibular, and cervical) (To Zanzibar By Motor Car). Cell bodies in the nucleus in pons . Stylohyoid muscles of facial expression, posterior belly of digastric, buucinator, stapedius.

Parasympathetic : efferent perganglionic, Increases secretions of the lacrimal gland of the eye as well as the submandibuar and sublinguinal salivary gland


What is CN VIII

Vestibulocochlear Nerve


What is the Function of CN VIII Vestibulocochlear Nerve?

Sensory Function: Afferent sensory only, Innervates spiral Organ of Corti ( Cocholear branch) (Hearing), Innervates saccule and utricle and semicircular ducts (Veistibular branch) , (balance and movement).



Glossopharyngeal Nerve


What is the Function of Glossopharyngeal Nerve (CN IX)?

Afferent Sensory: Receptors in taste buds and posterior 1/3 of tongue and mucosa. Cell bodies in ganglion

Efferent Motor: Bodies in nucleus in medulla oblongata, terminates stylopharyngeus (Pharynx muscle)

Efferent Preganglionic Paray sympathetic: increases secretion of parotid salivary gland


What is Cranial Nerve X?

Vagus Nerve


What are the functions of Vagus Nerve (CN X)

Parasympathetic Efferent: Preganglionic, Innervates the visceral smooth muscle, Cardiac muscle and glands of heart, lungs Pharynx, larynx, trachea and most abdominal.

Motor Efferent: Cell bodies in nucleus in medulla oblongata. Terminates on muscles of Larynx and Pharynx.

Sensory Afferent: Bodies in ganglion, Receptors in mucosa of larynx, alimentary canal to left of colic flexure, lungs and bronchii.


What is Cranial Nerve XI?

Accessory Nerve


Function of Accessory Nerve (CN XI)

Efferent Motor Only. Bodies in the nucleus in medulla oblongata, Terminates on sternocleidomastoid and Trapezius.

Crainial Root: Travels with CN X fibers to pharynx


What is Cranial Nerve XII?

Hypoglossal Nerve


What is the Function Hypoglossal Nerve (CN XII)

Somatic Motor: Efferent, bodies in nucleus of medulla oblongata, Terminates on muscles of tongue, genioglossus, hyopglossus and styloglossus ( innervates intrinsic and extrinsic tongue muscles)

name means under the tongue.