cranial nerve anatomy and fxn

Question 1

List all the cranial nerves

Answer 1

1.olfactory
2.optic
3.occulomotor
4.trochlear
5.trigeminal
6.abducens
7.facial
8.vestibulocochlear
9.glossopharyngeal
10.vagus
11.accessory
12.hypoglossal

Question 2

How many pairs of cranial nerves are there?

Answer 2

12 pairs

Question 3

What is Cranial Nerve I and its function?

Answer 3

Cranial Nerve I is the Olfactory nerve. It carries afferent impulses for the sense of smell.

Question 4

What is the main function of Cranial Nerve II?

Answer 4

Cranial Nerve II, the Optic nerve, carries afferent impulses for vision.

Question 5

Which cranial nerves are located at the midbrain?

Answer 5

CN III (Oculomotor) and CN IV (Trochlear).

Question 6

Name the cranial nerves located at the pons.

Answer 6

CN V (Trigeminal), CN VI (Abducens), CN VII (Facial), CN VIII (Vestibulocochlear).

Question 7

Which cranial nerves are located at the medulla oblongata?

Answer 7

CN IX (Glossopharyngeal), CN X (Vagus), CN XI (Spinal Accessory), CN XII (Hypoglossal).

Question 8

List the sensory cranial nerves.

Answer 8

Sensory cranial nerves are CN I (Olfactory), CN II (Optic), CN VIII (Vestibulocochlear).

Question 9

Which cranial nerves are classified as motor nerves?

Answer 9

Motor cranial nerves are CN III (Oculomotor), CN IV (Trochlear), CN VI (Abducent), CN XI (Accessory), CN XII (Hypoglossal).

Question 10

Name the mixed cranial nerves.

Answer 10

Mixed cranial nerves are CN V (Trigeminal), CN VII (Facial), CN IX (Glossopharyngeal), CN X (Vagus).

Question 11

Describe the pathway and function of Cranial Nerve I.

Answer 11

CN I passes through the cribriform plate of the ethmoid bone, from olfactory receptor cells to the olfactory bulb, and terminates in the primary olfactory cortex in the medial temporal lobe. It carries afferent impulses for the sense of smell.

Question 12

Describe the pathway and function of Cranial Nerve II.

Answer 12

CN II arises from the retina of the eye, passes through the optic canals, converges at the optic chiasm, continues to the thalamus, and terminates at the visual cortex in the occipital lobe. It carries afferent impulses for vision.

Question 13

What is the function of Cranial Nerve III and its pathway?

Answer 13

CN III controls upward, downward, and medial eye movement, elevation of the upper eyelid, and movement of the eyeball. Its fibers extend from the ventral midbrain, pass through the superior orbital fissure, and go to the extrinsic eye muscles.

Question 14

What is the function of Cranial Nerve IV and its pathway?

Answer 14

CN IV innervates the superior oblique muscle, turning the eye out and down (inferolaterally). Its fibers emerge from the dorsal midbrain and enter the orbits via the superior orbital fissures.

Question 15

Describe the function and divisions of Cranial Nerve V.

Answer 15

CN V supplies sensory and motor innervation to the head and neck, with three divisions: ophthalmic (V1), maxillary (V2), and mandibular (V3). It conveys sensory impulses from the face and supplies motor fibers for mastication.

Question 16

What is the function of Cranial Nerve VI and its pathway?

Answer 16

CN VI innervates the lateral rectus muscle to abduct the eye. Its fibers leave the inferior pons and enter the orbit via the superior orbital fissure.

Question 17

Describe the function and pathway of Cranial Nerve VII.

Answer 17

CN VII controls facial expression, lacrimal and salivary glands, and taste from the anterior two-thirds of the tongue. Its fibers leave the pons, travel through the internal acoustic meatus, and emerge through the stylomastoid foramen to the face.

Question 18

Describe the function and divisions of Cranial Nerve VIII.

Answer 18

CN VIII is responsible for hearing and balance, with two divisions: cochlear (hearing) and vestibular (balance). Its fibers arise from the inner ear, pass through the internal acoustic meatus, and enter the brainstem at the pons-medulla border.

Question 19

What is the function of Cranial Nerve IX and its pathway?

Answer 19

CN IX controls part of the tongue and pharynx for swallowing, provides motor fibers to the parotid gland, and conducts taste and sensory impulses from the posterior tongue and pharynx. Its fibers emerge from the medulla and leave the skull via the jugular foramen

Question 20

What is unique about Cranial Nerve X and its function?

Answer 20

CN X is the only cranial nerve that extends beyond the head and neck, controlling the thoracic and abdominal organs and contributing to taste from the root of the tongue and epiglottis. Its fibers emerge from the medulla via the jugular foramen.

Question 21

What is the function of Cranial Nerve XI and its pathway?

Answer 21

CN XI innervates the trapezius and sternocleidomastoid muscles, moving the head and neck. It has a cranial root from the medulla and a spinal root from the spinal cord, passing into the cranium via the foramen magnum and leaving via the jugular foramen.

Question 22

Describe the function and pathway of Cranial Nerve XII.

Answer 22

CN XII provides motor innervation to the muscles of the tongue (except palatoglossus), contributing to swallowing and speech. Its fibers arise from the medulla and exit the skull via the hypoglossal canal.