W1 L7and 8 Peripheral Distribution of Cranial Nerves VII to XII

CN VII (Facial Nerve)

Innervates muscles for facial expressions, carries taste sensations from the anterior two-thirds of the tongue, and stimulates salivary and lacrimal glands.

CN VIII (Vestibulocochlear Nerve)

Responsible for hearing and balance; conveys sound information from the cochlea and body position from the vestibular apparatus.

CN IX (Glossopharyngeal Nerve)

Supplies sensory information from the oropharynx, taste sensations from the posterior one-third of the tongue, and motor function to the stylopharyngeus muscle.

CN X (Vagus Nerve)

Controls muscles in the palate, pharynx, and larynx; regulates heart rate and gastrointestinal functions through visceral motor fibers.

CN XI (Spinal Accessory Nerve)

Primarily a motor nerve that innervates the sternocleidomastoid and trapezius muscles, facilitating head movement and shoulder elevation.

CN XII (Hypoglossal Nerve)

Exclusively motor; controls tongue movements for speech and swallowing.

Horner’s Syndrome

A condition characterized by ptosis, miosis, and anhidrosis, resulting from disruption of sympathetic supply to the eye.

Parasympathetic Functions in Cranial Nerves

Cranial Nerves III, VII, IX, and X play critical roles in regulating functions such as pupil constriction, tear production, and heart rate.

What is the function of CN VII (Facial Nerve)?

It innervates muscles for facial expressions, carries taste sensations from the anterior two-thirds of the tongue, and stimulates salivary and lacrimal glands.

Which nerve is responsible for hearing and balance?

CN VIII (Vestibulocochlear Nerve) is responsible for hearing and balance; it conveys sound information from the cochlea and body position from the vestibular apparatus.

What sensory information does the CN IX (Glossopharyngeal Nerve) provide?

It supplies sensory information from the oropharynx and taste sensations from the posterior one-third of the tongue.

What are the primary functions of the CN X (Vagus Nerve)?

It controls muscles in the palate, pharynx, and larynx, and regulates heart rate and gastrointestinal functions through visceral motor fibers.

What muscles does the CN XI (Spinal Accessory Nerve) innervate?

It primarily innervates the sternocleidomastoid and trapezius muscles, facilitating head movement and shoulder elevation.

What is the role of the CN XII (Hypoglossal Nerve)?

It is exclusively motor and controls tongue movements for speech and swallowing.

What are the symptoms of Horner’s Syndrome?

Symptoms include ptosis, miosis, and anhidrosis, resulting from disruption of sympathetic supply to the eye.

Which cranial nerves are involved in parasympathetic functions?

Cranial Nerves III, VII, IX, and X are involved in parasympathetic functions such as pupil constriction, tear production, and heart rate regulation.

What is ptosis and which syndrome is it associated with?

Ptosis is drooping of the upper eyelid and is associated with Horner’s Syndrome.

What cranial nerve would be damaged if a person cannot taste from the anterior two-thirds of the tongue?

Damage to CN VII (Facial Nerve) would result in loss of taste in the anterior two-thirds of the tongue.

Which nerve controls the muscle responsible for swallowing?

The CN XII (Hypoglossal Nerve) controls the muscles of the tongue involved in swallowing.

How does the Vagus nerve affect heart rate?

The Vagus Nerve (CN X) regulates heart rate by its visceral motor fibers that innervate the heart.