Cranial Nerves Overview

Flashcards covering key concepts about cranial nerves, their functions, damage consequences, and conditions related to them.

What are the cranial nerves and how many pairs are there?

There are 12 pairs of cranial nerves that arise from the brain, exit through foramina, and lead to muscles, glands, and sense organs in the head and neck.

Which cranial nerves have ipsilateral input and output?

All cranial nerves except for CN II (Optic) and CN IV (Trochlear) have ipsilateral input and output.

What is the function of the Olfactory Nerve (I)?

The Olfactory Nerve is responsible for the sense of smell.

What are the consequences of damage to the Olfactory Nerve?

Damage to the Olfactory Nerve can cause an impaired sense of smell.

What is the primary function of the Optic Nerve (II)?

The Optic Nerve provides vision.

What happens if the Optic Nerve is damaged?

Damage to the Optic Nerve can cause blindness in the visual field.

What functions are performed by the Oculomotor Nerve (III)?

The Oculomotor Nerve is involved in eye movement, opening of the eyelid, constriction of the pupil, and focusing.

What are the effects of damage to the Oculomotor Nerve?

Damage can cause a drooping eyelid, dilated pupil, double vision, difficulty focusing, and inability to move the eye in certain directions.

What is the role of the Trochlear Nerve (IV)?

The Trochlear Nerve is responsible for eye movement of the superior oblique muscle.

What are the symptoms of damage to the Trochlear Nerve?

Damage causes double vision and inability to rotate the eye inferolaterally.

What is the main function of the Trigeminal Nerve (V)?

The Trigeminal Nerve provides sensory input from the face and controls muscles of mastication.

What results from damage to the Trigeminal Nerve?

Damage produces loss of sensation and impaired chewing.

What is the role of the Abducens Nerve (VI)?

The Abducens Nerve provides eye movement, specifically for the lateral rectus muscle.

What symptoms arise from damage to the Abducens Nerve?

Damage results in the inability to rotate the eye laterally and causes the eye to rotate medially at rest.

What functions does the Facial Nerve (VII) have?

The Facial Nerve controls facial expressions, salivary glands, and sensory taste on the anterior two-thirds of the tongue.

What damage occurs to the Facial Nerve?

Damage can cause sagging facial muscles and a disturbed sense of taste.

What is the function of the Vestibulocochlear Nerve (VIII)?

It provides hearing and a sense of balance.

What happens if the Vestibulocochlear Nerve is damaged?

Damage can lead to deafness, dizziness, nausea, loss of balance, and nystagmus.

What are the roles of the Glossopharyngeal Nerve (IX)?

The Glossopharyngeal Nerve is involved in swallowing, salivation, gagging, and sensations from the posterior one-third of the tongue.

What effects arise from damage to the Glossopharyngeal Nerve?

Damage results in loss of bitter and sour taste and impaired swallowing.

What is the primary function of the Vagus Nerve (X)?

The Vagus Nerve is responsible for swallowing, speech, and regulation of viscera.

What are the consequences of damage to the Vagus Nerve?

Damage can cause hoarseness or loss of voice and impaired swallowing.

What does the Accessory Nerve (XI) control?

It controls swallowing and movements of the head, neck, and shoulders.

What happens if the Accessory Nerve is damaged?

Damage results in impaired movement of the head, neck, and shoulder, with the head turning towards the injured side.

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

The Hypoglossal Nerve controls tongue movements for speech, food manipulation, and swallowing.

What occurs if the Hypoglossal Nerve is damaged?

If both are damaged, the tongue cannot protrude; if one side is damaged, the tongue deviates towards the injured side.

What is Trigeminal Neuralgia?

Trigeminal Neuralgia is a condition characterized by recurring episodes of intense stabbing facial pain.

What typically triggers Trigeminal Neuralgia attacks?

Attacks can be triggered by touch, drinking, washing the face, or brushing teeth.

What is Bell’s Palsy?

Bell’s Palsy is a disorder of the facial nerve causing paralysis of facial muscles on one side.

Who is most commonly affected by Bell’s Palsy?

It disproportionately affects pregnant women and people with diabetes or upper respiratory ailments.