Cranial Nerves Overview

Twelve pairs of nerves connecting the brain to structures in the head and neck.

Groups of neurons in the brain that control cranial nerves.

Brain regions receiving sensory information from cranial nerves.

Brain regions sending motor signals to cranial nerves.

Cranial nerves carry both sensory (afferent) and motor (efferent) information for head and neck.

Cranial nerve responsible for sense of smell.

Cranial nerve responsible for sight.

Cranial nerve that innervates smooth muscles and glands of the cardiovascular, respiratory, and gastrointestinal systems.

Cranial nerve controlling movement of head and shoulder muscles (sternomastoid and trapezius).

Cranial nerve controlling tongue movements (intrinsic and extrinsic muscles).

The first two cranial nerves connect directly to the forebrain; the rest connect to the brainstem.

Controls organs like the heart, lungs, and gut.

Located in the midbrain, near the superior colliculus.

Controls eye muscles (except superior oblique & lateral rectus).

Innervates the superior oblique eye muscle.

In the caudal pons, beneath the fourth ventricle.

Controls the lateral rectus eye muscle.

Located in the medulla.

Innervates tongue muscles.

Controls mastication muscles (chewing) and others.

The part of the light reflex pathway that carries information from the eye to the brain.

The pupillary constriction in the non-illuminated eye during a light reflex test.

A brain region that receives visual input related to the light reflex in the brain.

A brain nucleus that controls pupil constriction via parasympathetic system.

Adjusting the eye's focus for viewing objects at different distances.

Turning the eyes inward to focus on a nearby object.

Cranial nerve that controls the superior oblique eye muscle.

Eye muscle that rotates the eye downward and outward.

The superior oblique muscle depresses the visual axis when the eye is adducted (turned inwards towards the nose).

The abducens nucleus is located in the caudal pons, beneath the floor of the fourth ventricle.

The abducens nerve (cranial nerve VI) originates in the pons, exits the brainstem ventrally, passes through the cavernous sinus, and enters the orbit via the superior orbital fissure.

The abducens nerve controls the lateral rectus muscle, which is responsible for abducting (moving outward) the eye.

The abducens nerve exits the brainstem ventrally at the junction between the pons and the pyramid of the medulla.

The abducens nerve, like the trochlear nerve, contains only somatic motor neurons, meaning it carries signals for voluntary movement.

The trochlear nerve controls the superior oblique muscle, which depresses the eye during adduction, while the abducens nerve controls the lateral rectus muscle, which abducts (moves outward) the eye.

A bundle of nerve fibers carrying auditory information from the brainstem to the midbrain.

A midbrain structure that receives auditory information from the lateral lemniscus and relays it to the thalamus.

A thalamic nucleus that receives auditory signals from the inferior colliculus and sends them to the auditory cortex.

An organized arrangement of sound frequencies in the auditory pathway, mirroring the cochlea's tonotopic map.

The area surrounding the primary auditory cortex, responsible for interpreting and assigning meaning to sounds.

A region in the temporal lobe involved in language comprehension and understanding.

Muscles in the middle ear that protect the ear from loud noises by contracting in response to sound.

The part of the temporal lobe that receives and processes auditory information from the thalamus.