Worksheet 2: Midbrain and Hindbrain

Inferior Colliculi

Paired structures in the midbrain involved in auditory processing, playing a crucial role in the auditory reflexes and sound localization.

Superior Colliculi

Paired structures in the midbrain that are primarily involved in visual processing and the coordination of eye movements.

Periaqueductal Gray Matter

species survival instincts such as fighting and mating, also mediating analgesic effects

Substantia Nigra

production of dopamine, affecting motor function

Red Nucleus

A midbrain structure involved in motor coordination, particularly in the control of limb movements and reflexes.

Pons

Sleep/wake regulation and respiration

Cerebellum

Coordinating movements - receives visual, auditory, vestibular, and somatosensory information

Medulla Oblongata

Controls autonomic functions such as breathing, heart rate, and blood pressure.

Reticular Formation

plays a role in sleep and arousal, attention, muscle tone, movement, and various vital reflexes.

Olfactory Nerve - I

A sensory nerve responsible for the sense of smell, transmitting information from the nasal cavity to the brain.

Optic Nerve - II

A sensory nerve that transmits visual information from the retina to the brain, enabling sight.

Oculomotor Nerve - III

A motor nerve that controls most of the eye's movements, including constriction of the pupil and maintaining an open eyelid.

Trochlear Nerve - IV

A motor nerve that innervates the superior oblique muscle of the eye, enabling downward and lateral movement.

Trigeminal Nerve - V

A mixed nerve responsible for sensation in the face and motor functions such as biting and chewing.

Abducens Nerve - VI

A motor nerve that controls the lateral rectus muscle of the eye, allowing for outward gaze.

Facial Nerve - VII

A mixed nerve that controls the muscles of facial expression and provides taste sensations from the anterior two-thirds of the tongue.

Vestibulocochlear Nerve - VIII

A sensory nerve responsible for hearing and balance, transmitting sound and equilibrium information from the inner ear to the brain.

Glossopharyngeal Nerve - IX

A mixed nerve that innervates the pharynx, provides taste sensations from the posterior one-third of the tongue, and contributes to the gag reflex.

Vagus Nerve - X

A mixed nerve that innervates the thoracic and abdominal organs, regulating functions such as heart rate, digestion, and respiratory rate.

Accessory Nerve - XI

A motor nerve that controls the sternocleidomastoid and trapezius muscles, facilitating head movement and shoulder elevation.

Hypoglossal Nerve - XII

A motor nerve that controls tongue movements, essential for speech and swallowing.