5.2 Special Senses: Hearing, Equilibrium, and Balance

These flashcards cover key terms and concepts related to the special senses of hearing, equilibrium, and balance as discussed in the lecture.

External Ear

The outer part of the ear that consists of the auricle and the auditory canal.

Middle Ear

Also known as the tympanic cavity, it houses the ossicles and connects to the nasopharynx via the Eustachian tube.

Inner Ear

Contains the cochlea and vestibular system, responsible for hearing and balance.

Tympanic Membrane

Also known as the eardrum, it vibrates in response to sound and separates the external ear from the middle ear.

Ossicles

Three small bones in the middle ear (malleus, incus, stapes) that transmit sound vibrations to the inner ear.

Cochlea

A spiral-shaped organ in the inner ear that contains the cochlear duct and is responsible for hearing.

Semicircular Canals

Three fluid-filled structures in the inner ear that help with balance and detect rotational movements.

Vestibular System

Part of the inner ear that is responsible for providing the sense of balance and spatial orientation.

Endolymph

Fluid contained within the membranous labyrinth of the inner ear, involved in hearing and balance.

Perilymph

Fluid located in the bony labyrinth of the inner ear, surrounding the membranous labyrinth.

Hair Cells

Sensory cells located in the inner ear that respond to mechanical stimuli and are involved in the mechanics of hearing and balance.

Kinocilium

The tallest stereocilia in hair cells; important for the mechanotransduction process.

Stereocilia

Hair-like projections on hair cells that detect movement and are involved in the generation of nerve impulses.

Nerve Impulse

An electrical signal sent from hair cells to the brain to interpret sound or balance stimuli.

Eustachian Tube

A tube that connects the middle ear to the nasopharynx and helps equalize pressure in the ear.

Basilar Membrane

A membrane in the cochlea that vibrates in response to sound waves and stimulates hair cells for hearing.

Auditory Pathway

The pathway that carries auditory information from the cochlea through the auditory nerve to the auditory cortex in the brain.

Tectorial Membrane

A membrane that lies above the hair cells in the cochlea and interacts with them to facilitate the sensation of hearing.

Vestibular Nuclei

Clusters of neurons in the brain that process balance and equilibrium information.