Anatomy & Physiology of Hearing

34 vocabulary flashcards covering major anatomical structures and physiological concepts involved in hearing, suitable for exam review.

Pinna (Auricle)

The funnel-shaped external ear structure that collects sound waves and directs them into the ear canal.

Darwin’s Tubercle (Auricular Tubercle)

Small cartilaginous bump on the outer rim of the pinna; a normal anatomical variation.

Helix

The prominent outer rim of the pinna.

Antihelix

Inner curved ridge of the pinna located parallel to the helix.

Tragus

Small cartilaginous projection anterior to the ear canal opening that helps screen sounds from behind.

Antitragus

Cartilaginous prominence opposite the tragus, above the ear lobe.

Lobule (Ear Lobe)

The soft, fleshy lower portion of the pinna lacking cartilage.

Intertragic Incisure

Notch between the tragus and antitragus.

External Auditory Canal (Ear Canal)

2–3 cm S-shaped passage transmitting sound from the pinna to the tympanic membrane.

Tympanic Membrane (Eardrum)

Thin, sensitive membrane that vibrates in response to sound and marks the boundary between external and middle ear.

Middle Ear

Air-filled cavity between the eardrum and oval window that houses the auditory ossicles.

Auditory Ossicles

Three small middle-ear bones (malleus, incus, stapes) that transmit and amplify vibrations from the tympanic membrane to the oval window.

Malleus (Hammer)

First ossicle attached to the tympanic membrane; articulates with the incus.

Incus (Anvil)

Middle ossicle that connects malleus to stapes.

Stapes (Stirrup)

Smallest bone in the body; footplate sits in the oval window to transmit vibrations to the inner ear.

Oval Window

Membrane-covered opening leading from middle ear to inner ear; amplifies and transmits sound to cochlear fluids.

Round Window

Secondary membrane-covered opening that allows cochlear fluid displacement during sound transmission.

Eustachian (Auditory) Tube

Canal linking middle ear to nasopharynx; equalizes air pressure across the tympanic membrane.

Inner Ear

Innermost part of the ear containing the cochlea, vestibular apparatus, and vestibulocochlear nerve.

Cochlea

Spiral, fluid-filled inner-ear structure that converts mechanical sound energy into electrical impulses.

Organ of Corti

Sensory epithelium atop the basilar membrane in the cochlea where hair cells transduce vibrations into nerve signals.

Basilar Membrane

Flexible membrane in the cochlea that vibrates with sound waves and supports the organ of Corti.

Stereocilia

Hair-like projections atop cochlear hair cells that bend to initiate electrical signaling.

Scala Vestibuli

Upper fluid-filled chamber of the cochlea through which sound waves first travel after the oval window.

Scala Tympani

Lower fluid-filled cochlear chamber that receives traveling waves and ends at the round window.

Vestibulocochlear Nerve (Cranial Nerve VIII)

Nerve carrying auditory and balance information from inner ear to brainstem.

Primary Auditory Cortex

Brain region in temporal lobe where conscious perception and processing of sound occur.

Sound Wave

Mechanical vibration of air molecules characterized by frequency and amplitude.

Frequency

Number of sound wave cycles per second, measured in hertz (Hz); determines pitch.

Pitch

Subjective perception of sound frequency; higher frequencies generate higher pitches.

Human Hearing Range

Approximate frequency span of 20 Hz to 20 000 Hz detectable by the average young adult.

Transduction (in Hearing)

Conversion of mechanical sound vibrations into electrical nerve impulses by cochlear hair cells.

Neural Transmission (Auditory Pathway)

Relay of electrical impulses from hair cells through auditory nerve nuclei to the primary auditory cortex.

Encoding of Sound

Neural processing steps that determine frequency (pitch), intensity (loudness), features, and spatial location of auditory signals.