Chapter 15 Main points 2

This set of flashcards covers key vocabulary terms related to the sensory systems of taste, hearing, and balance, based on the lecture notes provided.

Dissolved chemicals

Detected by receptor cells in taste buds.

Gustatory epithelial cells

Receptor cells of the taste buds that have gustatory hairs.

Gustatory hairs

Microvilli that serve as the receptor regions for taste.

Tastants

Food chemicals that bind to receptors on the gustatory cells.

Five basic taste qualities

Sweet, sour, salty, bitter, and umami.

Cranial nerves involved in taste

VII, IX, and X, which send impulses to the solitary nucleus of the medulla.

External ear

Composed of the auricle and external acoustic meatus.

Tympanic membrane

The boundary between the outer and middle ears that transmits sound waves.

Ossicles

Tiny bones in the middle ear that amplify sound vibrations.

Bony labyrinth

Part of the internal ear that contains perilymph.

Membranous labyrinth

Contains endolymph and is suspended within the bony labyrinth.

Vestibule

Contains the saccule and utricle in the internal ear.

Semicircular canals

Three canals that contain semicircular ducts and are involved in balance.

Cochlea

Houses the cochlear duct and contains the spiral organ for hearing.

Basilar membrane

Membrane where hair cells rest in the cochlear duct.

Stereocilia

Hair-like structures on hair cells that respond to sound waves.

Sound wave

A pressure wave that stimulates mechanosensitive cochlear hair cells.

Wavelength

Distance from crest to crest in a sound wave, affecting frequency.

Frequency

Measured in hertz and perceived as pitch.

Amplitude of sound

Height of the sine wave, indicating sound intensity.

Decibels

Unit of measure for sound intensity.

Cochlear nerve

Carries auditory information to the brain.

Cochlear nuclei

Part of the medulla where cochlear nerve impulses are sent.

Medial geniculate nucleus

Thalamic nucleus that relays sound information to the auditory cortex.

Auditory processing

Analytic process where each tone is perceived separately.

Pitch perception

Related to the position of excited hair cells along the basilar membrane.

Maculae

Receptors for linear acceleration and gravity in the vestibular apparatus.

Crista ampullaris

Receptor within semicircular ducts responding to angular acceleration.

Otolith membrane

Membrane that moves with linear movements, affecting hair cells.

Conduction deafness

Results from interference with sound vibration conduction.

Sensorineural deafness

Reflects damage to neural structures involved in hearing.

Tinnitus

Early sign of sensorineural deafness, possibly due to inflammation.

Ménière's syndrome

Disorder of the membranous labyrinth causing tinnitus, deafness, and vertigo.

Chemical senses

Sharpest at birth and decline with age as receptor cells are replaced more slowly.

Congenital eye problems

Uncommon issues that can cause blindness, often linked to maternal rubella.

Otic placode

Ectodermal structure that develops into the membranous labyrinth of the ear.

Presbycusis

Age-related loss of hearing that occurs in the 60s and 70s.