Special Senses: Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering anatomy, physiology, and clinical terms related to olfaction, gustation, vision, and the auditory–vestibular system.

Special senses

Olfaction, gustation, vision, equilibrium, and hearing that send information to the CNS.

Olfaction

Sense of smell mediated by olfactory organs in the nasal cavity.

Olfactory epithelium

Surface layer containing cilia (olfactory hairs) where odorant molecules bind to trigger action potentials.

Lamina propria (olfactory)

Connective tissue beneath the olfactory epithelium housing Bowman’s glands that dissolve odorants.

Anosmia

Loss or absence of the sense of smell.

Gustation

Sense of taste involving gustatory epithelial cells and tongue papillae.

Gustatory epithelial cells

Taste receptor cells replaced every 10–14 days that respond to chemical tastants.

Papillae

Surface projections on the tongue: fungiform, foliate, circumvallate, and filiform.

Taste buds

Clusters of gustatory cells innervated by cranial nerves VII, IX, and X that synapse in the solitary nucleus.

Sweet taste

Detects sugars, alcohols, and some amino acids; signals energy-rich foods.

Salty taste

Detects sodium ions; important for electrolyte balance.

Sour taste

Responds to acids in foods such as citrus.

Bitter taste

Sensitive to alkaloids like caffeine and quinine; often a toxin warning.

Umami

“Delicious” taste associated with glutamate-rich foods such as cheese and soy sauce.

Water receptors

Pharyngeal receptors that help detect thirst and hydration status.

Dysgeusia

Distorted or lost sense of taste.

Vision

Dominant sense providing information on distance, color, movement, and shape.

Eyelids (palpebrae)

Skin folds that blink to lubricate and protect the eye; bordered by eyelashes.

Conjunctiva

Transparent membrane covering the eye except the cornea.

Conjunctivitis

Inflammation of the conjunctiva due to bacteria, viruses, allergens, or chemicals.

Sclera

“White” of the eye composed of collagen and elastic fibers with few blood vessels.

Cornea

Avascular, transparent front part of the eye responsible for two-thirds of focusing power.

Snellen chart

Eye chart used to assess visual acuity; standard rating is 20/20.

Pupil

Opening that regulates light entering the eye.

Iris

Colored ring of muscle that adjusts pupil size for light regulation.

Fovea centralis

Area of highest cone density in the retina providing sharp central vision.

Optic nerve (CN II)

Carries visual signals from the retina to the brain.

Retina

Inner eye layer with pigmented layer absorbing light and neural layer containing photoreceptors.

Rods

Photoreceptors for black-and-white and low-light (night) vision.

Cones

Photoreceptors responsible for color and sharp vision.

Vitamin A

Essential nutrient for maintaining photoreceptor health and overall eye function.

Vitamin E

Antioxidant vitamin that supports eye health.

Astigmatism

Irregular curvature of cornea or lens causing blurred or distorted vision.

Myopia (nearsightedness)

Condition where distant objects appear blurry; eye focuses images in front of retina.

Hyperopia (farsightedness)

Condition where close objects appear blurry; eye focuses images behind retina.

LASIK

Refractive surgery using lasers to reshape the cornea and correct vision errors.

Scotoma

Permanent blind spot in the visual field due to optic nerve or retinal damage.

Glaucoma

Group of conditions causing optic nerve compression and vision loss, often from high intraocular pressure.

Macular degeneration

Degenerative condition of the central retina leading to loss of central vision.

Auricle (pinna)

Visible external part of the ear that collects sound waves.

External acoustic meatus

Ear canal containing cerumen (earwax) that channels sound to the eardrum.

Tympanic membrane

Eardrum that vibrates in response to sound waves.

Auditory ossicles

Middle-ear bones—malleus, incus, stapes—that amplify vibrations.

Oval window

Membrane at the entrance to the inner ear where stapes transmits vibrations.

Round window

Membrane that relieves pressure in the inner ear after sound transmission.

Eustachian (auditory) tube

Canal connecting middle ear to nasopharynx to equalize pressure.

Cochlea

Spiral inner-ear structure housing the organ of Corti for hearing.

Vestibule

Inner-ear chamber involved in static balance and linear acceleration.

Semicircular canals

Three fluid-filled loops that detect rotational movements for balance.

Vestibulocochlear nerve (CN VIII)

Cranial nerve transmitting hearing and balance information to the brain.

Cerumen

Earwax produced in the external acoustic meatus for protection and lubrication.

Otitis media

Infection of the middle ear.

Vertigo

Sense of spinning or imbalance due to inner-ear disorders.

Meniere’s disease

Inner-ear disorder causing vertigo, hearing loss, and tinnitus.

Benign paroxysmal positional vertigo (BPPV)

Brief episodes of vertigo triggered by head position changes.

Organ of Corti

Sensory structure in the cochlea that converts vibrations into electrical signals.

Pitch

Perception of sound frequency measured in hertz (Hz); human range 20–20,000 Hz.

Loudness

Perception of sound amplitude measured in decibels (dB).

Timbre

Quality or color of sound that distinguishes different voices or instruments.