Special senses Terminology

Special senses

The senses of vision, hearing, equilibrium, smell, and taste.

Retina

The light-sensitive layer at the back of the eye containing rods and cones.

Cornea

The transparent front surface of the eye that helps focus light.

Iris

The colored portion of the eye that controls pupil size.

Pupil

The opening in the center of the iris through which light enters.

Lens

A transparent structure that changes shape to focus light on the retina.

Optic nerve

Cranial nerve II; carries visual information from the retina to the brain.

Rod

A retinal photoreceptor specialized for dim-light and peripheral vision.

Cone

A retinal photoreceptor responsible for color and detailed vision.

Macula

The central area of the retina responsible for detailed central vision.

Fovea

The central region of the retina providing the sharpest vision.

Cataract

Clouding of the eye's lens that impairs vision.

Glaucoma

A group of eye disorders involving optic nerve damage.

Macular degeneration

A disorder involving degeneration of the macula and loss of central vision.

Conjunctivitis

Inflammation or infection of the conjunctiva; pink eye.

Myopia

Nearsightedness.

Hyperopia

Farsightedness.

Astigmatism

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

Presbyopia

Age-related loss of near focusing ability.

Otitis media

Inflammation or infection of the middle ear.

Otitis externa

Inflammation or infection of the external ear canal.

Tympanic membrane

The eardrum; vibrates in response to sound.

Cochlea

A spiral inner-ear structure responsible for hearing.

Semicircular canals

Inner-ear structures detecting rotational movement and helping maintain balance.

Vestibular system

The inner-ear system responsible for balance and spatial orientation.

Sensorineural hearing loss

Hearing loss caused by damage to the inner ear or auditory nerve.

Conductive hearing loss

Hearing loss caused by impaired sound transmission through the outer or middle ear.

Tinnitus

Perception of ringing, buzzing, or other sounds without an external source.

Vertigo

A sensation of spinning or movement, often caused by vestibular dysfunction.

Anosmia

Loss of the sense of smell.

Hyposmia

Reduced ability to smell.

Ageusia

Loss of the sense of taste.

Dysgeusia

Altered or distorted sense of taste.

Olfactory nerve

Cranial nerve I; responsible for smell.

Vestibulocochlear nerve

Cranial nerve VIII; responsible for hearing and balance.

Taste buds

Sensory structures containing receptor cells for taste.

Olfactory receptors

Sensory receptors that detect odor molecules.

Lacrimal glands

Glands that produce tears.

Conjunctiva

A thin membrane covering the front of the eye and inner eyelids.