Special Senses: Eye and Ear Anatomy and Function

Comprehensive vocabulary flashcards covering the anatomy and physiology of the special senses, specifically the eye and the ear, based on Lab Manual Chapter 18.

Caruncle

A protective feature of the eye that produces an oily secretion.

Conjunctiva

A thin membrane that covers the eye and secretes mucus.

Conjunctivitis

Inflammation of the conjunctiva, also known as "pink-eye."

Lacrimal gland

A gland that produces tears used to lubricate, cleanse, and protect the eye.

Lysozyme

An enzyme secreted in tears that helps protect and cleanse the eye.

Lateral rectus

An eye muscle that moves the eye laterally and is innervated by cranial nerve VI (abducens).

Medial rectus

An eye muscle that moves the eye medially and is innervated by cranial nerve III (oculomotor).

Superior rectus

An eye muscle that elevates the eye and is innervated by cranial nerve III (oculomotor).

Inferior rectus

An eye muscle that depresses the eye and is innervated by cranial nerve III (oculomotor).

Inferior oblique

An eye muscle that elevates the eye and turns it laterally; it is innervated by cranial nerve III (oculomotor).

Superior oblique

An eye muscle that depresses the eye and turns it laterally; it is innervated by cranial nerve IV (trochlear).

Sclera

Part of the fibrous tunic consisting of white avascular connective tissue (dense irregular CT).

Cornea

The transparent portion of the fibrous tunic that allows light to enter the eye.

Choroid

A blood-rich layer of the vascular tunic (uvea) containing melanocytes that absorb and refract light to prevent scattering.

Ciliary body

Part of the vascular tunic containing smooth ciliary muscles that change the shape of the lens.

Iris

The pigmented, smooth muscle portion of the eye that surrounds the pupil and controls the amount of light entering.

Optic disk

Known as the "blind spot," it is the area of the neural retina where rods and cones are absent.

Macula lutea

A yellow spot on the retina characterized by a high density of cones.

Fovea centralis

An area with high cone density that provides the greatest visual acuity.

Aqueous humor

A watery fluid found in the anterior cavity that is continually replaced.

Vitreous humor

A viscous fluid in the posterior cavity that helps maintain the eye's structure and refractive medium; it is produced only once and cannot be regenerated.

Crystalline fibers

Fibers that the simple cuboidal epithelium of the lens differentiates into; as more are deposited, focus can become impaired.

Myopic eye

A nearsighted eye condition that requires a concave lens for correction.

Hyperopic eye

A farsighted eye condition that requires a convex lens for correction.

Presbyopia

The loss of lens accommodation due to aging, where the lens loses its ability to change shape.

Pinna

Also called the auricle, it is a cartilaginous, skin-covered structure that directs sound waves into the auditory canal.

Ceruminous glands

Glands located in the external auditory canal that secrete wax, also known as cerumen.

Ossicles

The smallest bones in the body (malleus, incus, and stapes) that amplify vibrations for the inner ear.

Auditory tube

Also known as the pharyngotympanic tube, it connects the middle cavity with the nasopharynx to equalize air pressure.

Perilymph

The fluid that fills the osseous labyrinth of the inner ear.

Endolymph

A viscous fluid that fills the membranous labyrinth of the inner ear.

Spiral organ of Corti

The portion of the cochlea important for generating sound through the stimulation of hair cells.

Static Equilibrium

The perception of the location of the head when the body is stationary.

Dynamic equilibrium

The perception of motion or acceleration, including linear and angular acceleration.

Macula sacculi

An organ in the vestibule that lies vertically on the saccule wall and monitors vertical acceleration.

Macula utriculi

An organ in the vestibule that lies horizontally on the floor of the utricle and monitors front/back acceleration.

Kinocilium

The single true cilium found on each hair cell in the macula.

Otoliths

Granules of calcified protein located within the gelatinous otolithic membrane that weigh it down.

Crista ampullaris

The structure in the semicircular canals that monitors rotational equilibrium.

Cupula

A gelatinous structure in the ampulla that stands upright at rest and bends with the flow of endolymph to excite or inhibit hair cells.