Special Senses: Vision Study Guide

Vocabulary flashcards covering the accessory structures, extrinsic muscles, tunics, and internal structures of the human eye based on the vision review worksheet.

Palpebrae

The eyelids, which function to protect the eye and spread tears over the eye surface.

Eyelashes

Short hairs growing from the edges of the eyelids that protect the eyes from dust and debris.

Conjunctiva

The mucous membrane that covers the front of the eye and lines the inside of the eyelids.

Eyebrows

Hairs located above the eyes that prevent perspiration from reaching the eye and provide shade from sunlight.

Lacrimal Apparatus

The system of structures responsible for the production, distribution, and drainage of tears.

Extrinsic Eye Muscles

Six muscles attached to the sclera that control the movement of the eyeball.

Superior Rectus

An extrinsic eye muscle that moves the eyeball superiorly and medially.

Inferior Rectus

An extrinsic eye muscle that moves the eyeball inferiorly and medially.

Medial Rectus

An extrinsic eye muscle that moves the eyeball medially.

Lateral Rectus

An extrinsic eye muscle controlled by cranial nerve VI (Abducens) that moves the eyeball laterally.

Superior Oblique

An extrinsic eye muscle controlled by cranial nerve IV (Trochlear) that moves the eyeball inferior and laterally.

Inferior Oblique

An extrinsic eye muscle that moves the eyeball superior and laterally.

Cranial Nerve III (Oculomotor nerve)

The nerve that controls the Superior Rectus, Inferior Rectus, Medial Rectus, and Inferior Oblique extrinsic eye muscles.

Anterior Segment

The part of the eyeball located in front of the lens that contains aqueous humor.

Cataract

An eye condition that causes vision problems due to the lens or cornea becoming cloudy.

Posterior Segment

The part of the eyeball located behind the lens that contains vitreous humor.

Fibrous Tunic

The outermost layer of the eye containing the sclera and the cornea.

Vascular Tunic

The middle layer of the eye housing the lens, zonules (suspensory ligaments), choroid, and iris.

Nervous Tunic

The innermost layer of the eye housing the retina, optic disc, macula lutea, and fovea centralis.

Lens

The eye structure responsible for focusing images onto the retina.

Sclera

The white part of the eye which serves as the structure that extrinsic eye muscles are attached to.

Fovea Centralis

The eye structure known for being the area of highest visual acuity.

Optic Disc

The eye structure that creates a blind spot in vision because it lacks photoreceptor cells.

Rods

Photoreceptor cells in the retina that detect black, white, and gray colors.

Cones

Photoreceptor cells in the retina that detect colors.

Cornea

Transparent anterior portion of the fibrous tunic that functions to refract or bend light into the eye.

Iris

The pigmented part of the vascular tunic that regulates the size of the pupil and the amount of light entering the eye.

Pupil

The central opening of the iris through which light enters.

Ciliary Muscles

Muscles that control the tension of the zonules to change the shape of the lens for focusing.

Zonules (Suspensory Ligaments)

Ligaments that connect the ciliary body to the lens to hold it in place.

Retina

The light-sensitive inner surface of the eye containing the photoreceptor cells (rods and cones).