The presence of air in the veins, which can lead to cardiac arrest if it enters the heart.

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The light-sensitive area of the eye where images are projected; a layer of cells at the back of the eye that changes the light image into electric impulses, which are carried by the optic nerve to the brain.

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The joint formed where the mandible and cranium meet, just in front of the ear.

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The small, rounded, fleshy bulge that lies immediately anterior to the ear canal.

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A cranial nerve that transmits visual information to the brain.

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The external, visible part of the ear.

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Separation of the retina from its attachments at the back of the eye.

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The circular opening in the middle of the iris that admits light to the back of the eye.

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The tough, fibrous, white portion of the eye that protects the more delicate inner structures.

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The prominent bony mass at the base of the skull about 1 inch (2.5 cm) posterior to the external opening of the ear.

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Naturally occurring uneven pupil size.

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The eyeball.

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A characteristic crackling sensation felt on palpation of the skin, caused by the presence of air in soft tissues.

(a)  

A fracture of the orbit or of the bones that support the floor of the orbit.

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The eardrum; a thin, semitransparent membrane in the middle ear that transmits sound vibrations to the internal ear by means of auditory ossicles.

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The muscle and surrounding tissue behind the cornea that dilate and constrict the pupil, regulating the amount of light that enters the eye; pigment in this tissue gives the eye its color.

(a)  

Layers of bone within the nasal cavity.

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The transparent tissue layer in front of the pupil and iris of the eye.

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Inflammation of the conjunctiva.

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The transparent part of the eye through which images are focused on the retina.

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The muscles on either side of the neck that allow movement of the head.

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The glands that produce fluids to keep the eye moist; also called tear glands.

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The ear canal; leads to the tympanic membrane.

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The delicate membrane that lines the eyelids and covers the exposed surface of the eye.

(a)