Ear & Eye


the curved protective layer through which light rays are admitted and refracted


maintains the shape of the eye and provides protection for inner parts; also referred to as the 'white' of the eye

Optic Nerve

nerve responsible for carrying impulses for the sense of sight from the retina to the brain

Vitreous Humor

A thick, gelatinous fluid found in the posterior segment of the eye (between the lens and the retina). The vitreous humor is only produced during fetal development and helps maintain intraocular pressure (the pressure inside the eyeball)


biconvex transparent body situated behind the iris in the eye; focuses light on the retina

Ciliary body

ring of muscle behind the peripheral iris that secretes aqueous humor and alters the shape of the lens for near or far vision


a ring of muscle tissue that forms the colored portion of the eye, regulates the amount of light that enters the eyeball

Pupillary dilator muscles

contract, enlarge pupil diameter

Pupillary constrictor muscles

constrict, reduce pupil diameter


provides blood supply and absorbs scattered light

Tapetum lucidum

Iridescent layer found in nocturnal animals for maximizing vision under low intensity light


receives light and converts it into nerve impulses

Optic DIsc

the point where the optic nerve enters the retina

Superior Rectus Muscle

rotates the eye superiorly and medially

Medial Rectus muscle

rotates the eye medially

Lateral Rectus Muscle

rotates the eye laterally

Inferior Rectus Muscle

rotates the eye inferiorly and medially

Superior Oblique Muscle

rotates the eye inferiorly and laterally

Inferior Oblique Muscle

rotates the eye superiorly and laterally


collects sound waves

External Auditory Meatus/Canal

directs sound waves to the tympanic membrane

Tympanic Membrane

vibrates upon reception of sound waves, transfers sound waves to the malleus

Auditory tube

equalizes air pressure on both sides of the tympanic membrane


receives vibrations from tympanic membrane and transfers them to the incus


receive vibrations from malleus and transfers them to the stapes


receives vibrations from incus and transfers them to the oval window

Oval Window

membrane at the entrance to the cochlea through which the ossicles transmit vibrations


the snail-shaped tube (in the inner ear coiled around the modiolus) where sound vibrations are converted into nerve impulses


middle part of the inner ear in front of the semicircular canals and behind the cochlea, contains the semicircular ducts, the utricle and the saccule

Semicircular canals

passages in the inner ear associated with maintaining equilibrium

Round WIndow

located just below the oval window; equalizes pressure in the inner ear

Vestibulocochlear Nerve

senses of hearing and balance/equilibrium