| A | B |
|---|
| eye | receptor organ of sight |
| adnexa oculi | group term for the extraocular structures of the eye |
| orbit | bony cavity of the skull that contains and protects the eyeball and adnexa |
| canthus | angle where upper and lower eyelids meet |
| conjunctiva | transparent mucous membrane that lines the underside of the eyelid and covers the exposed surface of the sclera |
| lacrimal glands | glands found above the outer corner of the eye that produce tears |
| lacrimal ducts | collect tears into the lacrimal sac |
| nasolacrimal duct | duct that drains excess tears into the nasal cavity |
| sclera | tough fibrous outer layers of the eye; white of the eye |
| cornea | transparent anterior surface of the eye that extends like a dome over the iris and pupil; focuses light rays |
| iris | pigmented muscular layer that surrounds the pupil |
| pupil | circular opening in the center of the iris |
| lens | clear, flexible, curved structure that focuses images on the retina |
| choroid | opaque middle layer of the eye wall that provides blood supply |
| ciliary body | set of muscles and ligaments that adjust the thickness of the lens to refine focus |
| retina | innermost layer of the eye wall that contains rods and cones (receptors for light) |
| rods | light sensitive cells that respond to light intensity (black and white) |
| cones | light sensitive cells that respond to colour |
| macula | yellow area in the center of the retina that contains the highest concentration of receptor cells |
| fovea centralis | pit in the center of the macula that contains the majority of cone receptors; sharpest colour vision |
| optic disk | area where nerves enter the retina; natural blind spot |
| optic nerve | second cranial nerve; transmits nerve impulses from the retina to the brain |
| aqueous chamber | area between the cornea and the lens |
| vitreous chamber | area between the lens and the retina |
| aqueous humor | watery fluid that fills the aqueous chambers |
| vitreous humor | jelly-like fluid that fills the vitreous chamber; helps eye hold its shape |
| accomodation | changes made to the size and shape of the lens to allow for focus adjustments |
| convergence | simultaneous inward movement of the eyes as objects come nearer (preserves binocular vision) |
| refraction | ability of the lens, cornea and fluids to bend light rays |
| visual acuity | ability to distinguish object details at a distance |
| ophthalmologist | medical doctor who specializes in diseases and disorders of the eye |
| optometrist | non-medical doctor who measures vision and prescribes corrective lenses |
| pinna; auricle | visible outer portion of ear; conducts sound waves into auditory canal |
| external auditory canal | carries sound waves from the pinna to the middle ear; contains guard hairs and cerumen |
| cerumen | ear wax |
| tympanic membrane | eardrum; membrane that conducts sound to the ossicles by vibrating |
| auditory ossicles | bones of the middle ear |
| malleus | hammer; first bone of the middle ear |
| incus | anvil; second bone of the middle ear |
| stapes | stirrup; third bone of the middle ear |
| eustachian tubes | narrow tubes that connect the middle ear to the nasal cavity; equalize air pressure |
| outer ear | consists of the pinna and auditory canal; collects signals |
| middle ear | area containing the auditory ossicles; amplifies signals |
| inner ear; labyrinth | contains the sensory receptors for hearing and balance |
| oval window | membrane that separates the middle ear from theinner ear |
| cochlea | spiral passage that leads from the oval window and contains the Organ of Corti |
| semicircular canals | tubes that contain receptors for movement and positioning that help the body maintain balance (equilibrium) |
| otolaryngologist | ear, nose and throat specialist (medical doctor) |
| audiologist | specializes in measuring hearing function and rehabilitating people with hearing impairments |
