Chap 17 Sensory

Accommodation

Normal refractory adjustment of the eye to focus on an object from far to near

Acoustic neuroma

Benign tumor arising from the acoustic vestibulocochlear nerve in the brain

Amblyopia

Decreased visual acuity often in a single eye and appearing in children; lazy eye

Anisocoria

Inequality in the size of pupils

Anterior chamber

Area of the eye behind the cornea and in front of the lens and iris, containing the aqueous humor

Aphakia

Absence of the lens of the eye

Astigmatism

Defective curvature of the cornea or lens of the eye

Atrophy of the retina

Bilateral degeneration of the retina, causing progressive vision loss

Auditory canal

Channel that leads from the pinna to the eardrum (external auditory meatus)

Auditory meatus

Auditory canal (def.)

Auditory nerve fibers

Carry impulses from the inner ear to the brain. They compose the vestibulocochlear nerve

Aural discharge

Fluid or material from the ear

Auricle

Protruding part of the external ear; pinna

Barotitis

Inflammation of ear due to pressure (atmospheric changes)

Binocular vision

The ability to focus the two eyes in a coordinated manner in the occipital lobe of the brain in order to see one image

Blepharochalasis

relaxation of the eyelid

Cataract

Clouding of the lens, causing decreased vision

Cerumen

Waxy substance secreted by the external ear; earwax

Chalazion

Small, hard, cystic mass (granuloma) on the eyelid

Cholesteatoma

Collection of skin cells and cholesterol in a sac within the middle ear

Choroid

Middle, vascular layer of the eye, between the retina and the sclera

Ciliary body

Structure surrounding the lens that connects the iris to the choroid. It contains ciliary muscles, which control the shape of the lens, and it secretes aqueous humor

Cochlea

Snail-shaped, spirally wound tube in the inner ear; contains hearing-sensitive receptor cells

Cones

Photoreceptor cells in the retina that transform light energy into a nerve impulse. They're responsible for color and central vision

Conjunctiva

Delicate membrane lining the eyelids and covering the eyeball up to the cornea

Conjunctivitis

Inflammation of the conjunctiva

Cornea

Fibrous transparent layer of clear tissue that extends over the anterior portion of the eyeball

Dacryoadenitis

Inflammation of the tear glands

Diabetic retinopathy

Disease of the retina caused by diabetes mellitus; micro-aneurysms, hemorrhages, dilation of the retinal veins, and neovascularization (new blood vessels) in the retina

Diplopia

Double vision

Dysphonia

Abnormal voice or sound produced when speaking

Emmetropia

Clinical term for perfect vision; normal refractive condition of the eye in which with accommodation relaxed parallel rays of light are all brought accurately to a focus upon the retina

Endolymph

Fluid within they labyrinth (canals): of the inner ear, conducts sound waves

Esotropia

Turning inward of one or both pupils, "cross eyes"

Eustachian tube

Channel between the middle ear and the throat; auditory tube

Exotropia

Turning to the side or outward of one or both pupils

Fovea centralis

Tiny pit or depression in the retina that is the region of clearest vision

Glaucoma

Increased intraocular pressure results in damage to the retina and optic nerve with loss of vision

Hemianopsia

Absence of vision for one half, right or left, of an individual's field of vision

Hordeolum

Stye; small, superficial white nodule along lid margin due to infection of a sebaceous gland

Incus

Small, anvil-shaped bone (ossicle) in the middle ear; second ossicle

Iris

Pigmented (colored) layer of the eye

Iritis

Inflammation of the iris of the eye

Labyrinth

Maze-like series of canals of the inner ear; cochlea, vestibule, and semicircular canals

Labyrinthitis

Inflammation of the inner ear

Lens

Transparent, biconvex body behind the pupil of the eye. It bends (refracts) light rays to bring them into focus on the retina

Macrotia

Abnormally large ears

Macula

Small oval region on the retina near the optic disc; contains the fovea centralis, which is the area clearest vision

Macular degeneration

Progressive damage to the macula of the retina and resulting in loss of central vision

Malleus

Hammer-shaped, small bone (ossicle) in the middle ear; first ossicle

Mastoiditis

Inflammation and infection of the mastoid process just behind the ear

Megakaryocyte

Large, giant cell with a big nucleus; platelet precursor found in the bone marrow

Ménière disease

Disorder of the labyrinth of the inner ear; elevated endolymph pressure within the cochlea (cochlear hydrops) and semicircular canals (vestibular hydrops)

Myopia

Nearsightedness; vision condition in which close objects are seen more clearly than objects that are far

Myring/o

Tympanic membrane (eardrum)

Optic chiasm

Point at which optic nerve fibers cross in the brain

Organ of Corti

Sensitive auditory receptor area found in the cochlea of the inner ear

Ossicle

Small bone in the middle section of the ear; malleus, incus, and stapes are ossicles

Otomycosis

Fungal infection of the ear

Otopyorrhea

Discharge of pus from the ear

Oval window

Membrane between the middle ear and the inner ear

Palpebr/o

Eyelid

Perilymph

Fluid contained in the labyrinth (canals of the inner ear)

Photophobia

Sensitivity to light

Photopsia

Bright flashes of light

Posterior chamber

space between the back of the iris and the front of the vitreous chamber; filled with aqueous humor

Presbyopia

Impairment of vision as a result of old age

Resbycusis

Progressive loss of hearing, occurring in middle and older age

Pupil

Central opening of the eye, surrounded by the iris through which light rays pass. It appears dark

Refraction

Bending of light rays by the cornea, lens, and fluids of the eye to bring the rays into focus on the retina

Rods

Photoreceptor cells of the retina essential for vision in low light and for peripheral vision

Salpingitis

Inflammation of a fallopian tube

Sclera

Tough, white outer coat of the eyeball

Scleral buckle

Suture of a silicone band to the sclera over a detached potion of the retina

Scleritis

Inflammation of the sclera

Serous otitis media

Noninfectious inflammation with accumulation of serous fluid. Often results from a dysfunctional or obstructed auditory tube.

Stapes

Small, stirrup-shaped bone in the middle ear; third ossicle

Steatoma

Fatty tumor

Strabismus

Abnormal deviation of the eye; esotropia or exotropia are examples

Suppurative otitis media

Inflammation of the middle ear with bacterial infection and pus collection

Tinnitus

Sensation of noises in the ears without an external source

Tympanic membrane

Membrane between the outer and the middle ear; also called the eardrum

Utricle

The larger of two sacs within the vestibule in the inner ear that helps maintain equilibrium

Uveitis

Inflammation of the uvea, which is the vascular layer of the eye (including the iris, choroid, and ciliary body)

Vertigo

Sensation of irregular or whirling motion either of oneself or of external objects

Vestibule

Central cavity of the labyrinth in the inner ear; connecting the cochlea and semicircular canals

Vitreous humor

Soft, jelly-like material behind the lens in the vitreous chamber; helps maintain the shape of the eyeball

Xerophthalmia

Condition of excessive dryness of the eye