Key Terms

acromegaly

rare hormonal disorder that occurs when the pituitary gland produces an excessive amount of growth hormone (GH)

adenoids

lymphoid tissue that traps and destroys invading pathogens that enter during inhalation

adenoma

noncancerous tumor

amblyopia (also, lazy eye)

reduced vision in one eye due to improper development

anisocoria

unequal pupil sizes in both eyes

astigmatism

blurred or distorted vision due to an irregularly shaped cornea or lens

autoimmune disease

occurs when the body’s immune system attacks healthy cells and tissues

Bell palsy

neurological disorder characterized by the sudden onset of facial muscle weakness or paralysis

candidiasis (also, thrush)

fungal infection that appears as white patches

cataract

clouding of the eye’s natural lens

cauliflower ear

deformed ear, resembling cauliflower, due to repeated trauma to the ear

cerumen

earwax

cervical vertebrae

series of seven small bones that make up the upper part of the vertebral column, also known as the spine

chalazion

noninfectious bump on the eyelid caused by a blocked oil gland

ciliary muscle

controls the shape of the lens to help with focusing on near and distant objects

cleft lip

birth defect that involves a partial or complete failure of the right and left portions of the upper lip to fuse together, leaving a cleft (gap)

cleft palate

birth defect resulting from a failure of the two halves of the hard palate to completely come together and fuse at the midline, thus leaving a gap between the nasal and oral cavities

cochlea

snail-shaped, fluid-filled structure responsible for converting sound vibrations into electrical signals that the brain can interpret as sound

color blindness

difficulty distinguishing certain colors, often red and green or blue and yellow

concussion

a type of traumatic brain injury (TBI) that occurs when the brain experiences a sudden and forceful movement within the skull

conductive hearing loss

occurs when something in the external or middle ear is obstructing the transmission of sound

cone

photoreceptor that is primarily responsible for color vision and visual acuity

congenital ear pit

small depression near the external ear present at birth

congenital ear tag

small piece of extra tissue present at birth

conjunctiva

thin, transparent membrane covering the front surface of the eye

conjunctivitis (also, pink eye)

inflammation of the conjunctiva

connective tissue disease

disorder affecting tissues such as skin, tendons, and cartilage

cornea

clear, dome-shaped front surface of the eye

corneal abrasion

scratch or injury to the cornea’s surface

corneal scar

tissue that forms after the healing of a deep eye injury

Cushing syndrome (also, hypercortisolism)

characterized by an excessive and prolonged exposure to high levels of the hormone cortisol

deviated septum

thin wall (nasal septum) that separates the two nasal passages is displaced or shifted to one side

diplopia

seeing two images of a single object

dry mouth

reduced saliva production

earwax impaction

a buildup of earwax (cerumen)

ectropion

outward turning of the lower eyelid

enlarged tonsils

swollen tonsil

epiglottis

a flexible piece of cartilage that covers the opening of the trachea during swallowing to prevent ingested material from entering the trachea

epiglottitis

inflammation of the epiglottis

epistaxis (also, nosebleed)

bleeding from the blood vessels within the nasal passages

erythroplakia

red patches on the oral mucosa

ethmoid bone

bone located between the eye sockets and forms part of the nasal cavity

eustachian tube

connects the middle ear to the back of the nose

exophthalmos

bulging or protruding eyeballs

external auditory canal

a tubelike structure that connects the pinna to the eardrum

external ear

composed of pinna (auricle) and external auditory canal

extraocular movement

movement of the eye that is controlled by a group of muscles surrounding each eye

eyebrow

the hair-covered ridge above the eye that helps protect the eye from sweat and direct sunlight

eyelashes

short hairs along the eyelid edge that helps prevent debris from entering the eye

eyelid

the movable fold of skin and muscle that covers and protects the front of the eye

facial drooping

an asymmetrical facial expression that occurs due to damage of the nerve

flash

brief, flickering light or sensation that occurs in the visual field

floater

small, semitransparent spot or shape that appears to “float” in the field of vision

foul taste

bad taste in the mouth

frontal bone

bone that forms the forehead and the upper portion of the eye sockets

gastroesophageal reflux disease (GERD)

condition resulting from chronic acid reflux

glaucoma

a group of eye disorders characterized by increased intraocular pressure that damages the optic nerve, causing gradual peripheral vision loss and potential blindness

gum disease

infection of the tissues that hold the teeth in place

gustation

taste

halitosis

persistent foul-smelling or bad breath

halo

glowing circle or ring around a light source

headache

a common and uncomfortable sensation of pain or discomfort in the head or upper neck area

hordeolum (also, stye)

painful, localized infection or inflammation of an eyelid gland

hyperopia (also, farsightedness)

distant objects are clearer than close ones

inner ear

composed of the cochlea and the vestibular system

inner ear trauma

trauma to the head or ears that results in inner ear damage

iris

colored part of the eye

labyrinthitis

inflammation of the inner ear

lacrimal duct

drains tears from the eye’s surface to the nasal cavity

lacrimal gland

produces tears that keep the eye moist

laryngitis

inflammation of the larynx (vocal cords)

larynx

tubular airway structure at the superior part of the trachea that connects the pharynx to the trachea and helps regulate the volume of air that enters and leaves the lungs; contains the vocal cords

lens

transparent, flexible structure located behind the iris

leukoplakia

thickened, white patches on the oral mucosa

levator scapulae

muscle located along the side of the neck

linear scleroderma

a line of scleroderma

macrotia

abnormally large ears compared to typical proportions

macula

small, central area of the retina responsible for central vision and color perception

macular degeneration

gradual and progressive damage to the macula

mandible

lower jaw bone

mastoid process

bony prominence behind the ear

maxilla

upper jaw bone

Ménière disease

disorder of the inner ear characterized by episodes of vertigo (spinning sensation), fluctuating hearing loss, tinnitus (ringing in the ears), and a feeling of fullness or pressure in the ear

microtia

a congenital condition where the external ear is underdeveloped or absent

miosis

abnormal constriction of the pupil

morphea

patches of scleroderma

mydriasis

pupil dilation

myopia (nearsightedness)

distant objects appear blurry while close objects are clear

myringitis

inflammation of the eardrum

myxedema

severe form of hypothyroidism that occurs when the thyroid gland does not produce enough thyroid hormones

nasal polyp

noncancerous growth that develops inside the nasal passages or sinuses

nasal septum

internal wall, composed of bone and cartilage, that divides the nose into left and right nostrils

night blindness

difficulty seeing in low-light conditions

nystagmus

an involuntary, rhythmic, back-and-forth movement of the eyes

occipital bone

bone that forms the back and base of the cranium

olfaction

smell

optic atrophy

degeneration of the optic nerve fibers

optic disc

the area where the optic nerve exits the retina

optic nerve

the bundle of nerve fibers that carries visual information from the retina to the brain for processing

orbit

bony socket that houses the eyeball and the muscles that move the eyeball

otitis externa (also, “swimmer’s ear”)

an infection or inflammation of the external ear canal, usually caused by water exposure or bacterial/fungal infections

otitis media (also, middle ear infection)

Eustachian tube becomes inflamed and the middle ear fills with fluid, causing ear pain and irritability

papilledema

swelling of the optic disc at the back of the eye due to increased intracranial pressure

paranasal sinuses

a group of air-filled spaces within the bones of the face and skull, located around the nose and above the eyes

parietal bones

bones that form the majority of the upper sides and the roof of the cranium

perforated eardrum

a hole or tear in the tympanic membrane

peripheral vision

ability to perceive objects, movement, and light outside the central area of focus

peritonsillar abscess

a collection of pus behind the tonsils that can cause severe sore throat, difficulty swallowing, and voice changes

persistent toothache

toothache that will not go away

pharyngitis

inflammation of the pharynx

pharynx

muscular tube that connects the nasal cavity and mouth to the voice box (larynx) and the esophagus (food pipe); also known as the throat

photophobia

sensitivity to light

presbycusis

sensorineural hearing loss that occurs with aging due to gradual nerve degeneration

presbyopia

age-related difficulty in focusing on close objects

pterion

point where the frontal, parietal, sphenoid, and temporal bones meet

pterygium

a growth of tissue on the conjunctiva that can extend onto the cornea

ptosis

drooping of the upper eyelid

pupil

black circular opening in the center of the iris

Raynaud phenomenon

a condition that causes pale or blue fingers with cold exposure

retina

innermost layer of the eye that contains photoreceptors (rods and cones)

rheumatic disease

condition that primarily affects the joints, muscles, and bones

rhinitis

inflammation of the nasal passages

Rinne test

clinical test that compares air conduction (AC) and bone conduction (BC) to assess whether hearing loss is due to conductive or sensorineural factors

rod

photoreceptor that is responsible for vision in low-light conditions and for detecting movement

Romberg test

clinical assessment used to assess balance

scalene muscles

muscles located on the side of the neck

sclera

white, tough outer covering of the eye

scleroderma (also, systemic sclerosis)

a chronic, autoimmune disorder that causes inflammation in the skin

sensorineural hearing loss

hearing loss caused by pathology of the inner ear, cranial nerve VIII, or auditory areas of the cerebral cortex

simple goiter (also, endemic goiter)

noncancerous enlargement of the thyroid gland that results in visible swelling of the neck

sinusitis

inflammation of the sinuses

sphenoid bone

bone that sits at the base of the skull

Stahl ear (also, “Spock ear”)

condition involves a pointed or elflike appearance of the upper part of the ear due to an extra fold

stapes (also, stirrup)

the smallest bone in the human body; transmits vibrations from the incus to the oval window of the cochlea

sternocleidomastoid

muscle that runs diagonally from the base of the skull behind the ear to the sternum and clavicle

strabismus

misalignment of the eyes causing one eye to turn inward, outward, upward, or downward while the other eye remains focused

sutures

fibrous joints that connect the bones of the skull

temporal bones

bones located on the sides and base of the skull

thyroid

a butterfly-shaped endocrine gland located in the front of the neck, just below the Adam’s apple (thyroid cartilage)

tinnitus

ringing, buzzing, or hissing sounds in the ears

tonsillar exudate

white or yellow patches on the tonsils

tooth decay

visible cavities or holes in the outer sruface of a tooth or enamel

tooth mobility

teeth feel loose or shift position

tooth sensitivity

sharp pain or discomfort when consuming hot, cold, sweet, or acidic foods and beverages

trapezius

large muscle that extends from the base of the skull down to the upper back

traumatic brain injury (TBI)

damage to the brain caused by a sudden, external force or trauma

turbinates

a bony structure covered in mucous membrane that protrudes into a nasal cavity and helps to humidify and filter the air

tympanic membrane retraction

the eardrum is pulled or retracted into the middle ear

tympanosclerosis

involves the formation of thickened or scarred areas on the eardrum due to repeated infections or inflammation

vertigo

sensation of spinning or dizziness

vestibular system

composed of the semicircular canals and the vestibule

visual acuity

measures a person’s ability to see details at a specific distance

visual field

area that an individual can see when their gaze is fixed straight ahead

visual reflex

automatic and involuntary response of the eyes and the body to visual stimuli

vitreous humor

a gel-like substance that fills the space within the eye

Weber test

clinical test used to determine whether hearing loss is present in one ear or if it is roughly equal in both ears

zygomatic bone

cheekbone