Special Senses: Eye and Ear Flashcards
accommodation
a process in which the lens flattens to adjust to something seen at a distance, or thickens for close vision
aqueous humor
the fluid produced by the capillaries of the ciliary body; nourishes the cornea, gives shape to the anterior eye, and maintains an optimum intraocular pressure
cones
sensory receptors which are concentrated in the central area of the retina and are responsible for color vision
conjunctiva
a protective, thin mucous membrane lining the eyelids
cornea
the portion of the sclera that covers the anterior section of the eye and is transparent
extraocular muscle
attach the eyeball to the orbit and, on impulse from the cranial nerves, move the eyes
fovea
an area within the macula that contains only cones and provides the sharpest image
iris
a smooth muscle that contacts and relaxes to moderate the amount of light that enters the eye; colored part of the eye except in albinism, in which they are reddish-pink
lacrimal gland
tear gland, provides a constant source of cleansing and lubrication for the eye
lacrimation
the process of producing tears
lens
an avascular structure made of protein and covered by an elastic capsule held in place by thin strands of muscle that make up the ciliary body
macula lutea
during daylight, the area of the retina on which the light rays focus
meibomian gland
sebaceous glands for the eyelashes, secrete oil to lubricate the eyelashes
optic disk
the area that allows a natural blind spot in our vision; where the optic nerve leaves the retina to travel to the brain; there are no light receptors there
orbit
the protective, bony socket encasing each of our eyes
palpebral fissure
the area where the upper and lower eyelids meet
pupil
the dark area in the center of the iris where the light continues its progress through to the lens
refraction
bending of light rays (happens through the cornea) so that they are projected properly onto receptor cells in the eye
retina
the inner layer of the eye which contains the sensory receptors for images carried by the light rays
rods
sensory receptors which appear throughout the retina and are responsible for vision in dim light
sclera
means hard; the white of the eye; the outermost lateral and posterior portion of the eye
uvea
the middle, highly vascular layer of the eye
vitreous humor
jellylike substance between the lens and the retina which holds the choroid membrane against the retina to ensure an adequate blood supply
auricle
aka pinna; the flesh-covered cartilage of the outer ear where sound waves are initially gathered
cerumen
earwax; protects the ear with its antiseptic property and its stickiness, trapping foreign debris and moving it out of the ear
cochlea
part of the outer, bony labyrinth which is an organ of hearing
crista ampullaris
the semicircular canals detect dynamic equilibrium, or a sense of sudden rotation, through the function of a structure called the ___
eustachian tube
aka auditory tube; a mucous membrane-lined connection between the ears and the throat that equalizes pressure within the middle ear
external auditory canal
gathered sound is funneled into the ___
external auditory meatus
the opening of the outer ear
incus
anvil (ossicle)
labyrinth
aka inner ear; the organ of receptors for hearing and balance
macula
a specialized patch of epithelium found in both the utricle and the saccule that provides information about the position of the head and a sense of acceleration and deceleration
malleus
hammer (ossicle)