20-20,000 Hertz range of human hearing

Transcription

1 20-20,000 Hertz range of human hearing accommodation automatic adjustment in focal length of the lens of the eye; changing the shape of the lens aqueous humor Watery fluid in the anterior chambers of the eye astigmatism A condition in which unequal curvatures in different parts of the lens (or cornea) of the eye lead to blurred vision auditory ossicles The three tiny bones serving as transmitters of vibrations and located within the middle ear: the malleus, incus, and stapes

2 cataract clouding of the natural lens of the eye cerumen Earwax ceruminous glands found only in the external ear canal, where their secretion combines with sebum and dead epidermal cells to form earwax, or cerumen. chemoreceptors detect molecules in solution that are smelled or tasted choroid The vascular middle tunic of the eye

3 ciliary body the part of the eye that connects the iris to the choroid. It consists of the ciliary muscle (for accommodation), a series of radial ciliary processes (from which the lens is suspended by ligaments), and the ciliary ring (which adjoins the choroid). cochlea cones conjunctiva Snail-shaped chamber of the bony labyrinth that houses the receptor for hearing (the organ of Corti) One of the two types of photoreceptor cells in the retina of the eye; provide for color vision Thin, protective mucous membrand lining the eyelids and covering the anterior surface of the eye itself convergence ability to turn the eyes inward toward the nose to ensure only a single image of close objects is seen

4 cornea Transparent anterior portion of the eyeball; part of the fibrous tunic dynamic equilibrium Information about head movement especially rotation; semicircular canals emmetropia normal vision extrinsic (external) eye muscles voluntary eye muscles fovea centralis area consisting of a small depression in the retina containing cones and where vision is most acute

5 glaucoma increased pressure in the eyeball due to obstruction of the outflow of aqueous humor gustation Taste hyperopia A condition in which visual images are routinely focused behind the retina; commonly known as farsightedness intrinsic eye muscles involuntary eye muscles; includes the iris and clilary body lacrimal glands gland above the eye; continually lubricates the eye with tears

6 mechanoreceptors myopia a sensory receptor that responds to mechanical disturbances; hearing and balance receptors A condition in which visual images are focused in front of rather than on the retina; nearsightedness optic chiasma location where the optic nerve fibers cross in the brain optic disc (blind spot) region of the retina where the optic nerve leaves the eye organ of Corti organ located in the cochlea; contains receptors (hair cells) that receive vibrations and generate nerve impulses for hearing

7 ossicles three tiny bones in the middle ear otolith One of the small calcified masses in the utricle and saccule of the inner ear oval window membrane that covers the opening between the middle ear and inner ear pharyngotympanic (auditory) tube photopsin runs downward to link the middle ear cavity with the throat, swallowing and yawning opens it to equalize pressure in middle ear visual pigment of cones; consists of same retinal found in rods and 3 different opsin proteins which respond to 3 different light wavelengths

8 photopupillary reflex Eyes suddenly exposed to bright light experience: photoreceptors light-sensitive cells in the retina- the rods and cones presbycusis age-related hearing loss presbyopia farsightedness caused by aging proprioceptors in muscles and joints it provides information on changes in physical position

9 pupil Opening in the center of the iris through which light enters the eye retina rhodopsin rods round window Neural tunic of the eyeball; contains photoreceptors (rods, cones) A visual pigment consisting of retinal and opsin. When rhodopsin absorbs light, the retinal changes shape and dissociates from the opsin, after which it is converted back to its original form. One of the two types of photosensitive cells in the retina; Function in dim light conditions. membrane-covered opening in the inner wall of the middle ear that compensates for changes in cochlear pressure

10 sclera White opaque portion of the fibrous tunic of the eyeball scleral venous sinus (canal of Schlemm) structure that is responsible for reabsorption of aqueous humor; blockage results in glaucoma semicircular canals three canals within the inner ear that contain specialized receptor cells that generate nerve impulses with body movement; dynamic equilibrium static equilibrium tarsal glands maintenance of balance when the head and body are motionless; utricle and saccule within saccule Glands associated with the edges of the eyelids that secrete oil; modified sebaceous glands

11 taste buds Sensory receptor organs that house gustatory cells, which respond to dissolved food chemicals thermoreceptors detect changes in temperature tympanic membrane (eardrum) cone shaped semitransparent membrane attached to malleus; ear drum vestibule Static equilibrium receptors housed here vestibulocochlear nerve cranial nerve VIII

12 vitreous humor The gel-like substance that reinforces the eyeball and prevents it from collapsing inward is the: