bio 162 chapter 7

anterior chamber

between cornea and iris

cornea

The clear tissue that covers the front of the eye and focuses light on the retina

iris

The colored part of the eye and block excessive light from entering

pupil

opening connecting the anterior and posterior chambers. light passes through

posterior chamber

between iris and lens

lens

Focuses light onto the retina. made of gel-like protein

ciliary body

contains smooth muscle cells that regulate the shape of the lens by pulling on the suspensory ligaments

Vitreous humor (body)

this "jelly ball" helps maintain the spherical shape of the eye. accumulation of cellular debris due to inflammation, as well as partial liquefaction of the vitreous humor contribute to the "floaters" some people see as they grow older

retina

layer of cells that convert light energy to electric impulses which are transmitted to the brain by the optic nerve

choroid

the layer contains blood vessels that nourish the eye, and its dark color absorbs stray light

sclera

tough white outer covering of the eye

optic nerve

carries electrical impulses from the eye to the brain

blind spot

area of the retina that does not contain any light-receptive cells that send impulses to the brain

Superior rectus muscle

rotates the eye upward

superior oblique muscle

rotate the eye clockwise or counter clockwise when the head tilts to either side

inferior rectus msucle

rotates the eye downward

inferior oblique muscle

rotate the eye clockwise or counter-clockwise when the head tilts to either side.

lateral rectus muscle

rotate the eye laterally

medial rectus muscle

rotates the eye medially

lacrimal gland

produces tears

Pinna (auricle)

outer ear

external acoustic meatus

outer tunnel that transmits sound vibrations to the tympanic membrane

tympanic membrane

ear drum. sound vibrations travel through the external auditory canal strike this membrane and cause it to vibrate

middle ear

between the tympanic membrane and the cochlea

malleus

first ear bone. amplify vibrations of the tympanic membrane and transmit those vibrations to the membrane covering the oval window

incus

second ear bone. amplify vibrations of the tympanic membrane and transmit those vibrations to the membrane covering the oval window

stapes

third ear bone. amplify vibrations of the tympanic membrane and transmit those vibrations to the membrane covering the oval window

oval window

membrane-covered opening to the scala vestibuli

inner ear

contains the cochlea, vestibule, utricle, ampullae, and semicircular ducts

vestibule

houses the utricle and saccule

semicircular canals (ducts)

This fluid filled system of chambers helps convert movement of the head into electric impulses (action potentials) that are transmitted to the brain. These impulses create your sense of angular movement (spinning/turning) in all three axes (dimensions).

cochlea

snail-shaped structure contains the chambers and tissues that convert sounds to the electric impulses that are transmitted to the brain

cochlear duct

central chamber in the cochlea that contains the hearing apparatus

scala vestibull

sound vibrations enter the chamber via the oval window

scala tympani

sound vibrations in the scala vestibuli may enter this chamber before they exit via the round window

round window

membrane-covered opening transmits vibrations from the scala tympani of the inner ear

auditory tube

helps the air pressure in the middle of the ear the same as the air pressure outside the body

vestibulocochlear nerve

hearing and balance

five sense

visual, auditory, gustatory, olfactory, snd tactile sense

semicircular canals

fluid-filled channels in the temporal bone of the skull

hair cells

semicircular canal has sensory receptors

two vestibular sacs

associated with the semicircular canals called the utricle and the saccule

utricle and saccule

provide sensations of gravity and linear acceleration and a sense of equilibrium