Chapter 10 Flashcards
anterior cavity
the front third of the eye that includes the structures in the front of the vitreous humor: the cornea, iris, ciliary body, and lens
malleus
a small bone in the middle ear which transmits vibrations of the eardrum to the incus
aqueous humor
the clear fluid filling the space in the front of the eyeball between the lens and the cornea
medial rectus
an adductor, functions along with the lateral rectus which abducts the eye
auditory tube
hollow structure that extends from the middle ear to the pharynx
optic disk
the raised disk on the retina at the point of entry of the optic nerve, lacking visual receptors and so creating a blind spot
auricle
the visible portion of the outer ear
optic nerve
each of the second pair of cranial nerves, transmitting impulses to the brain from the retina at the back of the eye
oval window
a connective tissue membrane located at the end of the end of the middle ear and the beginning of the inner ear
choroid coat
the pigmented vascular layer of the eyeball between the retina and the sclera
pharynx
the membrane-lined cavity behind the nose and mouth, connecting them to the esophagus
ciliary body
the part of the eye that connects the iris to the choroid - consists of the ciliary muscle, a series of radical ciliary processes, and the ciliary ring
cochlea
the spiral cavity of the inner ear containing the organ of Corti, which produces nerve impulses in response to sound vibrations
cochlear duct
an endolymph-filled cavity located between the scala vestibuli and the scala tympani in the cochlea which is part of the inner ear along with the vestibular apparatus
pupil
the round opening in the center of the iris
cones
a type of photoreceptor cell in the retina - gives us color vision
retina
the light-sensitive layers of nerve tissues at the back of the eye that receive images and sends them as electric signals through the optic nerve to the brain
cornea
the transparent part of the eye that covers the iris and pupil and allows light to enter inside
rods
a type of photoreceptor cell in the retina - sensitive to light levels and help give us good vision in low light
round window
one of two opening in the middle ear at the level of the cochlea allowing communication between the mestoympanum of the middle and inner ear
external auditory meatus
passageway that leads from the outside of the head to the tympanic membrane, or eardrum membrane, of each ear
sclera
the white layer of the eye that covers most of the outside of the eyeball
fovea centralis
a small depression within the neurosensory retina where visual acuity is the highest
semicircular canals
three tiny, fluid-filled tubes in our inner ear that help you keep your balance
stapes
the innermost of the chain of three ossicles in the middle ear of a mammal having the form of a stirrup, a base occupying the oval window, and a head connected with the incus
incus
the middle bone of a chain of three small bones in the ear of a mammal
superior oblique
spindle-shaped muscle belonging to the extraocular group of muscles
inferior oblique
a thin, narrow muscle of the eye
superior rectus
elevates the eye, causing the cornea to move superiorly
inferior rectus
one of the seven extraocular muscles and is primarily responsible for depressing the eye (downgaze)
suspensory ligaments
a ligament or fibrous membrane suspending an organ or part
iris
the colored tissue at the front of the eye that contains the pupil in the center
tympanic cavity
separates the outer ear from the middle ear
lateral rectus
an abductor, moves the eye laterally and side to side along with the medial rectus, which is an adductor
tympanic membrane
(eardrum) sound waves cause it to vibrate, vibrations are then transferred to the tiny bones in the middle ear, which then transfer the vibrating signals to the inner ear
lens
a clear disk that focuses light - clear, curved structure at the front of the eye
vestibulocochlear nerve
a nerve that is responsible for the sense of hearing and that is also pertinent to the senses of balance and body position
What is the purpose/function of the ciliary muscle?
It produces the fluid in the eye called aqueous humor. It also contains the ciliary muscle, which changes the shape of the lens when your eyes focus on a near object. This process is called accommodation.
Where are the auditory ossicles located, what is the name of each?
They are found within the petrous part of the temporal bone - their names are malleus, incus, and stapes
Upon which structure of the eye can a cataract form?
On the lens.
List the structures and fluids through which light passes as it enters and travels through the eye.
The cornea, the aqueous humor, the pupil, the lens, the vitreous humor, and finally the photoreceptors of the retina.
What color light are the receptors within the retina most sensitive?
A yellowish-green color.
Describe sensory adaptation.
It refers to the way our senses adjust to different stimuli.
Describe referred pain.
Pain perceived at a location other than the site of the painful stimulus/origin.
What is the reason for the blind spot?
The optic nerve passes through the retina, where there are no photoreceptors there to detect light.
Rods and cones are located within what structure of the eye?
They are located within the retina.
What does it mean to have 20/20 vision; 20/200; 20/10?
20/20 vision means that you can see an object clearly from 20 feet away the same way a normal person can. 20/200 vision means that what others can normally see at 200 feet clearly, you can only see from 20 feet away. 20/10 vision means that what others can normally see clearly from 20 feet away, you have to be 10 feet away from to see clearly.
