Flashcards in Special Sense Organs Deck (73)
rods/cones contain rhodopsin-a photopigment
rods = rhodopsin (need Vit A)
cones/rods responsible for color vision
cones = color vision
rods/cones used for dark adaptation
rods =dark ===> hint look at the letters = r and d
rods and cones are located in the
which are more abundant: rods or cones
the __ is the innermost layer of the eye
the __ is the nervous tissue of the eye
retina receives visual stimuli and send the info to the brain. Photoreceptor cells called __ and __ compose the visual receptors for the optic nerve of the retina
rods and cones
there are 4 different photopigments consisting of a protein called __ to which retinal is attached
opsin differs from pigment to pigment and cnfer specific light sensitive properties on each photopigment. Retinal produced from ___ is added to opsin to make?
vitamin A ==> retinal ==> retinal + opsin = rhodopsin
rods contain the photopigment
rods are numerous in the __ of the retina
what are the 3 different types of cones?
red, blue, green (RBG), each contains a different photopigment and is selectively sensitive to diff wavelengths.
cones are numerous in the _ of the retina
center of the retina, especially the fovea
during dark adaptation (dark vision) rhodopsin is synthesized in the rods. Severe vitamin A deficiency over many months causes
___ are the principal photoreceptors during daylight or in brightly lit areas
Rods are more/less abundant?
Rods are more/less sensitive (than cones)?
more or less acuity?
rods are more abundant, have higher sensitivity and less visual acuity
the crystal clear dome that covers the front of the eye is called
the majority of the focusing in the eye is done by the:
lens or the cornea?
cornea! 70% of bending/refracting of light rays occurs here
does the shape of the cornea change
no (with the exception of small changes over lifetime)
the crystalline ___ finishes the focusing of light after the cornea does the majority.
can the lens change shape
yes. it can fine tune vision due to this ability.
when the __ becomes cloudy = cataract
the opening in the middle of the iris
part of the eye that gives it color
this part of the eye acts like a shutter allowing more or less light into the eye
this is a thin layer of nerve tissue that senses light. specialized cells called rods and cones convert light energy into nerve signals that travel thru the optic nerve to the brain.
the retina is analogous to film on a camera
this is the center of the retina that receives the focus of the object. nerve cells are more densely packed here especially the CONES so images focused here can be seen in greater detail
the is the nerve that runs from the eyeball to the brain. carries info from the retina to the brain for interpretation
the eyeball itself is divided into 2 segments each filled with fluid. the anterior segment has how many chambers
2 = anterior and posterior. anterior is between the cornea and the iris and the posterior between iris and lens
the anterior chamber (both posterior and anterior) is filed with aqueous or vitreous humor?
anterior is Aqueous humor = watery (think your eyes water/tear in the front, and A is for anterior and aqueous
the vitreous humor is thick and gelatinous and located in the __ of the eye
sound waves strike the __ and cause it to vibrate
vibration of the tympanic membrane causes the oval/round__ to vibrate next
the oval window vibration causes the ____ in the bony labyrinth of the cochlea and the ___ in the membranous labyrinth to move.
perilymph = bony labyrinth
endolymph - membranous labyrinth
the movement of the endolymph causes the ___ to vibrate
the movement of the basilar membrane stimulates hair cells on the __ to transmit nerve impulses along the cranial nerve ==> auditory complex = interpreted as sound
organ of Corti
external ear made up of
auricle (directs sound waves) aka pinna
external auditory canal (meatus) = contains hair and cerumen (brown earwax), resonates sound
the middle ear aka typmpanic cavity is located in the __ bone and is filled with
temporal bone and filled with air
middle ear is made of
auditory tube = equalizes pressure
and ossicles (malleus incus stapes) transmit sound to oval window and create a 22 fold amplification of sound from the tympanic membrane to oval window
inner ear is formed by
a membranous labyrinth within a bony labyrinth
the inner ear is mainly responsible for __ and __.
sound detection and balance.
1. vestibular system, is dedicated to__
2. The cochlea, dedicated to ___; converting sound pressure patterns from the outer ear into electrochemical impulses which are passed on to the brain via the auditory nerve.
The inner ear is innervated by the ___cranial nerve in all vertebrates
VIII = vestibulocochlear nerve
The bony labyrinth, or osseous labyrinth, is the network of passages with bony walls lined with periosteum. The membranous labyrinth runs inside of the bony labyrinth. There is a layer of ____ fluid between them
The vestibular system is the region of the inner ear where the semicircular canals converge, close to the cochlea. The vestibular system works with the___system to keep objects in focus when the head is moving
the vestibule is made of __ and is associated with sense of balance
saccule and utricle
the semicircular canals are concerned with
the cochlea contains 2 membranes: the _ and _
vestibular and basilar.
the receptors for hearing are located in the _ and are called
organ of Corti
the basic functional unit of hearing is the
cochlea = transforms fluid vibrations from sound waves (mechanical energy) into nerve impulses (electrical energy)
the tympanic membrane and tympanic cavity, semicircular canals, vestibule, and eustachean tube opening are located in the _ of the ear
the cochlea is located in which part of the ear
inner (along with the vestibular and cochlear nerve (CN 8)
your patient just came back from an ophthalmology appointment where she received tropicamide to induce mydriasis. how will it affect her dental appointment
patient will be extra sensitive to the overhead dental light
constriction of the pupil
PROLONGED abnormal dilation of the pupil induced by a drug or disease and causes the eye to become extra sensitive to light
nearsightedness = eye can focus on very near objects.
in ___ myopia/hyperopia:
the eye is too long for the refractive power of the lens, and far objects are focused at a point IN FRONT OF THE RETINA.
myopia is caused by either
1. eye is too __ compared to normal
2. or cornea is __than normal
to remember: think near sighted, the object is right in front (near) the retina and I cant see far bc im in a cave and the corn is steep
to treat myopia what kind of lens would you wear: convex/concave/cylindric
myopia = cornea steep/eye too long/concave lens/far objects are focused in front of the retina
to remember = think near sightedness, so the object focuses more near the object. in far sightedness the object is focused far away from the eye (behind the retina)
in ___ myopia/hyperopia:
the light focuses BEHIND THE RETINA
1. the cornea is __ or the eye is __
cornea is flatter, or eye is shorter (remember in myopia the cornea was steeper or eye was longer)
farsighted pp usually have trouble seeing up close but may also have difficulty seeing far away as well. to treat hyperopia what kind of lens?
___ occurs when the curvature of the lens is not uniform.
astigmatism is corrected with which lens
1. myopia lens
2. hyperopia lens
3. astigmatism lens
mnemonic for myopia and hyperopia
myopia is the "short" word = near sighted
hyperopia is the "long" word = far sighted
My cave" (Myopia - Concave)
eye cant focus sharply on nearby objects - bc of loss of elasticity of the lens with advanced aging.
presbyopia corrected with
bifocals = to remember just look at the word: presByopia = bifocals - only one with a B
what are opsins
Opsins are a group of light-sensitive membrane-bound G protein-coupled receptors found in photoreceptor cells of the retina. opsins are involved in vision, mediating the conversion of a photon of light into an electrochemical signal, the first step in the visual transduction cascade. Another opsin found in the mammalian retina, melanopsin, is involved in circadian rhythms and pupillary reflex but not in image-forming.
what is visual purple
another name for Rhodopsin