Physio Exam 3 Chapter 10 Part 2 Flashcards
Vibrations by stapes and oval window produces pressure waves that displace______fluid within scala vestibuli
perilymph
Movements of perilymph travel to the base of _______ where they displace the round window
cochlea
As sound frequency increases, pressure waves of the perilymph are transmitted through the _____ membrane to the ______ membrane
vestibular, basilar
Displacement of basilar membrane is central to….
pitch discrimination
Waves in basilar membrane reach a peak at different regions depending upon pitch of sound.
Sounds of higher frequency cause maximum vibrations of _____membrane.
basilar
In the organ of corti, sensory hair cells (stereocilia) are located on what membrane?
basilar
When the cochlear duct is displaced, a shearing force is created between basilar membrane and tectorial membrane, moving and bending the what?
stereocilia
In the organ of corti, Ion channels open, depolarizing the hair cells, releasing _______ that stimulates a sensory neuron.
glutamate
Greater displacement of basilar membrane, bending of stereocilia; the greater the amount of ______released. Thus, increasing frequency of APs produced
NT
Sensory neurons in cranial nerve ______ synapse with neurons in medulla.
These neurons project to inferior colliculus of midbrain.
Neurons in this area project to thalamus.
Thalamus sends axons to ______cortex
VIII, auditory
Neurons in different regions of basilar membrane stimulate neurons in the corresponding areas of the_______.
Each area of cortex represents a different part of the basilar membrane and a different_____
auditory cortex, pitch
Transmission of sound waves through middle ear to oval window impaired.
Impairs all sound frequencies may require the use of
Hearing aids.
conductive deafness
Transmission of nerve impulses is impaired.
Impairs ability to hear some pitches more than others, may require
Cochlear implants.
sensorineural deafness
Eyes transduce energy in the electromagnetic spectrum into APs.
Only wavelengths of______nm constitute visible light
400-700
Neurons in the retina contribute fibers that are gathered together at the ______, where they exit at the_______
optic disc, optic nerve
Light that passes from a medium of one density into a medium of another density (bends), this is called?
refraction
What is the refractive index of air? refractive index of the cornea?
1.00, 1.38
Are images inverted on the retina?
yes!!!
Comparative density of the 2 media and the curvature of interface between the 2 media determines the….
refractive index
Image projected onto retina is the same in each eye? True or False
FALSE, reversed
Cornea and lens focus the right part of the visual field on ____half of retina.
Left half of visual field focus on ____ half of each retina
left, right
Ability of the eyes to keep the image focused on the retina as the distance between the eyes and object varies, this is called what?
accommodation
At distances >20 feet, relaxation places _____ on the suspensory ligament, this ____ the lens taut and the lens is least_____
tension, pulls, convex
At distances less than 20 feet, ciliary muscles____, reducing tension on the ___________, lens becomes more rounded and more ________
contract, suspensory ligament, convex
Nearsightedness or _______, the image brought to focus _____ the retina?
myopia, in front of
Farsightedness or ________, image brought to focus _______ the retina?
hyperopia, behind
Asymmetry of the cornea and/or lens.
Images of lines of circle appear blurred, this is called?
astigmatism
This part of the eye consists of single-cell-thick pigmented epithelium, layers of other neurons, and photoreceptor neurons (rods and cones)
retina
In the retina, neural layers are ______extensions of the brain. Neural layers face _______, toward incoming light.
forward, outward
Light must pass through several _____layers before striking the ____ and _____.
neural, rods, cones
Rods and cones synapse with other neurons.
Each rod and cone consists of ____ and _____segments
inner, outer
Outer segments of rods and cones contain hundreds of _______ discs with photopigment molecules.
flattened
APs are conducted outward or inward in the retina?
outward
Outer layers of neurons that contribute axons to optic nerve called….
ganglion cells
Neurons receive synaptic input from bipolar cells, which receive input from ____ and ______.
Horizontal cells synapse with photoreceptors and _____ cells.
Amacrine cells synapse with several ______ cells
rods, cones, bipolar cells, ganglion cells
Rods and cones are activated when light produces chemical change in…
rhodopsin
Rhodopsin dissociates into retinene and ______? 11-cis retinene dissociates from ______ when converted to all trans form
opsin, opsin
Gradual increase in photoreceptor sensitivity when entering a dark room.
Maximal sensitivity reached in 20 min is called….
dark adaptation
Increased pigment in cones produces slight dark adaptation in the 1st______, increased rhodopsin in rods produces greater increase in______
5 min, sensitivity
In regards to electrical activity of retinal cells, ganglion and amacrine cells are the only neurons that produce_______, whereas Rods/cones, bipolar and horizontal cells produces ______ and ________?
APs, EPSPs and IPSPs
In dark, photoreceptors release _________ that hyperpolarizes bipolar neurons
inhibitory NT
Light inhibits photoreceptors from releasing __________
inhibitory NT
In dark current, rods and cones contain many _____ channels that are open in the dark. This causes slight membrane _______ in the dark
Na+, depolarization
In the retinal cells, Na+ channles ________ in response to light? What is required to keep these Na+ channels open?
rapidly close, cGMP
In retinal cells, in the dark, opsin dissociates causing the alpha subunits of _______ to also dissociate.
This then binds to and activates phosphodiesterase, converting ______ to _______? Na+ channels close when _____ is converted to ______
G protein, cGMP, GMP, cGMP, GMP
Absorption of a ______photon of light can block Na entry, hyperpolarizing and release less __________
single, inhibiting NT
Cones are more sensitive than rods to light? true or false
false, LESS SENSITIVE
There are 3 types of cones, what are they?
blue, green, red
Each type of cone contains ______ associated with photopsins. Photopsin protein is _____ for each of the 3 cone pigments.
retiene, unique
Each of the 3 cones absorbs the same wavelength of light? true or false
false, DIFFERENT
Does the fovea only contain cones? Peripheral regions also only contain cones?
yes, no they also contain rods as well
Visual acuity is the greatest and sensitivity is the lowest when light falls onto the….
fovea
Quick, jerky movements.
Occur when eyes appear still.
Move image to different photoreceptors.
Ability of the eyes to jump from word to word as you read a line. This is what type of eye movement?
saccadic eye movement
Smooth pursuit movements:
Track moving objects.
Keep image focused on the fovea, this is what type of eye movement?
superior colliculus eye movement
In regards to visual fields:
Response produced by light in the center of visual fields–
Responses inhibited by light in the center, and stimulated by light in the surround—-
Part of visual field that affects activity of particular ganglion cell–
On-center fields,
Off-center fields, Receptive fields
