Structures
What does bright light cause in the sphincter muscles? And what system of the ANS causes this?
The sphincter muscles in the iris surrounding the pupil to constrict making the pupil diameter smaller. This is caused by the parasympathetic division
The optic disc of the retina is called?
Blind spot
Normal color vision allows humans to see approximately how many different colors?
125 different colors
What causes sensory deafness?
Inner ear infections and exposure to prolonged excessively loud noises
What abnormalities can be detected by observing the retina with an ophthalmoscope?
Retinal attachment, floaters, birth vessels
In dim light, what does the sympathetic division of the ANS cause ?
Is activated and causes the dilator muscles in the iris to constrict making the pupil diameter larger
What happens when light hits the optic disc?
It cannot be perceived
Results from an inability to transmit sound to an intact and functioning inner ear
Conduction deafness
How is sensory deafness treated?
Cochlear implants
Why are vision and hearing tests given as part of a regular physical exam to young children before starting school?
To see if there are undiagnosed issues and to make sure the school will not misdiagnose learning disabilities
What would be considered a late indication of severe trauma or deterioration of brain stem tissue?
Absence of normal pupillary reflexes
What is binocular rivalry?
Phenomenon of visual perception in which perception alternates between diffferent images presented to each eye
What causes conduction deafness?
Anything that damages the outer or middle ear
What are the two differences for sound localization ?
1. The difference in the loudness of the sound reaching the two ears
2. The difference in the time of arrival of the sound at each ear
How is sound located? Why are we often inaccurate locating sound that originates in the midsagittal plane?
Arrival of time on each ear; the sound will arrive at both ears simultaneously and loudness will be the same on each ear
What is an ophthalmoscope and what does it do?
An instrument used clinically to view the posterior parts of the eyeball. This procedure allows practioners to view the retina and vitreous humor and most often requires pupil dilation drops
What do humans have that allow trichromatic color vision?
Cones
How can conduction deafness be treated ?
With hearing aids
Two people the same age may have different near point of vision measurements. How is this possible?
Your lens flexibility determinate with age and genetic differences
Webers test in someone with conductive hearing loss in one ear and another person with sensory loss in one ear
1. The results for conductive hearing loss you hear it louder on deaf ear than normal ear
2. The results for sensory is no sound at all because of no inner ear function
What structures are visible in the photograph of a retina through a ophthalmoscope?
Blind spot, central pit, branches of central artery
What colors are the cones?
Blue, green and red
What is sensory deafness?
Results from an inability to transduce or perceive sound
Is your visual awareness always an accurate representation of reality ?
No because of optimal allusion which is when you are noble to remember what you saw correctly
Rinnes test results
You can hear perfectly in both ears