P lab: Special Senses-Graf Flashcards
A father comes to the pediatrician’s office with his three-year old daughter, who is a new patient. As part of the initial examination, the pediatrician performs tests on the child’s visual system. Which of the following visual tests is designed specifically for use with small children?
Lea test
As part of a standard examination, a patient is tested for astigmatism. The test shows that the patient has astigmatism in both eyes. This result indicates a defect in which structure of the eyes?
cornea
Which of the following is most directly tested using a perimeter mapping apparatus?
visual field
Distinguish the Rinne and Weber tests.
Rinne tests both air and bone conduction of each ear
Weber test ONLY bone conduction of both ears at the same time
Which pathway mediates horizontal conjugate gaze?
Abducens interneuron pathway
On the Snellen Chart, one period (letter element + interspace) subtends which angle at the designated viewing distance?
2 minutes of arc
Red-green color blindness affects
mainly males due to the defect gene being located ont he X-chromosome
Cold water irrigation of the left ear will elicit
nystagmus to the right
During a head movement with eyes open,
????
Visual-vestibular interaction stimulation elicits
?????
The main role of ascending vestibular pathways is
vestibulo-ocular reflex and cortical ?????
Snellen chart
Snellen chart has sloan letters. They work on the spatial frequency detection of the visual system. One letter element 1 minute of arc. Period- 2 minutes of arc.
Sloan letters, -above
Landolt C
good for those who can’t read and writing
Lea test
visual acuity for kids, pictorial
Amsler grid
- for macular degeneration
- scotoma or wavy lines
- the lines get wavy at the beginning of macular degeneration
Ishihara test
color test
astigmatism wheel
To test for astigmatism at home click here or take a look at the image below with your glasses or contact lenses on. Covering one eye, sit 14 inches from your computer and observe the lines. Check with the other eye. If the lines are sharp and dark, you do not have astigmatism
perimeter mapping test
Visual field testing can be performed clinically by keeping the subject’s gaze fixed while presenting objects at various places within their visual field. Simple manual equipment can be used such as in the tangent screen test or the Amsler grid. When dedicated machinery is used it is called a perimeter.
Define “diopter”.
1/focal length
Conduction deafness
impairment of the transmission of sound coming through the ear going to the sensory cells
Tinnitus
ringing or clicking sound in the ears in the absence of auditory stimuli
Presbycusis
the most common type of Sensorineural Hearing Loss caused by the natural aging of the auditory system; loss of high frequencies
EG
no tympanic membrane → can still hear with bone conduction
otosclerosis
→ again can hear with bone conduction.
otosclerosis
-affects the ossicles thus affecting air conduction
→ again can still hear with bone conduction.
Otoacoustic emission test
OAE test is used to find out how well your inner ear, or cochlea, works
Otoacoustic emissions (OAEs) are sounds of cochlear origin, which can be recorded by a microphone fitted into the ear canal. They are caused by the motion of the cochlea's sensory hair cells as they energetically respond to auditory stimulation. OAEs are sounds given off by the inner ear when responding to a sound. There are hair cells in the inner ear that respond to sound by vibrating. The vibration produces a very quiet sound that echoes back into the middle ear. This sound is the OAE that is measured.
Which type of hearing loss would be mimicked by plugging one ear with cotton?
Conductive hearing loss
How would plugging one ear affect the results of the Rinne test?
Air conduction will be inhibited. Bone conduction will improve (be higher) in the ear that is plugged.
Damage to which components of the ear might contribute to conduction deafness?
impacted earwax, perforated eardrum, osteosclerosis of the ossicles
Damage to which components of the ear might contribute to sensorineural deafness?
damage to the hair cells, cochlear nerves
Damage to which CNS sites might result in sensorineural deafness?
Damage to the neural structures at any point from the cochlear hair cells to the auditory cortical cells
Cochlear nucleus.
Unilateral if you cut nerve or cochlear nucleus
How would plugging one ear affect the results of the Weber test?
In an affected patient, if the defective ear hears the Weber tuning fork louder(the plugged ear), the finding indicates a conductive hearing loss in the defective ear. In an affected patient, if the normal ear hears the tuning fork sound better, there is sensorineural hearing loss on the other (defective) ear.
visual perimeter
A perimetry test (visual field test) measures all areas of your eyesight, including your side, or peripheral, vision.
visual acuity
A perimetry test (visual field test) measures all areas of your eyesight, including your side, or peripheral, vision.
optic disc
the raised disk on the retina at the point of entry of the optic nerve, lacking visual receptors and so creating a blind spot.
astigmatism
It occurs when the cornea (the clear front cover of the eye) is irregularly shaped or sometimes because of the curvature of the lens inside the eye.
glaucoma
Glaucoma is a group of eye conditions that damage the optic nerve, the health of which is vital for good vision. This damage is often caused by an abnormally high pressure in your eye.
macular degeneration, (usually in old age)
Macular Degeneration is caused by the deterioration of the central portion of the retina, the inside back layer of the eye that records the images we see and sends them via the optic nerve from the eye to the brain.
myopia
nearsightedness;
hyperopia, farsightedness (HOW TO CORRECT);
achromatopsia,
Achromatopsia is a condition characterized by a partial or total absence of color vision.
protanopia
(no red- long wavelength waves) people affected by protan color blindness are less sensitive to red light
Deuteranopia,
(no green) (the second type of red-green color blindness) is related to sensitiveness on green light.
protanomaly, The different anomalous conditions are protanomaly, which is a reduced sensitivity to red light
deuteranomaly, which is a reduced sensitivity to green light tritanopia Actually the wording blue-yellow color blindness is misleading. People affected by tritan color blindness confuse blue with green and yellow with violet
tritanomaly
This is an alleviated form of blue-yellow color blindness, where the S-cones are present but do have some kind of mutation.
