Lab X - Questions Flashcards
How can we determine the minimal hearing threshold?
Increase the sound frequency until the test subject can hear the sound. The minimum hearing threshold is the first value (in Hz) at which the test subject can hear the sound.
Where in the body is the cutaneous sensation more accurate?
Palm, sole, lip, nose
What is the role of the outer ear canal?
Forwarding the sound waves towards middle ear ossicles.
What is the role of the ossicles?
Amplify and transmit signal to the inner ear (cochlea)
Describe Weber’s illusion?
Exact perception of certain objects is different on various skin regions due to the number of receptors located in the given area
What is the unit of sound?
Decibels dB= 10 log (I1/I2)
What is the measurement of sound?
Hz
What is the area on the retina, which has most visual acuity?
Macula luteum
Where in the brain is vision processed?
Visual cortex of the occipital lobe
What are the junctions of ossicles in middle ear?
Little bones located in the middle ear: eardrum to hammer, anvil, stirrup to cochlea
Why does the distribution of colors vary in field of vision?
Different distribution of colour sensitive receptors
What is binocular disparity?
There is a given distance between the 2 eyes so an object projects to the fovea centralism of the retina in both eyes but all other points that are in front or behind project to other locations of retina
Before reaching receptors cells, light refracts where?
The border of the cornea, the aqueous humour, the lens and the vitreous body
What is astigmatism?
Blurred vision due to inability of the optics of the eye to focus a point object into a sharp image on the retina
Describe the genetic background of red-green color blindness:
Inheritable recessive alleles of X sex chromosome. Recessive allele in woman causes problems on heterozygote form, in man it is hemizygote
Accommodation triad?
Adaptable curvature of the lens, eye movements, pupil function
Hearing range in human?
20 - 20,000 Hz
Why visual field isn’t circular?
Due to different structures on the face (e.g. nose, ears, etc.) might be covered by some parts of the theoretical field of vision
What are dB?
Scale measure for intensity of sound
Viewing angle?
Max angle at which a display can be viewed with acceptable visual performance
Measure of min viewing angle?
Arcminute / arcmin
Methods to find the blind spot?
Mariotte card + perimeter
What are thermoreceptors?
Non specialized sensory receptor that codes absolute and relative changes in temp
Define blind spot of retina
Where the optic nerve, retinal arteries, and veins leave the eye. No photosensitive receptors are here so we are unable to process an image projected here.
What is the biological explanation of the retinal after image?
Stimulation of ganglion cells of the retina do not cease immediately after ending of stimuli
Name 5 parts of the reflective arch
Receptor activation, signal travels toward CNS, signal is processed in CNS, information reaches receptor organ, effector organ executes order from CNS
Give an example of supporting roles
Defending of receptors, amplifying and modulating of the signal
