Lab #8: Sensory Physiology Flashcards
How many sensory neurons does it take to take information to the brain?
3
Different areas of the brain perceive ____________ ____________ _________
specific sensory information
Where are sensory receptors located?
on the dendrite of ONLY the first sensory neuron (in a series of neurons)
What is the function of a sensory receptor?
captures sensory information (external stimulus)
How does a sensory receptor carry out its function?
takes sensory stimuli information (transduce) and converts it into an AP
What is it called when a sensory receptor takes sensory stimuli information and converts it into an AP?
transduce into an AP
Define modality
form of external stimulus
Each unique type of sensation is called…
a sensory modality
Each sensory neuron carries information for _____ modality
one
_______ is converted into an AP
modality
What type of receptor would be involved in light modality?
photoreceptors
Where are general/cutaneous receptors located?
What modalities do general/cutaneous receptors respond to?
location: near epithelial surfaces; all over body
respond to: touch, pressure, temperature
For general/cutaneous receptors, the receptor is _____ of the first sensory enruon
part
Where are special senses receptors located?
What modalities do special senses receptors respond to?
location: sensory organs, but only found in specific locations (ex. eye contains photoreceptors and nose contains olfactory receptors)
LES
- light/vision
- equilibrium
- sound/hearing
For special senses receptors, the receptor is _________ from the first sensory neuron
separate
All receptors ultimately _______ to a stimulus
adapt
(decrease in response to stimulus after some time: slowly/quickly)
What are tonic receptors?
Provide examples
- respond at constant rate as long as stimulus applied
- adapt slowly to stimuli (ex: pain)
What are phasic receptors?
Provide examples
- respond with burst of activity, but quickly reduce response to constant stimulation
- adapt quickly to stimulu (ex: smell, touch)
What is a generator potential (GP)
are sensory receptors equivalent to an EPSP
- are produced in response to adequate stimuli -> if threshold reached -> AP generated
Why, in terms of receptive fields, do the different areas have different two-point thresholds?
each receptive field in the skin varies depending on the density of receptors in that region
Which of the areas that we tested had the largest receptive fields?
Which of the areas that we tested had the smallest receptive fields?
largest: upper arm
smallest: fingertip
Why is it difficult for the brain to discern multiple stimuli coming from the same receptive field?
all stimulus coming from a given receptive field goes to the same location in the brain
Which of the areas that you tested would have the largest brain region dedicated to it? Explain
fingers because they have a smaller receptive field, meaning there are more neuronal pathways = more brain area required
Larger receptive fields have…
Smaller receptive fields have…
lower localization ability
finer sense of tactile discrimination
Define conduction deafness
when the conduction of the sound wave through the outer/middle ear is impaired
Define neural deafness
when ear structures in the inner ear, cochlea, or cochlear nerve to the brain regions responsible for hearing are compromised
In the webster test, where would an individual with normal ears hear the tone louder? Why?
Where would an individual with conduction deafness hear the tone louder? Why?
Where would an individual with neural deafness hear the tone? Why?
normal ear: tone is equally loud, so sound will be localized as coming from the midline
conduction deafness: louder in deaf ear because in normal ear sound is partially masked by environmental noise
neural deafness: louder in normal ear because neural activity is essential for hearing
In the Rinne test, with a person who has normal ears, where is the sound perceived longer? air or bone
With a person who has conduction deafness, where is the sound perceived longer?
With a person who has neural deafness, where is the sound percieved longer?
normal ears: longer by air bc the threshold for air conduction is lower than bone
conduction deafness: longer by bone because something is affecting the conduction of soundwaves
neural deafness: longer by air
One patient (#1) takes a visual acuity test using a snellen chart. Their results read: 10/100
Another patient (#2) takes the same test and their results read: 30/20
Who has better vision? Explain why and be detailed.
patient #2 has better vision
patient #1 has poor vision because the top number refers to the distance (ft) that they are standing from the chart to read a specific line. the bottom number indicates how far the majority of people can read the specific line. patient #1 can only read the specified line from 10 feet away, while other people are able to read the line from 100 feet away.
patient #2 has the best vision because he can read the specified line from 30 feet away, while the majority of people can only read from 20 feet away.
