Lab 1, 2 And 3 Flashcards
What factors produce RMP?
Na+ K+ ATPase pump
Higher preponderance of K+ nongated
Movement of K out of cell w/ concentration gradient
Big organic ions cannot leave cell
What is RMP
Difference in charge across a cell membrane when a cell is not stimulated
-70mV
How do ion channel proteins function to establish RMP?
Non gated channels allow ions to pass down its concentration gradient
How does the Na+ K+ ATPase pump establish RMP
Uses 1 ATP to produce 3 Na+ out and 2 K + in
What’s a graded potential and what is initially required to produce it
Change in MP usually small deviation from -70
A stimulus
Where do graded potentials occur on a neuron
Dendrites and cell bodies
What would you call generator potential produced on receptors on the skin ?
On inner ear?
At neuronal synapse?
Post synaptic membrane ?
Skin - generator potential
Inner ear - receptor potential
What specific electrical events occur during the production of a graded potential
Opening of gated channels of ions that change RMP
Any except voltage
Depolarization
Hyperpolarization
How is threshold reached at axon hillock
Influx of Na+ fast
In addition to skin which brain structure has thermoreceptors
Hypothalamus
Where in the cerebral cortex is sensory info interpreted ?
Post central gyrus
Sweat is produced what are the effectors and nt released?
Effectors sympathetic ns > ach
If you press the outer corner of your right eye while looking to the left you will see a dark circle surrounded by light near the ridge of your nose, why?
Caused by stimulation of the photoreceptors
This shows that the photoreceptors of the retina may be stimulated mechanically rather than via light, because a light receptor was stimulated
Are there more cold receptors or hot in the body ?
More cold receptors
More detectable in the square test than hot
What instrument was used for the two point discrimination test?
Aesthesiometer
Where on yr body is the two point discrimination greatest ? ie closest together ? Which were farthest apart
Or have more touch receptors
Spatial discrimination
On the finger tip
On the back
When a stimulus occurs on a subject when there eyes are closed and they try to pin point the location
In areas where there are more receptors what would happen
Where inter brain is this stimulus perceived
The localization of the stimulus Is more accurate
Post central gyrus
On the snellen eye chart if you are standing 20 ft away and able to read the letters designated to be read at 20 feet you have
20 / 20 vision
if you can only read the letters designated to be read at 200 feet at 20 (6m) feet then you have
20/200 vision
If astigmatism is present what does the astigmatism chart look like
Some of the spokes will appear sharp and dark while others blurred and lighter
If there is astigmatism and the chart is viewed as if there was one present , what can we deduce about focus of the image
Comes to focus infront of or behind the retina
What causes astigmatism ?
How can you tell if it has been corrected with glasses
The cornea is misshapen
And so the light doesn’t focus correctly on the retina
What does ishihara color plates test
Colourblindness / Deficiencies in color receptors (cones)!
3 cone types which contain diff photoreceptor pigment R,B,G
What is convergence
Medial movement of eyes which helps to maintain partial overlap of the visual field of each eye
