In light adaptation,
a. phototransduction does not occur in the retinal regions outside of the fovea
b. rhodopsin levels decrease in rods
c. the iris' circular muscle relaxes
d. both a and b occur
e. both b and c occur
B
You might also like to view...
The axillary region is ________ to the pectoral region.
A. medial B. lateral C. proximal D. inferior E. distal
As a 20-year-old, Karl had his GFR measured by a urologist and found that it was 125 mL/minute. Now as Karl approaches 75 years old, he can expect that number to be cut
A. by a quarter. B. in half or more. C. by a fifth. D. by a third.
Draw graphs showing the effect on action potentials in a cell following effective doses of each of the listed neurotoxins. Assume that the cell is normally brought to threshold by an electrical stimulus applied to it, so that any abnormality is due to the toxin. Precise values for voltage and duration are not important, just a general trend in how the action potential may be different from normal.
1. puffer fish poison (blocks voltage -gated sodium channel activation) 2. tetraethylammonium (blocks voltage -gated potassium channels) 3. ouabain (blocks sodium-potassium pumps) 4. sea anemone toxin (blocks voltage -gated sodium channel inactivation)
While considered an organ of the gastrointestinal system, the ________ is not part of the gastrointestinal tract.
A. small intestine B. pharynx C. liver D. esophagus