Once an SA nodal cell reaches threshold, the depolarization phase occurs during which
A. potassium moves out through fast voltage-gated channels.
B. potassium comes in through fast voltage-gated channels.
C. calcium comes in through fast voltage-gated channels.
D. calcium moves out through slow voltage-gated channels.
E. sodium moves out through slow voltage-gated channels.
Answer: C
You might also like to view...
In most tissues, glucose, a water-soluble substance, crosses capillary walls through
a. water-filled pores b. endothelial cells c. sinusoids d. a and b e. a and c
An unknown molecule was detected in a tissue sample. The molecule is composed of carbon, hydrogen, and oxygen; appears to be a branching polymer; and is hydrophilic. This molecule is most likely a ________.
A. nucleic acid B. protein C. carbohydrate D. lipid
Terry suffers from dissociation of memories from their emotional content as the result of an automobile accident. What system of the brain is probably damaged?
A) the prefrontal lobe B) the general interpretive area C) the limbic system D) the thalamus E) the putamen
Oppositely charged ions in solution are prevented from combining by
A) heat capacity of water. B) hydration spheres. C) water's nonpolar nature. D) free radicals. E) hydrogen bonding.