The function of the atrioventricular node is to
a. excite the left and right atrium
b. control the heart rate
c. prevent the atria and ventricles from contracting simultaneously
d. repolarize the heart after systole
e. stimulate ventricular contractile cells directly
C
You might also like to view...
Suppressor T cells act to
A) suppress antigens. B) erase memory T cells. C) limit antigen proliferation. D) inhibit T and B cell activities. E) produce antibodies involved in autoimmunity.
Which of the following mechanisms produces the most ATP during cellular respiration?
A) oxidative phosphorylation B) oxidation reactions C) lactic acid production D) substrate-level phosphorylation
A retinal OFF-center bipolar cell:
A. depolarizes in response to a light in the center of its receptive field B. has metabotropic glutamate receptors that close Na+ channels C. depolarizes in response to a light in the periphery of its receptive field D. is hyperpolarized by horizontal cell input E. connects to ganglion cells but not horizontal cells
Which is the "kiss muscle" used for puckering the lips?
A. Orbicularis oculi B. Depressor anguli oris C. Depressor labii inferioris D. Procerus E. Orbicularis oris