Which of the following statements is true concerning the diastolic depolarization phase of a cell in the SA node?
A. The cell will not depolarize until it receives sympathetic stimulation.
B. The pacemaker potential is caused by Ca2+ entering the cell via L-type Ca2+ channels.
C. The pacemaker potential is slower in achieving threshold when acetylcholine is applied to the SA node cells.
D. During diastolic depolarization, there is a gradually increasing permeability to K+.
E. The slope of the diastolic depolarization is decreased when norepinephrine is applied to the SA node cells.
C
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Where is the flexor carpi radialis?
a) D b) E c) F d) G e) H
Assuming all other values are normal, calculate the net filtration pressure in a patient with a drop in capsular hydrostatic pressure to 8 mmHg.
A. 50 mm Hg out B. 30 mm Hg out C. 20 mm Hg out D. 40 mm Hg out E. 10 mm Hg out
The inability to produce a gag reflex could indicate a problem with the:
A) abducens nerve (VI) or trochlear nerve (IV). B) glossopharyngeal nerve (IX) or vagus nerve (X). C) facial nerve (VII) or trigeminal nerve (V). D) hypoglossal nerve (XII) or vestibulocochlear nerve (VIII).
Enzyme regulation by negative feedback involves
A. allosteric inhibition of an enzyme by a product of its metabolic pathway. B. allosteric facilitation of an enzyme by a substrate of its metabolic pathway. C. allosteric modification of a substrate by an enzyme of an alternate metabolic pathway. D. occupation of the active site of an enzyme so that it catalyzes less efficiently. E. enhancement of the active site by a negatively charged substrate.