Question

There can be more than one answer.

33. Factors that contribute to the constantly depolarizing pacemaker potential include

A. closing of the Funny type Na+ channels early during the pacemaker potential

B. a brief opening of the T-type Ca2+ channels late during the pacemaker potential

C. opening of the L-Type Ca2+ channels late during the pacemaker potential

D. continued closing of K+ channels during the pacemaker potential

E. none of the above

Answer 1

The correct option is C.

• During the pacemaker potential, L type calcium channels open in the latter part.
• Option A is incorrect because, funny type sodium channels are open and not closed, early during the pacemaker potential.
• Option B is incorrect because brief opening of T type calcium channels occurs in the early phase, and not the late phase of pacemaker potential.
• Option D is incorrect because potassium channels open in the late phase of pacemaker potential, they are not continuously closed