Question 1
Acetylcholine slows the heart rate by just
◦ increasing the permeability to Ca
2+.
◦ increasing the permeability to K
+.
◦ increasing ion influx, thus increasing the rate of depolarization.
◦ decreasing the permeability to Ca
2+.
◦ increasing the permeability to K
+ and decreasing the permeability to Ca
2+.
Question 2
Sympathetic stimulation increases the heart rate by
◦ increasing the permeability to K
+ and decreasing the permeability to Ca
2+.
◦ increasing ion influx, thus increasing the rate of depolarization.
◦ just decreasing the permeability to Ca
2+.
◦ just increasing the permeability to K
+.
◦ just increasing the permeability to Ca
2+.