Asked by Jurgen Brecani on Jun 17, 2024
Verified
Which of the following would result from a reduced function of the Na+ channels in the SA node?
A) Depolarization would be delayed.
B) The heart rate would decrease.
C) Repolarization would not occur.
D) The plateau phase would be shorter.
E) Depolarization would be delayed, and the heart rate would decrease.
Na+ Channels
Specialized proteins in cell membranes that allow sodium ions to enter or leave a cell, playing a key role in generating electrical signals.
SA Node
The sinoatrial node, a group of cells located in the right atrium of the heart that initiates the electrical impulses governing the heart rate, often considered the heart's natural pacemaker.
Depolarization
The process by which the resting potential of a cell membrane becomes less negative, leading to the initiation of an action potential.
- Analyze the effects of ion channel function on heart rate and rhythm.
Verified Answer
PH
Pauwy HilwaJun 20, 2024
Final Answer :
E
Explanation :
The Na+ channels, while not a standard designation for ion channels, seem to refer to sodium channels involved in the pacemaker potential and action potential initiation in the SA node. Reduced function of these channels would delay the depolarization process, leading to a slower initiation of action potentials. This, in turn, would decrease the heart rate, as the SA node sets the pace for the heart's rhythmic contractions.
Learning Objectives
- Analyze the effects of ion channel function on heart rate and rhythm.