The plateau phase of the cardiac muscle action potential is due to:
Correct Answer: The calcium channels remaining open longer than the sodium channels
Description: In cardiac muscle the action potential is cause by opening of two types of channels: 1) Fast sodium channels 2) Slow calcium channels This second population of channels differs from the fast sodium channels in being slower to open and even more impoant, they remain open for several tenths of a second. During this time a large quantity of both calcium and sodium ions flows through these channels to the interior of the cardiac muscle fiber and this maintains a prolonged period of depolarization causing the plateau in the action potential.
Category:
Physiology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now