Anatomy & Physiology第 69 / 100 题
What is depolarization?
a.The relaxation of cardiac muscle as it returns to its resting state
b.The electrical discharge of cardiac cells that stimulates contraction
c.The flow of blood into the coronary arteries
d.The closing of the atrioventricular valves
解析
Depolarization is the rapid electrical change across the cell membrane that triggers mechanical contraction, and it produces the P wave in the atria and the QRS complex in the ventricles. Relaxation and electrical recovery are repolarization. Coronary filling and valve closure are mechanical events of the cardiac cycle, not the electrical activity the EKG records.
免费刷完整 100 道题库 — 无需注册。
同考点相关题目
- What is the inherent rate of the Purkinje fibers, and what does a rhythm at that rate look like?
- What is the correct order of the cardiac electrical conduction pathway?
- Why does the impulse pause briefly at the AV node, and how does that pause appear on the EKG?
- A student asks why an EKG can look normal in a patient whose heart is not pumping effectively. What is the best explanation?
- What is the correct path of blood through the heart, starting with deoxygenated blood returning from the body?
- Which valve separates the right atrium from the right ventricle?