Which one of the following act as a PACEMAKER in heart:
Correct answer: D. Sinoatrial node
- A. Bundle of His
- B. Atrioventricular node
- C. Atrioventricular bundles of fibers
- D. Sinoatrial node
Explanation
Electrical impulses from the heart muscle cause your heart to beat (contract). This electrical signal begins in the sinoatrial (SA) node, located at the top of the heart's upper-right chamber (the right atrium). The SA node is known as the heart's "natural pacemaker. The bundle of His is a collection of heart muscle cells specialized for electrical conduction that transmits the electrical impulses from the AV node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the bundle branches. The atrioventricular node or AV node is a part of the electrical conduction system of the heart that coordinates the top of the heart. It electrically connects the atria and ventricles.
Last updated
About Circulation
The circulatory system covers the chambers, valves and conducting pathway of the human heart, along with the cardiac cycle and control of heartbeat. It compares arteries, veins and capillaries by structure and function, and explains how the lymphatic system returns tissue fluid, transports absorbed fats and supports immunity.
Practise Circulation
695 free Circulation MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Biology questions like this
Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
1% of the absorbed water is used by plants in its activities during:
75% osmotic pressure of blood is maintained by:
A bottle filled with previously moistened mustard seeds and water was screw-capped tightly and kept in a corner. It blew up suddenly after about half an hour. The phenomenon involved is
A column of water within xylem vessels of tall trees does not break under its weight because of:
A destarched leaf on a potted plant was covered with Black (A) Transparent (B) strips of paper as shown in figure. After 6 hours of exposure to sunlight the leaf was removed from the plant and tested for starch. Which are the following will be the correct observation?