Question

'Bundle of His' is a part of which one of the following organs in humans?
(a) Brain
(b) Heart
(c) Kidney
(d) Pancreas

Answer 1

Hint: A network of muscle fibers, found in the walls of ventricles is 'Bundle of His'. It transmits the electrical impulses from the AV node to the point of the apex via bundle branches. They are responsible for the contraction of the cardiac muscles.

Complete answer:
‘Bundle of His’ is a collection of heart muscles for the electrical conduction from the right ventricle of the heart to regulate the heartbeat in the human body. The purkinje fibers then provide the electrical impulses to the ventricles after they are released from the bundle branches. This leads to the contraction of the cardiac muscles in the ventricles at a regular interval.
- The bundle of His is made up of wide those muscle fibers that are fast- conducting and carry the cardiac impulse into the upper part of the fibrous ventricles via the insulating annulus fibrosus. This leads to the formation of the left and the right bundle branch.
- The nerve impulse takes just 0.03 - 0.04seconds to travel from the bundle of his to the ventricle of the heart.
- The action potential is produced spontaneously at a rate of 30 - 40 beats per minute by the left and right branches of this bundle along with the Purkinje fibers. These cells may act as pacemakers if both the SA node and the AV node fails to work.
- If the bundle of His got damaged then it can lead to heart blocks ranging from AV conduction delays to a complete disconnect in the electrical conduction between the atria and ventricles.
- If the bundle of His stops working then the rate and rhythm of the heartbeat is not affected, but the impulse is slowed.
So, the correct answer is ‘Heart’.

Note: Bundle of His was discovered in 1893, by Swiss Cardiologist and anatomist Wilhelm His JrIt is named after him while in 1839 Jan Evangelista Purkyne discovered the Purkinje fibers and is named after him.