What is responsible for initiating the heartbeat?

Answer 1

There is a group of cells in the heart called the "pacemaker" that sends out a nerve shock to initiate a heartbeat. It also changes the pulse depending on certain external conditions to maintain homeostasis.

-Richard

Answer 2

A heartbeat is caused by an electrical impulse traveling through the heart. The heart's built-in electrical system controls the speed of its pumping. The electrical impulse originates in the sinus node which functions as the heart's natural pacemaker.

The sinus node is most often located in the top of the right atrium. The electrical signals travel through the heart tissue causing the atria and ventricles to contract and relax and the blood to be pumped to the body.

Answer 3

In the normal heartbeat, the automatic depolarization of cells in the sinoatrial (SA) node reaches a threshold level, causing a chain reaction throughout the cells of the atria, which then passes through the atrioventricular (AV) node down into the ventricles. This is the normal progression of electrical events.

Answer 4

There are specialized areas of cardiac muscle tissue (1%) in the heart that are autorhythmic (self-exciting). These cells compose the conduction system and are responsible for initiating and distributing cardiac (electrical) impulses throughout the heart muscle (i.e. cause the heart to beat).
These specialized areas together coordinate the events of the cardiac cycle, which makes the heart an effective pump.

Sinoatrial Node (S-A Node) is located in right uppermost atrial wall. It is often called the PACEMAKER and is self-exciting tissue (rhythmically and repeatedly [60-100 per minute) which begin cardiac impulses. It doesn't require any other nerve impulse and beats on its' own.

Answer 5

A small cluster of cells called the sinoatrial nodes initiate the contraction of the heart.

Answer 6

the outer side