Which muscle controls the contractions of the heart?

Answer 1

Officially the sino-atrial (SA) node sets the rhythmic pace of the heart. The impulse from the SA node that signals the atria to contract is slightly slowed down at the AV node. The effect of this delay is that the ventricles receive the impulse to contract a split second later and so the heart can function as its supposed to. Without that split second delay all four chambers would be contracting nearly simultaneously, and the heart would not be able to function efficiently.

Also included are the AV bundle, and Purkinje fibers. These are made up of modified cardiac muscle.

AV bundle originates in AV node, extends by two branches down the two sides of the interventricular septum, and continues as Purkinje fibers. Purkinje fibers extend out to papillary muscles and lateral walls of ventricles. The nerve supply consists of sympathetic nerves-accelerator nerves and

Vagus fibers-inhibitory, or depressor, nerves.

Answer 2

There are a specialized group of cells in the heart called the AV node. These cells fire to keep the heart beating regularly.

Answer 3

The heart is composed of it own specail kind of muscle. IE cardiac muscle

The contraction is controlled by nodal cells which are unique in the body.

Answer 4

calcium