What do cells in the CCS do?
Cardiac Conduction System (CCS) is a system in the heart which are not part of the nervous system but can be sped up or slowed down by the nervous system.
There are specialized areas of cardiac muscle tissue (1%) in the heart that are autorhythmic (self-exciting).
These cells compose the CCS and are responsible for initiating and distributing cardiac (electrical) impulses throughout the heart muscle, causing the heart to beat.
These specialized areas together coordinate the events of the cardiac cycle, which makes the heart an effective pump.
Components of the CCS:
The Sinoatrial Node (S-A Node) is located in right uppermost atrial wall. It is called the primary pacemaker and it is a self-exciting tissue (rhythmically and repeatedly [60-100 per minute] and initiates cardiac impulses).
Atrioventricular Node (A-V Node) is located in interatrial septum and serves as a delay signal that allows the ventricles to fill. This node can act as a backup pacemaker but it is slower.
Atrioventricular (AV) Bundle (Bundle of His) is only an electrical connection between the atria and ventricles and located in the superior interventricular septum.
Right and left bundle branches each carry an impulse downward through the interventricular septum to the apex.
Purkinje Fibers (Conduction Myofibers) have large diameter conduction myofibers. These are located within the papillary muscles of the ventricles and conduct the impulse into the mass of ventricular muscle walls.
As far as the questions about after death, if the body still breathes and still takes in nutrients, the heart will continue to beat.
But if the person is brain dead, they will be removed from any artificial breathing and nourishment and the heart muscle will die. And the heart will stop beating.
When we die, we stop breathing and our hearts stop beating. Our blood stops circulating and cells become depleted of nutrients, water, and oxygen. Our starved, dehydrated, deoxygenated cells begin to die. The chemical and biological components of the cells break down. Dead cells are not biologically or chemically like living cells.
The lack of nutrients, water, and oxygen kills the cells of the body, including heart cells and the specialized pacemaker SA and AV nodes. When the SA and AV nodes die, they can no longer send the electrical signals to the heart cells to make them beat, so the heart stops beating.
There is nothing mystical going on. When cells don't get enough oxygen, water, and food, they die. The electrical system of the heart shuts down due to starvation and lack of oxygen, causing the death of the heart cells, including the pacemaker SA and AV nodes that produce the electrical system of the heart that controls its beating.