The heart is a muscular organ having four chambers, each of which play a crucial role in pumping blood and circulating it throughout the body. In the human body, there are three types of muscles, of which the cardiac muscle is one of them. It is present in the protective wall of the heart, particularly concentrated in the myocardium part. Maintaining optimal strength of the muscle is crucial for normal functioning of the heart. It requires adequate supply of oxygen, failure of which causes impairment or even death of the muscle cells. Any abnormality in its structure brings about medical conditions, which may be mild to severe.
Cells of the Cardiac Muscle
The cells that made up the cardiac muscle are collectively referred to as cardiomyocytes. They contain multiple number of mitochondria, which allow aerobic respiration to take place constantly. The cells branch randomly and twine with each other, thus resembling a mesh. This gives strength to the heart walls to withstand increased pressure, subjected during repeated pumping of blood.
The unique nature of the muscle lies in the fact that it is present only in the heart, not in any other part of the body. It is involuntary in function. The presence of branched cells too make it unique. These cells are connected by means of intercalated discs.
In addition to the cardiomyocytes of the cardiac muscle, there are some specialized cells, called the pacemaker cells. They are responsible for initiating and controlling the heartbeat. Functionally, pacemaker cells regulate the electrical impulses of the heart, thus playing a direct role in maintaining the heart rate.
The muscle shares some features with the remaining two muscles, namely the smooth type and the skeletal type. It resembles the skeletal type with reference to multinucleate cells and a striped appearance. As far as similarity with smooth muscle is concerned, both cardiac and smooth muscle types bear a nucleus in the center.
One of the characteristics worth mentioning is perfect coordination of the cells during contraction and beating of heart. The major function of this muscle is pumping blood to the blood vessels for circulation throughout the body. For this purpose, it receive oxygen and nutrients via the coronary arteries.
The myocardial cells are responsible for contraction of the heart walls, which is crucial for pumping blood from the ventricle. Communication of the cardiomyocytes for contraction is done by means of the intercalated discs that are arranged properly in between the cells.
As you see, the characteristics of the cardiac muscle are distinctive, in comparison to other muscle types. Precisely speaking, its features are intermediary to the skeletal and smooth muscles. When you observe the heart muscle under a sophisticated microscope, the cells will appear striated. This is because of the protein filaments arranged in a particular manner. It is found that its cells have a very lesser rate of regeneration.