Cardiac muscle tissue is one of the three types of muscle tissue in your body. The other two types are skeletal muscle tissue and smooth muscle tissue. They are found only in the heart and are self-stimulating, which has an intermediate speed of contraction and energy requirement. This muscle is not part of the musculoskeletal system. Cardiac muscles are striated muscles, which are responsible for keeping our heart functioning by pumping and circulating blood throughout the body and performing muscular involuntary movements. They are involved in continuous rhythmic contraction and relaxation. The interconnected muscle cells or fibres provide strength and flexibility to the cardiac muscle tissue.
Structure of Cardiac Muscles
Cardiac muscle exists only within the human heart. It is a specialized form of muscle evolved to continuously and repeatedly contract, providing circulation of blood throughout the body. Cardiac muscle has a regular pattern of fibres similar to that of smooth muscles. These muscles comprise cylindrical, branched fibres and a centrally located nucleus. The T-tubules or transverse tubules are rich in ion channels and are found in the atrial muscle cells. These muscles are striated muscles with cylindrical-shaped cells, which includes intercalated discs and joins neighbouring fibres.
Functions of Cardiac Muscles
The primary function of these muscles is to regulate the functioning of the heart by the relaxation and contraction of the heart muscles. Other functions of cardiac muscles include:
- The cardiac muscles function as involuntary muscle.
- Involved in movement or locomotion.
- They work without stopping, day and night. They work automatically and make the heart contract so that the heart can squeeze the blood vessels and release them so that the heart can fill up with blood again.
- The heart comprises a specialized type of cardiac tissue, which consists of “pacemaker” cells. These contract and expand in response to electrical impulses from the nervous system.