Question

Which type of muscle is found in the heart?
A. Smooth muscle
B. Skeletal muscle
C. Cardiac muscle
D. None of the above.

Answer 1

Hint: The heart muscles are also known as the myocardium. These are striated muscles that make the blood-pumping organ of the body. These muscles receive blood via the coronary sinus.

Complete answer: Cardiac muscles are the muscles that have involuntary functions. It is present in the heart. This muscle cannot be controlled by humans; they continuously contract and relax. The cells of the cardiac muscles are uninucleated and have a single nucleus. They are cylindrical, elongated, striated, and branched in shape; these cells are called cardiomyocytes. The cardiac muscles help in the coordination of the muscle contraction and it also maintains the circulation of the blood. They have the striations due to the presence of the filaments which are arranged into the sarcomeres. The cardiac muscles have more mitochondria and therefore, it can resist fatigue. These mitochondria provide energy which results in the continuous beating. These muscles are myogenic, that is, the contraction is generated within the muscle. These muscles are joined together by the intercalated discs which have a gap junction between them. Each cardiomyocyte needs to contract in coordination with its neighbouring cells, known as a functional syncytium.
Hence, the correct answer is option C.

Note: In the vertebrate body, there are mainly three types of muscles: the skeletal muscles which are the striated, voluntary, unbranched, and multinucleated. The second is the smooth muscle, which is non-striated, involuntary, branched and uninucleate and the third is the cardiac muscle of the heart.