Question

Which of the following statements about cardiac muscle is true? a. Cardiac muscle is like smooth muscle, because smooth muscle has a banded appearance. b. Cardiac muscle is like smooth muscle, because it contains no bands. c. Cardiac muscle contains bands like skeletal muscle, but its contractions are involuntary like smooth muscle. d. Cardiac muscle is like skeletal muscle, because skeletal muscle has involuntary contractions.

Answer 1

Answer:

c. Cardiac muscle contains bands like skeletal muscle, but its contractions are involuntary like smooth muscle.

Explanation:

In Human anatomy, cardiac cycle can be defined as a complete heartbeat of the human heart which comprises of sequential alternating contraction and relaxation of the atria and ventricles, therefore causing blood to flow unidirectionally (one direction) throughout the human body.

Cardiac muscle is also referred to as myocardium and it's one of the three (3) muscles found only in the heart of vertebrates, the other two (2) being smooth muscle tissue and skeletal muscle tissue.

Cardiac muscle contains bands like skeletal muscle referred to as sarcomeres (contractile units), but its contractions are involuntary like smooth muscle and it's typically being regulated by the sinoatrial node of the heart.