What type of muscle tissue is primarily found in the heart?

• A. Skeletal muscle
• B. Cardiac muscle
• C. Smooth muscle
• D. Striated muscle

Answer: (B)

The primary type of muscle tissue found in the heart is cardiac muscle. This specialized muscle tissue is unique to the heart and is responsible for the involuntary contractions that pump blood throughout the body. Cardiac muscle cells, known as cardiomyocytes, are striated, meaning they have a banded appearance under a microscope, similar to skeletal muscle. However, unlike skeletal muscle, which is under voluntary control, cardiac muscle operates involuntarily and is regulated by the heart's intrinsic conduction system.

Cardiac muscle is designed for endurance and continual contraction, which is critical given the heart's role in maintaining blood circulation without tiring. The intercalated discs between cardiac muscle cells allow for rapid communication and synchronization of contraction, enabling the heart to function as an efficient pump.

In contrast, skeletal muscle is under voluntary control and is primarily associated with movement of the skeleton, while smooth muscle is found in the walls of hollow organs and is responsible for involuntary movements such as peristalsis in the digestive tract. Striated muscle refers to the appearance of both skeletal and cardiac muscle under a microscope, but it does not specify the unique characteristics of cardiac muscle that are essential for the function of the heart.