Your heart is a muscle about the size of your fist. Compare it to other muscles. Can you control it like you do the muscles in your arms or legs? Can you exercise it like you do other muscles? ( One Paragraph)

The heart muscle, or myocardium, has shorter and thicker fibers —capable of generating action potential— compared to skeletal muscle, both of which are different from visceral smooth muscle. It is an involuntary muscle and cannot be exercised like the striated muscle of the limbs.

Explanation:

The heart muscle is called the myocardium and is made up of specialized cells called cardiomyocytes. It is a muscle with a striated appearance, like skeletal muscle, but with a different structure and function:

Both types of muscle are different from the visceral smooth muscle.

No, the cardiac muscle is involuntary and with automatic activity, regulated by the sympathetic and parasympathetic nervous system.

No, the heart muscle develops its activity without the need to be exercised. However, its fibers can hypertrophy and increase with the effort of its pumping activity, as happens in high blood pressure. This is not a good thing and is linked to cardiovascular disease.

the correct answer is d