The term myocardial refers to __. Question content area bottom Part 1 A. the muscle of the heart B. a structure between the atrium and ventricles of the heart C. the lining inside the heart D. the membrane around the heart
The correct answer and explanation is:
The term myocardial refers to A. the muscle of the heart.
Explanation:
The word myocardial comes from two parts: “myo-” meaning muscle, and “-cardial” referring to the heart. Thus, myocardial specifically relates to the heart muscle.
The heart is made up of three main layers:
- Endocardium – This is the thin lining inside the heart chambers, which helps blood flow smoothly within the heart. It corresponds to option C (the lining inside the heart).
- Myocardium – This is the thick, muscular middle layer of the heart wall. It consists of cardiac muscle tissue that contracts to pump blood out of the heart and into the rest of the body. This is the main working muscle of the heart, responsible for generating the force needed to circulate blood. This matches option A.
- Pericardium – This is the protective sac or membrane surrounding the heart, which provides lubrication and reduces friction as the heart beats. This corresponds to option D (the membrane around the heart).
Option B refers to a structure between the atrium and ventricles, which is the valve (like the mitral or tricuspid valve), not myocardial tissue.
Why is the myocardium important?
The myocardium is essential because it is the contractile tissue that enables the heart to function as a pump. When the myocardial muscle contracts (during systole), it forces blood from the atria to the ventricles and then from the ventricles to the lungs or the rest of the body. Without a healthy myocardium, the heart cannot effectively circulate blood.
Diseases affecting the myocardium, such as myocardial infarction (commonly known as a heart attack), can severely impair the heart’s ability to pump, leading to significant health consequences. This is why terms related to myocardial health are critical in cardiology.
In summary, myocardial specifically refers to the muscle layer of the heart responsible for its pumping action, making option A the correct answer.