ANATOMY

Detailed explanation-1: -The muscles of the heart, termed the myocardium, make up the middle and thickest layer of the heart wall. This layer lies between the single-cell endocardium layer, which lines the inner chambers, and the outer epicardium, which makes up part of the pericardium that surrounds and protects the heart.

Detailed explanation-2: -The myocardium is thickest in the left ventricle, as the left ventricle must create a lot of pressure to pump blood into the aorta and throughout systemic circulation.

Detailed explanation-3: -The myocardium is mainly made up of two types of cells: cardiomyocytes and fibroblasts. Fibroblasts are distributed between cardiomyocytes, along with extracellular matrix (ECM), blood vessels, lymphatic vessels, and nerve endings.

Detailed explanation-4: -Cardiac muscle tissue, or myocardium, is a specialized type of muscle tissue that forms the heart. This muscle tissue, which contracts and releases involuntarily, is responsible for keeping the heart pumping blood around the body.