Question

Which of the following layers of heart contracts and relaxes to facilitate the flow of blood?

• A. Pericardium
• B. Myocardium
• C. Endocardium
• D. All of the following

Answer 1

The correct option is B Myocardium

The heart is made up of 3 layers- pericardium, myocardium and endocardium.
Pericardium is the protective covering around the heart. It is a double walled bag. It contains the pericardial fluid in between the two layers which act as a lubricant and protect the layers from wearing away due to friction.
Myocardium is the middle muscular layer of the heart which contracts to pump blood out of the heart and then relaxes as the heart refills with returning blood.
Endocardium is the innermost layer in contact with blood.