THE HEART

The heart is the muscular pumping organ that pumps blood round the blood.

EXTERNAL PART OF THE HEART

It surrounded by special tissue or hymen called pericardium. It is situated within the thoracic cavity. The outer part of the heart is attached to the breastbone and other structures in the thoracic cavity. The contraction and relaxation of the heart is aided by special muscle called myorcardium.


Figure External part of the heart

INTERNAL PART OF THE HEART

The internal part of the heart is lined with special tissues called endocardium. The heart of man consists of four chambers- upper two chambers, right and left auricles and two lower chambers- the right and left ventricles. The right and left parts of the blood are separated from each other by a wall of tissues called septum. The left and right auricles receive blood from the lungs and other parts of the body. While the left and right ventricles pump blood to all parts of the body. The right side of the heart distributes de-oxygenated blood to the pulmonary circulation, while the left side of the heart distributes oxygenated blood to the system and coronary circulation. Below is the internal structure of the heart.