HEART

Heart
The heart is a hollow muscular organ located between the lungs. It works to pump blood throughout the body. The heart is divided into four chambers: two upper and two lower. The upper chambers called atria. They are also the right atrium and the left atrium. At the bottom is a space called the ventricle where the left ventricle and the right ventricle.
• The heart is composed of layers:
• endocardium (connective tissue membrane.)
• Elastic and special collagen fibers.
• Blood vessel.
• trabecular, which confers resistance to improve heart contraction.
• Myocardium, heart muscle that has a specific function sends blood pushing against blood stream for distribution.
• pericardium, the membrane that surrounds the heart as a whole and form a pocket.