Medical scientist

    The heart is a muscular organ that pumps blood throughout the body. The heart has four chambers: the left and right atria, and the left and right ventricles. The atria are the upper chambers of the heart, and the ventricles are the lower chambers. The right side of the heart pumps blood to the lungs, and the left side of the heart pumps blood to the rest of the body. The heart is made up of three layers: the outer layer, the middle layer, and the inner layer. The outer layer is called the epicardium. The middle layer is called the myocardium. The inner layer is called the endocardium. The heart has four valves: the tricuspid valve, the pulmonary valve, the aortic valve, and the mitral valve. The tricuspid valve is located between the right atrium and the right ventricle. The pulmonary valve is located between the right ventricle and the pulmonary artery. The aortic valve is located between the left ventricle and the aorta. The mitral valve is located between the left atrium and the