human heart Structure and Function | Chapter Circulation Video # 2 скачать в хорошем качестве

human heart Structure and Function | Chapter Circulation Video # 2

HUMAN HEART The heart is a muscular organ roughly the size of a closed fist. It sits in the chest, slightly to the left of center. • One of the primary function of the human heart is to pump blood throughout the body. • Blood delivers oxygen, hormones, glucose and other components to various parts of the body, including the human heart. • The heart also ensures that adequate blood pressure is maintained in the body The heart, blood, and blood vessels combined are referred to as the circulatory system. An average human has around 5-6 liters of blood, which is constantly pumped throughout the body. Basic anatomy of the heart The heart consists of four chambers: • Atria: the two upper chambers (they receive blood). • Ventricles: the two lower chambers (they discharge blood). The left atria and left ventricle are separated from the right atria and right ventricle by a wall of muscle called the septum. The wall of the heart consists of three layers of tissue: • Epicardium — protective layer mostly made of connective tissue. • Myocardium — the muscles of the heart. • Endocardium — lines the inside of the heart and protects the valves and chambers. Furthermore, it prevents the blood from sticking to the inner walls, thereby preventing potentially fatal blood clots. These layers are covered in a thin protective coating called the pericardium. The pericardium is a fibre membrane found as an external covering around the heart. It protects the heart by producing a serous fluid, which serves to lubricate the heart and prevent friction between the surrounding organs. Apart from the lubrication, the pericardium also helps by holding the heart in its position and by maintaining a hollow space for the heart to expand itself when it is full. And heart contains vessels for the transport of blood Blood Vessels Veins Arteries Capillaries Types of Circulation • Pulmonary circulation is a portion of circulation responsible for carrying deoxygenated blood away from the heart, to the lungs and then brings oxygenated blood back to the heart. • Systemic circulation is another portion of circulation where the oxygenated blood is pumped from the heart to every organ and tissue in the body, and then back again to the heart. Human heart function The heart circulates blood through two pathways: the pulmonary circuit and the systemic circuit. In the pulmonary circuit, deoxygenated blood leaves the right ventricle of the heart via the pulmonary artery and travels to the lungs, then returns as oxygenated blood to the left atrium of the heart via the pulmonary vein. In the systemic circuit, oxygenated blood leaves the body via the left ventricle to the aorta, and from there enters the arteries and capillaries where it supplies the body's tissues with oxygen. Deoxygenated blood returns via veins to the venae cavae, re-entering the heart's right atrium. Of course, the heart is also a muscle, so it needs a fresh supply of oxygen and nutrients, too, After the blood leaves the heart through the aortic valve, two sets of arteries bring oxygenated blood to feed the heart muscle done by coronary circulation. Coronary circulation is an essential portion of the circulation, where oxygenated blood is supplied to the heart. This is important as the heart is responsible for supplying blood throughout the body. The heart has four valves that help ensure that blood only flows in one direction: Aortic valve: between the left ventricle and the aorta. Mitral valve: between the left atrium and the left ventricle. Pulmonary valve: between the right ventricle and the pulmonary artery. Tricuspid valve: between the right atrium and right ventricle. #CardiovascularSystem #HumanHeartDiagram #HeartBasicAnatomy #HumanHeartAnatomy