Heart, blood and blood vessels composed the cardiovascular system. Cardiovascular system is the transporting system that transport the respiratory gases, nutrients, enzymes, vitamins and drugs into throughout the body by blood. Heart, Where comes blood for oxygenated (purify) and blood vessels where blood flow in these vessels.Anatomy of The Heart   Heart is vital organ in living body. Heart is pumping, conical and hollow organ. Heart present in the pericardial cavity. Location of the heart The heart is rest on the diaphragm lies on thoracic cavity between the lungs and behind the sternum. two third (2/3) part of heart is on the left side. Heart is about 12 cm long, 9 cm wide at its broadest point, 6 cm thick with an average weight of 300 gm in adult male and 250 gm in adult females.Pericardium (Surrounds Membrane)Pericardium membrane that surrounds and protects the heart. Pericardium consist of two main layers.1) Fibrous membrane – fibrous pericardium is superficial membrane that composed of inelastic, tough and dense connective tissue. this pericardium prevents over stretching of the heart and provide the protection.     2) Serous pericardium – serous pericardium is deeper membrane that is a thinner and more delicate membrane that forms a double layer around the human heart. Parietal layer – outer serous pericardium is parietal layer that is fused with fibrous pericardium. Visceral pericardium – inner serous pericardium is visceral layer that adheres tightly to the surface of the heart.Between the parietal and visceral pericardium of the serous pericardium is a film of lubricating serous fluid called that fluid paricardial fluid.Layer of heart wallThe heart wall composed with three membrane -Epicardium (External/outer layer)Myocardium (Middle layer)endocardium (inner/deeper layer)Chambers of Heart The heart has four chambers, two superior receiving chambers are the atria (auricle) and two inferior pumping chambers are ventricles. these chamber are discussed following :Right Atrium – first chamber is right atrium where blood receives from three veins : superior vena cava, inferior vena cava and coronary sinus. superior vena cava collect all deoxygenated blood from the upper body part, inferior vena cava collect all deoxygenated blood from peripheral body and coronay sinus collect blood from itself heart tissue. partition between the right atrium and left atrium is a thin septum called the intratrial septum. blood transfer from the right atrium to right ventricle through the valve that is called the tricuspid valve and it is also called the right atrioventricular valve.Right Ventricles – Blood passes from the right atrium to right ventricle through tricuspid valve. blood comes in right ventricles and close tricuspid valve a sound obtained i.e. LUBB. between the right ventricle and left ventricle is a partition called the intraventricular septum. blood passes right ventricle to pulmonary artery through pulmonary valve and blood reach into the lungs. in lunges blood leaves co2 molecules and attached oxygen molecules (blood get oxygenated in lungs).Left atrium – it receives oxygenated blood from lungs through pulmonary veins. left atrium has the same thickness as the right atrium. a valve is present in the between left atrium and left ventricle, called bicuspid valve (Mitral valve). blood passes the left atrium to left ventricle through bicuspid valve.Left ventricle – the left ventricle is the thickest chamber i.e. 10-15mm. it receives the blood from left atrium through bicuspid valve and valve is closed a sound obtained i.e. DUPP. the oxygenated blood passes to the arch of the aorta (ascending aorta, descending aorta and coronary arteries) through aortic valve (aortic semilunar valve). aorta is a larger artery that supplies the oxygenated blood to whole body.Heart valve                Atrioventricular Valve (AV valve) – That valve located in between the atrium and ventricles. two types of AV valve are there  present one is present in between right atrium and right ventricle and second valve present in left atrium and left ventricle. these are two types valve :-tricuspid valve : Tricuspid valve present in between the right atrium and right ventricle. they are compose with three cusps or leaflets. tricuspid valve generate the first sound of heart i.e. LUBB.  Bicuspid valve – Bicuspid valve present in between the left atrium and left ventricle. that is composed with two cusps or leaflets. bicuspid value generate the second sound of heart i.e. DUPP.Semilunar Valve – that valve located in between the aorta and pulmonary. Semilunar valve passes blood from the ventricles into arteries but they prevent back flow of blood into the ventricles. Pulmonary Valve : Pulmonary valve is present in the pulmonary artery that valve opened in the right ventricles. pulmonary valve allow blood passes to the right ventricle to lung through pulmonary artery. Aortic valve : Aortic valve is present in the aorta artery which supply the oxygenated blood to throughout the body. Function Of HeartHeart is a pumping organ. Heart is involve in circulating blood throughout the body. heart, where all deoxygenated blood comes from body and supply oxygenated blood to throughout body. Heart is working as following :Deoxygenated blood comes from all body into right atrium through superior vena cava, inferior vana cava and coronay sinus. blood passes right atrium to right ventricle by tricuspid valve.Right ventricle receive blood from right atrium and valve is closed, sound produced i.e. LUBB. blood passes to the right ventricle to lungs through pulmonary valve for oxygenation process. in oxygenation process, blood comes in lungs that carry carbon dioxide molecules where blood remove carbon dioxide molecule and attached oxygen molecules. blood get oxygenated in lungs.Now left atrium is receives oxygenated blood. blood passes left atrium to left ventricle through bicuspid valve.Bicuspid valve is closed and sound generate i.e. DUPP. Left ventricle receives blood from left atrium. left ventricle transfer the blood into the aorta though aortic valve that blood circulate throughout body.