Human Circulatory System
Human Circulatory system consist of heart , blood vessles & blood. Heart is mesodermal in nature. It is situated in the thoracic cavity , in between the two lungs.
The double membrane that surround the heart is known as Pericardium. Pericardium circles the pericardial luid. Heart is 4 chamber with 2 upper small atria & 2 lower long ventricles. A thin wall seperates the left & right atria called Intra-atrial septum. The left & the right ventricles are seperated by thick Intra-ventricular septum .
The double membrane that surround the heart is known as Pericardium. Pericardium circles the pericardial luid. Heart is 4 chamber with 2 upper small atria & 2 lower long ventricles. A thin wall seperates the left & right atria called Intra-atrial septum. The left & the right ventricles are seperated by thick Intra-ventricular septum .
The opening between the right atrium & right ventricles is guarded by a valve know as Tricuspid Valve. The Bicuspid Valve guards the opening between left atrium & left ventricles . The opening of right & left ventricles inton the pulmoery artry & the aorta. respectivelyare provided with the semilunalr valve. This valve in the heart allows the blood to flow in one dorection & thus preventing backflow of blood.
Heart is a muscular organ. Haert muscle is known as Cardiac Muscle. A specialized cardiac musculature called the Nodal tissue is also dispersed in the heart. One is present in the upper left corner of the the right artrium called Av node .
A bundle of nodal fibres, Av bundle contnues from the AVN which passes through the atria-ventricular septa & divides into right & left bundle. These branches give rise to minute fibres known as Purkinje Fibres. SA node is known as the Pacemaker of the heart as it has the ability to get excited & can genertaes an action potential.
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