Describe the structure of human heart. …

Structure of Human Heart

• The heart is a muscular organ covered by a double membrane called pericardium.
• The pericardial fluid of the pericardium lubricates the heart.
• The heart is divided into four chambers — two upper atria and two lower ventricles.
• The inter-atrial septum separates the two atria and the inter-ventricular septum separates the two ventricles.
• The atrium and the ventricle of each side are separated by the atrioventricular septum.
• Superior and inferior vena cavae open into the right atrium.
• The right ventricle opens into the pulmonary artery.
• Four pulmonary veins open into the left atrium.
• The left ventricle opens into the aorta.
• The opening between the right atrium and right ventricle is guarded by the tricuspid valve.
• The opening between the left atrium and left ventricle is guarded by the bicuspid (mitral) valve.
• The opening of the right ventricle into the pulmonary artery and the opening of the left ventricle into the aorta is guarded by the semilunar valves.