Heart valve tricuspid valve has anterior, posterior, and septal cusps; and the mitral valve has just anterior and posterior cusps. The valves of the human heart can be grouped in two sets: 1- Two Atrioventricular (AV) valves to prevent backflow of blood from the ventricles into the atria a) Tricuspid valve, located between the right atrium and right ventricle. b) Bicuspid or mitral valve, located between the left atrium and left ventricle. 2- Two Semilunar valves to prevent the backflow of blood into the ventricle a) Pulmonary semilunar valve, located at the opening between the right ventricle and the pulmonary trunk. b)
Heart average cardiac output, using an average stroke volume of about 70mL, is 5.25 L/min, with a normal range of 4.0–8.0 L/min. The stroke volume is normally measured using an echocardiogram and can be influenced by the size of the heart, physical and mental condition of the individual, sex, contractility, duration of contraction, preload and afterload. Preload refers to the filling pressure of the atria at the end of diastole, when they are at their fullest. A main factor is how long it takes the ventricles to fill: if the ventricles contract more frequently, then there is less time to fill