The correct answer is: 3- Atrioventricular valves
Heart valves are structures in heart that allow blood flow in only one direction. The valves of heart can be divided in two groups:
1. Atrioventricular valves (AV valves), located between atria and ventricle and they prevent backflow of blood from the ventricles into the atria.
• Mitral valve-between left atrium and left ventricle
• Tricuspid valve-between right atrium and right ventricle
2. Semilunar valves (SL valves) located between ventricles and arteries and they prevent the backflow of blood into the ventricle
• Pulmonary semilunar valve- between the right ventricle and the pulmonary trunk
• Aortic semilunar valve - between the left ventricle and the aorta
