Valves Of The Heart Flashcards
What have cardiac valves evolved to do?
Allow unimpeded unidirectional flow from atria to ventricles or ventricles to great vessels.
If not for the valves what would happen?
Contraction of the ventricle walls would send blood both forwards, into the pulmonary artery and aorta, and backwards into the atria.
Relaxation of the ventricles would also allow blood to re-enter the heart from the pulmonary artery and aorta.
What do atrioventricular (AV) Valves do?
They prevent back flow of blood from the ventricles into the atria during systole.
What ensures proper closure and prevents inversion of the cusps of the AV valves?
Papillary muscles and chordea tendineae.
Where does the tricuspid valve lie between and how many cusps does it have?
Between the right atrium and ventricle and has three cusps.
Where does the mitral valve lie and how many cusps does it have?
Between the left atrium and ventricle and is the only heart valve to consist of just two cusps.
What is the function of the semi lunar valves?
They’re between the ventricles and great vessels, and they prevent back flow of blood into the heart during diastole.
What are the two semilunar valves?
Aortic valve- exists between the left ventricle and aorta.
The pulmonary valve- separates the right ventricle from the pulmonary artery.
What is the structure of the semilunar valves?
They consist of three cusps shaped like pockets. The spaces behind the aortic valves are known as aortic sinuses.
What is the function to of aortic sinuses?
Blood flow back towards the heart at the end of systole causes these sinuses to fill with blood, ballooning and closing the valve.
What are the two normal heart sounds?
Lub- corresponding with the closure of the atrioventricular valves.
Dub- corresponding to the closure of the semilunar valves.
What is a heart murmur caused by?
Blood leaking through an I completely closed or excessively narrowed valve.
