Valves Of The Heart Flashcards
What are cardiac valves evolved to allow?
Unimpeded unidirectional flow
What could allow blood to re-enter the heart from the pulmonary aorta and artery?
Relaxation of the ventricles
What do valves prevent?
Backflow of the blood
Where are atrioventricular valves (AV) found?
Between the atria and ventricles - prevent backflow during systole
What do the AV valves consist of?
Leaf shaped cusps
What forces the cusps together?
The increase pressure in the ventricles during systole - form a tight seal
What are attached to the cusps?
Papillary muscles and chordae tendineae
Where is the tricuspid valve found?
Between the right atrium and ventricle
How many cusps does the tricuspid vale contain?
3
How many cusps does the bicuspid valve contain?
2
Where is the bicuspid valve found?
Between the left atrium and ventricle
Describe semilunar valves
The valves between the ventricles and great vessels
What do semilunar valves prevent?
Prevent backflow of blood into the heart during diastole
Where is the aortic valve found?
Between the left ventricle and aorta
Where is the pulmonary valve found?
Between the right ventricle and pulmonary artery
How many cusps do the semilunar valves contain?
3 cusps
What are these spaces behind the aortic vales known as?
Aortic sinuses
What does backflow back towards the heart to do the sinuses?
At the end of the systole it cases the sinuses to fill with blood, ballooning and closing the valve
How many aortic sinuses are there?
3, one formed above each individual leaflet
What is found within the region of the sinuses?
Thickness of the wall is decreases and the luminal diameter is increased
What are the sinuses important for functionally?
Maintaining the patency of the valve leaflets during systole
What is the superior margin of each sinus marked by?
By a thickening term bed the supravalvar ridge
What is a heart murmur caused by?
By blood leaking through an incompletely closed or excessively narrowed (stenosed) valve
