Blood moves from the atria to the ventricles through which valves?

1- semilunar valves

2- aortic valves

3- atrioventricular valves

4- ventricular valves

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

the correct answer should be false

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1. high progesterone levels maintain the endometrium lining of the uterus.

2. endometrium lining breaks down and low levels of estrogen stimulate the pituitary to release fsh and lh.

3. fsh and lh stimulates the follicles to develop and the oocyte to produce estrogen.

4. rising estrogen levels suppress fsh production and development of other follicles.

5. a spike in lh causes follicle to rupture.

6. a breakdown of corpus luteum causes progesterone level to drop."