What is the flap that opens and closes to allow blood into the veins to travel in Only One Direction?

What is Flu mil 500? tell you about a time when it was important to involve someone in a conversation? Name Two factors that affect labor supply? Is there a pill that you can take for yeast infections instead of creams? How does body position affect lung? Does Vitamin C make blood thinner than usual? What is mitral facies in mitral stenosis? Can you get anorexia in 2 months? Where did king ferndand of Spain grown up? Which bone cell types is primarily responsible for initiating ossification of a bone? How do dandruff spread? Can the same virus infect someone twice? What race has mostly B negative blood type? Do nipples always get erected? What is this Lee Reynolds painting worth -- a 48 x 60 canvas white star-burst of pastel purples blue-greens predominately? If you eat paper with ink on it will you die? What are the effects dissociative identity disorder have on the brain? What fad of 1961 could be purchased with fake windows to help owners overcome claustrophobia? How do you prevent yeast infections while taking antibiotics? Can salmonella stay in your stomach and recur months later?