An eco-cardium is a type of ultrasound test that measures sound waves as they bounce off the different parts of a person's heart which of these is the best model

Check all that occur during ventricular systole. a. the av valves open to allow blood to enter the ventricles from the atria. b. the av valves open to allow blood to enter the ventricles from the atria. c. the semilunar valves remain closed throughout systole to prevent backflow of blood into the ventricles. d. the semilunar valves remain closed throughout systole to prevent backflow of blood into the ventricles. e. the semilunar valves open to allow blood to flow into the large arteries. f. the semilunar valves open to allow blood to flow into the large arteries. g. the av valves close to prevent backflow of blood into the atria.

Christopher came down with the chicken pox after spending time in his child’s day care. what like in the chain of transmission is this scenario

The tissues of the arms and leg can't survive for longer than without a continuous blood supply. 2 hours 1 hour 3 hours 4 hours