What is the relationship between promoting healthy behaviors, such as avoiding tobacco, and preventing disease?

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.

Aproper cool-down routine includes which of the following? a). eating a good-sized meal b. five to 10 minutes of slow walking or jogging and stretching c). less than 5 minutes of cool-down stretches d). sprinting or other strenuous exercise

Why mature red blood cells has no nucleus