Why does the heart automatically adjust the flow of blood to match activity levels?
a.
extreme activity damages blood cells and the body needs replacements.
b.
the heart requires more oxygen when exercising.
c.
it builds up a higher level of oxygen in the blood.
d.
organs and muscles require more blood under stress.

Which of the following must be cooked to 145º f? a. chicken and stuffing b. ground beef and eggs not served immediately c. beef roasts and seafood d. all of these must be cooked to 145° f.

Select two risk factors for self-harming behavior. a. having high self-esteem b being a teenager or young adult c. being female d. having never abused drugs or alcohol i know its going to be something funny and i'm gonna feel dumb asking it but its for my final test of the semester

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.