PLS HELP ME WITH THIS PLS HELP WOTH THIS ONE I TRUST YOU GUYS!! <\3 BOTH OF THESE PLSS HELP GUYSS THANK YOU BESTIEEE

Which of the following is the definition of ventilation as it relates to the respiratory system?

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.

What percent of body heat can be lost through the head