Answer :
Final answer:
The pulmonary valves are responsible for preventing the backflow of blood from the right ventricle to the pulmonary artery by closing during the contraction of the ventricle.
Explanation:
The structures that protect the orifice between the right ventricle and the pulmonary artery are the Pulmonary valves. These valves act as barriers that prevent the backflow of blood into the lower chambers of the heart, which are the ventricles, during heart contraction. To give an example, when the right ventricle contracts, the pulmonary valve closes to ensure that blood flows in the right direction, towards the lungs and not backward.
Learn more about Pulmonary valves here:
https://brainly.com/question/32564902
#SPJ11
