Answer:

1.)arteries

2.)right atrium

3.)the four valves

4.)valves

5.)the left ventricle

Explanation:

sana maka help yan lang alam ko :))

answers :

1.Blood pressure is highest in arteries and lowest in veins.

2.The right atrium receives oxygen-poor blood from the body through the superior vena cava and the inferior vena cava and pumps the blood to the right ventricle.

3.Valves maintain direction of blood flow.

4.As the heart pumps blood, a series of valves open and close tightly. These valves ensure that blood flows in only one direction, preventing backflow. The tricuspid valve is situated between the right atrium and right ventricle.

5.The left ventricle pumps the oxygen-rich blood to the entire body. - The one-way valves which are present in the heart prevent the backflow of blood, so, Oxygen-rich and carbon dioxide-rich blood cannot be mixed. Hence, the correct answer is option (A).