Answer:
The cardiovascular system delivers oxygen, nutrients, hormones, and other important substances to cells and organs in the body. It plays an important role in helping the body meet the demands of activity, exercise, and stress. It also helps maintain body temperature, among other things.
We get tired after exercise because our muscle fibers get tired very quickly. This is due to the major source of energy for the muscle tissue, called adenosine triphosphate, or ATP. As the muscles make use of this supply of energy, they get tired and fatigue.
The answer is<span> blood cells that engulf and destroy pathogens
Phagocytes act as a protector of our body because they constantly ingesting the substances that they perceive as harmful to our body, which is very essential in determining our immune system.In general, One litre of humans blood contain around 6 millions of phagocytes cells in it.</span>
<span>"They are looking for the presence of antibody or complement on the surface of the RBC."
</span><span>The Coombs test is used to diagnose immune hemolytic anemias. It detects the presence of antibody or complement on the surface of the red cell. Answer choice A refers to direct antiglobulin test (DAT). Answer choice B refers to blood smear test. Answer choice C refers to iron stores test.</span>
The answer is: "when breathing stops from the lack of oxygen"
