Circulatory system of the horse capacity of the muscular system far exceeds the capacity of the cardiovascular system to deliver oxygen. Blood is made up of red blood cells (erythrocytes) and white blood cells (leukocytes), as well as plasma. Produced in bone marrow, red blood cells are responsible for carrying oxygen to tissue and removing carbon dioxide, all via hemoglobin. White blood cells are used for defense against pathogens in the immune system. Plasma suspends the blood cells, contains clotting factors, and contributes to the greatest volume of blood. The heart and blood vessels contain approximately of blood in a horse, which equates to about
Fatty acid metabolism Adipose tissue cells store the triglycerides in their fat droplets, ultimately to release them again as free fatty acids and glycerol into the blood (as described above), when the plasma concentration of insulin is low, and that of glucagon and/or epinephrine is high. Mammary glands discharge the fat (as cream fat droplets) into the milk that they produce under the influence of the anterior pituitary hormone prolactin. All cells in the body need to manufacture and maintain their membranes and the membranes of their organelles. Whether they rely for this entirely on free fatty acids absorbed from the blood, or