Systemic circuit circulates blood through rest of body. Pathway to and from body organs begins with the left ventricle. Blood Blood helps maintain homeostasis. Blood transports molecules to and from capillaries. Blood guards body against microbial invasion.
Blood reduces blood loss by clotting.
Carry Oxygen i. Continuously formed in red bone marrow of skull, ribs, vertebrae, and ends of long bones. 4- 6 million red blood cells per mm 3 of whole blood. Each red blood cell contains about 200 million hemoglobin molecules. Hemoglobin provides red color of blood.