The Circulatory or Cardiovascular System. Figure 11.1. Cardiovascular System. Components (parts) Pump (heart) Interconnected series of tubes that continually move blood throughout the body Arteries & Arterioles (smaller arteries) Veins & Venules (smaller veins) Capillaries Blood
Iron is reused by the red bone marrow where stem cells continually produce more red blood cells.
Lack of enough hemoglobin results in anemia.
The kidneys produce the hormone erythropoietin to increase blood cell production when oxygen levels are low.
Red Blood Cells
White blood cells, which ward off infection. These cells, which come in many shapes and sizes, are vital to the immune system. When the body is fighting off infection, it makes them in ever-increasing numbers.
White blood cells protect the body from germs (bacteria and viruses) by attacking them either directly or by sending antibodies 9sticky proteins that trap them.
If your blood type is . . continually produce more red blood cells. .