Nearby USPS - Postal Service Locations. 1  225 S Van Rensselaer St, Rensselaer (0.1 mi) 2  120 W Harrison St, Rensselaer (0.1 mi) 3  200 W Washington St, Rensselaer (0.2 mi)
Production of red blood cells is controlled by erythropoietin, a hormone produced primarily by the kidneys. Red blood cells start as immature cells in the bone marrow and after approximately seven days of maturation are released into the bloodstream.lood is a specialized body fluid. It has four main components: plasma, red blood cells, white blood cells, and platelets. Blood has many different functions, including: 1  transporting oxygen and nutrients to the lungs and tissues.
Blood cells are made in the bone marrow and in the spleen. The bone marrow is the soft material in the middle of bones. Special cells in the bone marrow make most of the blood cells in your body. Plasma proteins are made mostly by the liver. The water and electrolytes in plasma come from the food and water that you eat. Although blood is a fluid, in some respects it is a kind of connective tissue.