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.
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 appears red because of the large number of red blood cells, which get their color from the hemoglobin. The percentage of whole blood volume that is made up of red blood cells is called the hematocrit and is a common measure of red blood cell levels.