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.
Red blood cells (also called erythrocytes) make up about 40% of the blood's volume. Red blood cells contain hemoglobin, a protein that gives blood its red color and enables it to carry oxygen from the lungs and deliver it to all body tissues.hite blood cells (also called leukocytes) are fewer in number than red blood cells, with a ratio of about 1 white blood cell to every 600 to 700 red blood cells. White blood cells are responsible primarily for defending the body against infection. There are five main types of white blood cells.