20 BOY SCOUTS OF AMERICA Campmasters With the exception of summer camp programs, our camps are served by campmasters â volunteers who staff the office, provide weekend programs, serve our campers and ensure the safety and well-being of our visitors.
In humans, mature red blood cells are flexible and oval biconcave disks. They lack a cell nucleus and most organelles, in order to accommodate maximum space for hemoglobin. Approximately 2.4 million new erythrocytes are produced per second in human adults. The cells develop in the bone marrow and circulate for about 100â120 days in the body before their components are recycled by macrophages. Each circulation takes about 20 seconds. Approximately a quarter of the cells in the human body are red blood cells.
In a normal adult the red cells of about half a litre (almost one pint) of blood are produced by the bone marrow every week. Almost 1 percent of the bodyâs red cells are generated each day, and the balance between red cell production and the removal of aging red cells from the circulation is precisely maintained. The rate of blood cell formation varies depending on the individual, but a typical production might average 200,000,000,000 red cells per day, 10,000,000,000 white cells per day, and 400,000,000,000 platelets per day.