Health effects of tobacco the blood thicker and more likely to clot. Carbon monoxide binds to hemoglobin (the oxygen-carrying component in red blood cells), resulting in a much stabler complex than hemoglobin bound with oxygen or carbon dioxide—the result is permanent loss of blood cell functionality. Blood cells are naturally recycled after a certain period of time, allowing for the creation of new, functional red blood cells. However, if carbon monoxide exposure reaches a certain point before they can be recycled, hypoxia (and later death) occurs. All these factors make smokers more at risk of developing various forms of arteriosclerosis (hardening of the arteries).
Red blood cell (the remaining oxygen is carried dissolved in the blood plasma). The red blood cells of an average adult human male store collectively about 2.5 grams of iron, representing about 65% of the total iron contained in the body. Red blood cells in mammals "anucleate" when mature, meaning that they lack a cell nucleus. In comparison, the red blood cells of other vertebrates have nuclei; the only known exceptions are salamanders of the genus "Batrachoseps" and fish of the genus "Maurolicus". The elimination of the nucleus in vertebrate red blood cells has been offered as an explanation for the subsequent accumulation