Oxygen In The Body
The tissues of the body have to have oxygen to live. When the supply of oxygen is inadequate the condition is called “anoxia.” The shortage of oxygen may be apparent in the circulating blood. The red cells of the blood may be inadequate in amount or in the red coloring matter necessary to carry oxygen. Anything that blocks the circulation will also block the oxygen supply. Sometimes the cells of the body are unable, because of changes, to take up the oxygen that reaches them.
Since all parts of the body must have oxygen, a shortage will affect all of them. However, some tissues of the body are much more dependent on oxygen than are others. Most sensitive of all are the tissues of the nervous system. Sudden lack of oxygen to the nervous system results in impairment of judgment, lack of co-ordination of movements, and a condition which, in general, resembles that of a person who is drunk. After the lack of oxygen has persisted the person becomes fatigued, drowsy, inattentive, and unable to respond to ordinary stimuli.
If lack of oxygen to the brain persists, death will result from inability to breathe. A failure of sufficient oxygen to reach the liver and the muscles where foods are broken down to their ultimate condition for use by the body, results in acidosis and is therefore also incompatible with life. The increase in red blood cells and hemoglobin in response to anoxia may begin gradually and continue for weeks. At high altitudes the total increase may reach 40 per cent above the usual.
Cyanosis And Argyria
The word “cyanosis” means blueness, but in medicine it is restricted to the kind of blueness that follows a reduction in the amount of hemoglobin or red coloring matter in the blood. A condition called “argyria” which is due to deposit of silver in the skin gives a silvery-blue appearance. Blueness due to lack of oxygen in the blood is best seen in the lips, the white of the eye, the fingernail beds, the ears and the area over the cheek bones.
Certain poisonous substances including drugs may lead to cyanosis, by changing the nature of the hemoglobin or red coloring matter of the blood. Among these drugs are the nitrates which are sometimes used to dilate blood vessels and lower blood pressure. Also hydrogen sulfide and acetanilide may have this effect. When people are poisoned by carbon monoxide gas, the blood develops a cherry-red color rather than blue. Occasionally people who take sulfonamide drugs get bluish blood due to a chemical change.
When there is any interference with the flow of blood through the skin the color may seem blue or a pale bluish-gray. Such difficulty may come from a weak heart, an obstruction of the flow of blood or simple exposure of the skin to severe cold. Some people suffer constantly with cold and bluish hands and feet because of poor circulation in the extremities.
The doctor must determine whether the difficulty is due to the heart, or the lungs or some trouble in the blood itself. By special signs such as clubbing of the fingers, the duration of the condition in relationship to employment, examinations of the heart and lungs, and chemical and physical studies of the blood, he can make the distinction.
Too Many Red Cells-Polycythemia
Doctors put together names of diseases frequently out of portions of words. “Poly” means multiple or too many; “cyth” refers to cells; “emia” means the blood. An alarming increase in the number of red blood cells might also be called an erythrocytosis, which merely means a condition of the red blood cells. An excess number of the cells may develop as a result of an insufficient oxygen supply, such as occurs at high altitudes, or as a result of an excess manufacture, producing a disease the cause of which is not known. This true polycythemia is also called Osler’s disease and Vaquez’s disease after physicians who first noticed it.
Polycythemia comes on gradually and persists for ten or twenty years. The person with this condition has constantly a deep red flush which may have a bluish appearance. Usually the spleen and the liver are enlarged. The blood clots easily. Hemorrhages in various parts of the body are not uncommon. Whereas the blood count ordinarily is around five to six million, the count rises in this condition to nine to twelve million cells in each cubic millimeter of blood. Among unusual causes of secondary polycythemia, in addition to residence at high altitude, are disturbances such as silicosis, which interfere with receipt of oxygen by the lungs; abnormalities of circulation of the blood through the lungs; cases which occur in infants that have been unable to get a good oxygen supply before birth; and even certain tumors of the brain and failure of the adrenal glands. Among methods of treatment now used to control excess production of the cells are X-ray of the bone marrow, giving of radioactive phosphorus and use of the nitrogen mustards.
