Touching Lives - July 2008
Bronchioles You may have heard it said that the area inside your lungs, in which the gas exchange takes place, is the size of a tennis court, and this may well be true! The lungs hold a very large number of tiny sacs called alveoli, arranged rather like the leaves on a tree. The air gets to and from these sacs through a branching system of tubes starting with the windpipe (trachea), and branching into the two bronchi, which in turn branch and branch again until they come to the very last ones leading into the alveoli. These are the bronchioles.
Enzymes Think of enzymes as biochemical tools. They can change a substance, like a protein eaten as food, into something the body requires — without getting used up in the process. Just like a carpenter using his hammer and saw over and over again to process many pieces of wood. Thousands of different enzymes are used by the body; without them nothing could be achieved. It would be like a world without tools.
Neutrophils There are something like five million cells in every cubic millimetre (or micro-litre) of blood, most of which are red blood cells. However, about 4,000 are white blood cells, and the majority of these are neutrophils. Neutrophils represent both the first-line army and the weapons which the body uses to fight invasion by bacteria. A chemical message is received that bacteria are about and the neutrophils rush to the scene, able to penetrate the walls of blood capillaries in the process, in order to reach the tissues. They ‘eat’ the bacteria using chemicals (often enzymes) in granules that they carry to kill them. The neutrophils sacrifice themselves in the process, but there is a factory in the bone marrow which continuously produces more.