 | Stages Of A Common Cold Developing
  Although scientists isolated at the South Pole may not catch colds often, when they do them get the disease the same way as a three-year-old who always seems to have a runny nose: A virus enters any of the passages leading to the throat and infects the tissues there. The stages of a common cold developing are examined in this article.
The most important of these passages is the nose. It is the first point of contact between harmful airborne substances and the body’s defenses against them. Its primary functions are to warm, moisturize and filter the roughly 500 cubic feet of air breathed each day — the equivalent of all the air contained in an empty room measuring 6 by 10 by 8 feet. The nose also acts as a resonance chamber for the voice. Finally—and almost incidentally in the human species—the nose functions as the organ of smell.
To carry out all these jobs successfully in so small an area requires that the architecture of the nose be extremely complex and efficient. The interior of the nose is divided into two chambers by a partition called the septum, made up of bone and a more flexible material called cartilage. With the possible exception of the Greek goddess Aphrodite, virtually no one has a perfectly shaped septum that divides the nose beautifully down the middle. Inmost mortals, the septum deviates to one side or the other, making one chamber slightly smaller— and slightly more prone to congestion— than the other.
Protruding partway from the outer walls of each chamber are three curled ridges or plates of bone that further subdivide the nasal cavity. Called turbinate’s, these plates multiply the nose‘s interior wall surfaces many times over. The surfaces are lined with a multilayered mucous membrane, which actually performs most of the nose’s duties as resident air conditioner.
This membrane is crammed with small blood vessels. Inhaled air passing over and around the turbinate’s is thus exposed to volumes of circulating blood and even in 10° F. weather is warmed to about 91° before it reaches the top of the throat. In very hot weather, the bloods vessels help absorb heat from the torrid air so that the air is cooled and does not damage the lungs.
The top layer of mucous-membrane cells, along with glands embedded in the membrane, carry out the nose’s humidifying — and, when necessary, cooling — action by constantly secreting a sticky fluid called mucus (hence the adjective “mucous”), more than a pint of it a day. The mucus may contribute about a pint of water per day to inhaled air, maintaining a relative humidity in the nose as high as 80 per cent. This is fundamental in the stages of the common cold developing.
This blanket of mucus is an essential protection against colds. It acts as a buffer between the upper respiratory system and irritating substances that may enter along with inhaled air. The mucus defends the tissue beneath it from a range of invaders — everything from dust particles to germs — either by destroying them with enzymes and other body chemicals or by keeping them suspended away from the vulnerable cells of the membrane until they are swallowed.
An army of minute, hair like cilia (not to be confused with the coarse visible hairs that screen the front of the nostrils against large airborne particles) continually advances the mucus through the intricate passageways of the nose. Beating as often as 1,000 times per minute, the cilia deliver the mucus blanket to the back of the mouth and eventually into the digestive tract, where it and its irritating passengers are destroyed by digestive fluids in the stomach.
Within the membrane is a small patch of nerve cells that take care of the sense of smell, transmitting their reactions to the brain along tiny nerve fibers. When you have a cold and your nose is congested and inflamed, these cells are often put out of action. Meals then seem disappointingly pallid, because what you can taste is always largely a matter of what you can smell—and with a cold you cannot smell very much.
Accessories to the marvelously efficient nasal machine are the sinuses, four groups of cavities in the bones of the skull (below). Two sinuses are located over the eyes, just above the eyebrows. Two others are just behind the bridge of the nose; just behind them, deep within the head, is another. The largest of the four groups lies in the cheekbones just below the eyes. These air-filled cavities serve to protect the brain from blows to the front of the head.
They are lined with mucous membrane, which serves as a supplemental source of mucus if for some reason the nasal secretions are inadequate. The sinuses normally drain into the nasal cavity through narrow canals. However, a cold or an allergic reaction can make the mucous membrane swell and block the canals, building up pressure that causes severe headaches.
Quite separate in function from the respiratory system but also important in colds are the tear ducts, located on either side of the bridge of the nose. They carry away the excess moisture produced by glands that constantly clean and lubricate the eyes. Like the sinuses, the tear ducts drain into the nasal cavity — which is why the seemingly innocent gesture of rubbing your eyes with your hands can give a cold virus entry into your body.. | Most Popular Common Cold And Flu ArticlesHow Does The Common Cold Affect Your Body Palpitations And Need To Cough Cough With Frothy White Sputum Types Of Rheumatic Heart Fever Pain Constant Low Grade Fever Nutritional Requirements Needed To Treat Fever Flu Symptoms With Neck And Back Pain And Muscle Aches Who Discovered Influenza Is Canada Ready For A Pandemic Influenza | |
| Behind and below the nasal cavity is the part of the throat called the pharynx, a vertical, nearly round passageway about five inches long in adults. The pharynx shuttles air toward the lungs while sending food, mucus and other materials toward the stomach.
The pharynx is also lined with mucous membrane to continue the work of warming, moisturizing and cleansing the air in the upper respiratory system. By the time air reaches the lungs, it will be close to normal body temperature and almost saturated with water.
Within the pharynx are two distinctly separate masses of spongy tissue, the tonsils and adenoids (opposite), which can be infected by viruses or bacteria. The tonsils, small, reddish, oval-shaped structures, lie at the base of the tongue, just behind the last lower molars. The adenoids, somewhat larger, are stationed on the roof of the throat at the back of the nasal passageways. Both the tonsils and the adenoids grow to their maximum size in early childhood. If left alone, they generally shrink after puberty until they all but disappear in adulthood.
Long regarded as unnecessary relics of evolution— and major sources of spreading infection— they were in past times routinely removed when a child reached his fourth or fifth year. Now, however, physicians usually leave these glands in place unless they become abnormally enlarged and repeatedly inflamed. Far from being useless appendages, the tonsils and adenoids actually are islands of defense, part of the body’s system for combating disease.
They store the white blood cells that attack and remove any foreign invaders, and they also release specific agents designed to defend the body against certain viruses and bacteria.
Close by the adenoids are the two Eustachian tubes, which lead from the middle chamber of each ear into the upper throat. The tubes are air passages, designed to keep the pressure on the outside of the eardrum equal to that within the semi-enclosed middle ear. During a cold, infection can spread up into the Eustachian tubes and cause earaches.
And at the lower end of the upper respiratory system, just below the pharynx, is the larynx, or voice box, a valve that controls the passage of air. A pair of cordlike ligaments stretching across this valve vibrate to create the voice. Mucous membrane extends from the nose and pharynx over the larynx walls. Inflammation of this membrane produces the hoarseness or loss of voice that accompanies some colds. This is important when the stages of common cold developing becomes a concern. | Twitter About The Common Cold Cure  | | Common Cold Tip Of The Day Colds are rather difficult to catch by way of the mouth. University of Wisconsin researchers tested couples, asking that in each couple, the cold-stricken partner kiss the unaffiliated one for 90 seconds. Only one caught cold. |
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