American Medical Association Family Medical Guide - American Medical Association [479]
The remaining food that has not been digested then moves into the colon (the longest section of the large intestine), which absorbs water and a small amount of calcium from the undigested food. Bacteria that are normally present in the colon produce important nutrients for the body; other bacteria digest carbohydrates and starches not absorbed by the small intestine. The rectum, which forms the end of the large intestine, collects the partly solid waste (stool) before it is eliminated from the body through the anus.
Disorders of the Mouth and Tongue
The inside of your mouth is covered with a delicate lining of mucous membrane that is kept moist and lubricated by saliva. Saliva is produced in small glands lining the entire mouth and throat and in three pairs of salivary glands—in the floor of the mouth (the sublingual glands), on each side of the neck below the jaw (the submandibular glands), and above each angle of the jaw (the parotid glands). Your tongue has a complex system of muscles that enables it to move food around as you chew and to mold the food into a ball called a bolus that is small enough to be swallowed. The surface of the tongue is covered with hairlike projections called papillae (known as taste buds). All tongues have creases, but some tongues are more deeply fissured than others. Disorders of the mouth include problems with the lining of the mouth, lips, tongue, and gums.
The surface of the tongue
The tongue is muscular and flexible and is covered by many projections called papillae (taste buds).
Canker Sores
Canker sores (also called aphthous ulcers or recurrent aphthous stomatitis) are common, noncontagious sores that can develop in the lining of the mouth (and sometimes on the tongue and gums), exposing the sensitive tissue underneath. Canker sores tend to occur when stress, fatigue, or illness has weakened the immune system. The sores occur most frequently in adolescents and young adults and in women just before a menstrual period. Sores can also occur in the mouth as a result of injuries from a toothbrush, a poorly fitting denture, or a jagged tooth, or from biting the inside of the cheek.
Symptoms
You may not know you have a canker sore until you eat something spicy or acidic, which makes the sore sting. Most canker sores are small (up to ¼ inch in diameter), pale yellow spots surrounded by red borders (see page 126). They usually occur singly but may develop in clusters. (Ulcers from an injury are usually large, single sores.) See your doctor about any sore or swelling in your mouth that recurs or that doesn’t heal within 2 weeks.
Diagnosis
A doctor usually can diagnose canker sores by the symptoms and their appearance. If the sores persist for more than 10 days, he or she may recommend blood tests and a biopsy (in which samples of cells are taken from the sore and examined under a microscope). It is important to make sure that the sores are canker sores and not a sign of a more serious disease such as inflammatory bowel disease (see page 764) or cancer.
Treatment
Canker sores usually heal without treatment. Over-the-counter medications in the form of gels or lozenges are available that relieve pain and protect the exposed tissue until it heals. Avoid very hot, spicy, or acidic food or drinks. Your doctor may prescribe a mouthwash or ointment containing a corticosteroid, or a short course of oral corticosteroids to reduce inflammation.
Cold Sores
Cold sores are blisters in and around the mouth usually caused by the herpes simplex virus. The initial viral infection often occurs during childhood, with severe symptoms such as swollen gums, extreme fatigue, and fever. After the infection clears up, the virus lies dormant indefinitely. Later, another infection (usually a cold), stress, fatigue, sun exposure, or hormonal