Gastroenterology

Gastroenterology, medical specialty that focuses on the human digestive system and the diseases that affect it. Specialists in the field, called gastroenterologists, study and treat disorders of the esophagus, stomach, small and large intestines, and colon—collectively called the gastrointestinal tract—as well as disorders of the liver, gallbladder, and other organs involved in digestion.

Among the most common conditions that gastroenterologists care for are disorders of the stomach, the organ that receives, stores, and partially digests food in the early steps of human digestion. Gastritis, for example, is an inflammation of the stomach lining that often results in abdominal pain, nausea, and vomiting. Gastritis may be caused by the bacterium Helicobacter pylori, viral infections, stress, allergies, and reactions to alcohol, aspirin, or other substances. A gastroenterologist must identify the causative agent in order to treat this inflammation.

Gastroenterologists also specialize in treating peptic ulcers, sores or erosions in the lining of the stomach or the first portion of the small intestine, called the duodenum. Superficial ulcers cause indigestion and other pain; ulcers causing deeper erosion may lead to abdominal bleeding and, if untreated, death. In recent years, researchers have found a definitive link between Heliobacter pylori and chronic ulcers. Gastroenterologists prescribe antibiotics that kill this bacterium, as well as medications that buffer the acidity in the stomach or slow the stomach’s secretion of digestive acids.

Gastroenterologists treat many diseases related to other organs involved in digestion. The esophagus, for example, can become inflamed from the presence of gastric acid from the stomach, causing heartburn. This condition, known as acid reflux, may be treated with weight loss, drugs that limit the secretion and acidity of gastric acid, and surgical procedures. In the liver, common disorders include hepatitis, an inflammation caused by infection or toxic agents, and cirrhosis, a condition frequently caused by alcohol damage that can ultimately lead to liver failure. Gastroenterologists also treat gallstones, lumps of solid matter found in the gallbladder; inflammation of the pancreas, called pancreatitis; and inflammation of the colon, called colitis.

Gastroenterologists use a variety of highly specialized tools to examine, diagnose, and treat disorders of the gastrointestinal tract. In a procedure called endoscopy, physicians use a long, flexible tube with magnifying lenses and a light source, called an endoscope, to examine internal body cavities. Endoscopes are fitted with specialized attachments, such as grasping forceps or brushes, that enable the physician to remove small tissue samples for laboratory analysis, in a procedure called a biopsy. Endoscopes are also equipped with lasers that enable gastroenterologists to treat disorders without performing more invasive surgery. For example, gastroenterologists cauterize, or burn, peptic ulcers with laser-equipped endoscopes.

Those seeking a career in gastroenterology must first earn a medical degree, then complete a three-year in-hospital training program called a residency, followed by two years of specialized training in gastroenterology and a certification exam.

Endocrinology

Endocrinology is a branch of medicine dealing with disorders of the endocrine system and its specific secretions called hormones.

Endocrinology is concerned with the study of the biosynthesis, storage, chemistry, and physiological function of hormones and with the cells of the endocrine glands and tissues that secrete them.

For more information about the topic Endocrinology, read the full articles at Wikipedia.org.

Biopsy

Biopsy, surgical removal of living body tissue for study and diagnosis with a microscope. Biopsies are performed on organs to analyze the cause and nature of disease, and on tumors, or abnormal tissue growths, to determine if they are a type of cancer. For patients diagnosed with certain diseases, follow-up biopsies are used to study the effectiveness of a chosen course of medical treatment. Biopsies are vital in diagnosing and monitoring a wide range of illnesses, including muscular dystrophy, characterized by gradual wasting away of skeletal muscle, and Crohn’s disease, the chronic inflammation of the intestines.

An external biopsy specimen is taken by cutting or scraping a piece of tissue from an affected area of skin. When a sample is needed from an area well below the surface of the skin, the procedure is called internal biopsy, and viewing techniques such as ultrasound or computer axial tomography are often used to help the physician guide a hollow needle to the exact location.

In a procedure called aspiration biopsy, a needle is attached to a hypodermic syringe. A tissue sample is collected in the barrel of the syringe by using the suction that is created when the plunger of the syringe is pulled out. In a needle biopsy, the tissue sample is collected by rotating the needle, trapping a small but sufficient amount of tissue within the needle itself. In a punch biopsy, a sharp-edged instrument is used to recover a round piece of tissue from a specific depth below the skin.

Amniocentesis is a form of aspiration biopsy in which a very thin needle is used to remove sample cells from the amniotic fluid that surrounds a fetus in the uterus to study the genetic information they contain. The cell sample is normally taken during the fourth month of pregnancy, and the results reveal the gender of the fetus and also detect genetic abnormalities like Down syndrome.

The endoscope, a cameralike tube with a light, enables physicians to see inside hollow organs like the stomach and bladder, and aids in the procedure of internal biopsy. A tiny knife or scissorslike instrument is attached to the endoscope and is used to cut away sample tissue. By using this form of endoscopic biopsy, the physician can both view and remove the tissue of interest.

Open biopsy is the most invasive of biopsy procedures, involving the surgical opening of a body cavity in order to remove a tissue sample. Once the sample is taken, the surgical procedure is temporarily halted while the suspect tissue is quick-frozen and subjected to microscopic examination. The high magnification of an electron microscope is sometimes used by lab technicians to guarantee a proper diagnosis. If the biopsy confirms the existence of cancer, the completion of the operation may involve the removal of the tumor or even of an entire organ, such as a cancerous lung.

Aerospace Medicine

Aerospace Medicine, branch of preventive medicine that is concerned with the physiological and psychological stresses on the human body in flight. The study of effects within the earth’s atmosphere is also called aviation medicine; beyond this atmosphere the study of effects is also called space medicine. Aerospace medicine was recognized as a subspecialty by the American Medical Association in 1953.

Automation

Automation, system of manufacture designed to extend the capacity of machines to perform certain tasks formerly done by humans, and to control sequences of operations without human intervention. The term automation has also been used to describe nonmanufacturing systems in which programmed or automatic devices can operate independently or nearly independently of human control. In the fields of communications, aviation, and astronautics, for example, such devices as automatic telephone switching equipment, automatic pilots, and automated guidance and control systems are used to perform various operations much faster or better than could be accomplished by humans.