caesarean section A procedure in which an infant is surgically removed from the uterus rather than being born vaginally. Caesarean sections were performed in ancient civilizations to salvage babies upon the death of nearly full-term pregnant women. Julius Caesar is said to have been born by this procedure, hence the name. The term section in…
bubonic plague An infectious disease that is caused by the bacterium Yersinia pestis and is transmitted to humans from infected rats by the oriental rat flea. It is named for the characteristic feature of buboes (painfully enlarged lymph nodes) in the groin, armpits, neck, and elsewhere. Other symptoms of bubonic plague include headache, fever, chills,…
buccal mucosa The inner lining of the cheeks and lips.
bulbourethral gland A pea-sized gland in the male located behind and to the side of the urethra that discharges a component of seminal fluid into the urethra. There are two bulbourethral glands, one on each side. Also known as the Cowper’s gland.
bulimia An eating disorder characterized by periods of extreme overeating, often interrupted by periods of anorexia. Bulimia is usually accompanied by self-induced vomiting or other forms of purging, including the use of laxatives, obsessive exercise, or fasting. Bulimia can be life-threatening due to dehydration, and it can cause permanent damage to the bowels, liver, kidney,…
Bulimia, or bulimia nervosa, is an eating disorder characterized by episodes of binge eating followed by attempts to prevent weight gain through unhealthy behaviors such as vomiting (purging), excessive exercise, or the misuse of laxatives or diuretics. Individuals with bulimia may feel a lack of control during binge episodes, leading to feelings of guilt, shame,…
bullous Characterized by blistering, such as a second-degree burn.
bullous pemphiguoid A disease characterized by tense, blistering eruptions of the skin caused by inflammation associated with antibodies in the basement membrane layer of skin. It is diagnosed by skin biopsy showing the abnormal antibodies deposited in the skin layer. Treatment is with topical cortisone creams but sometimes requires high doses of cortisone (steroids) or…
bump A raised area resulting from blood and serum leaking from injured blood vessels into the tissues, as well as from the body’s inflammatory response to the injury. A purplish, flat bruise that occurs when blood leaks out into the top layers of skin is referred to as an ecchymosis.
BUN Blood urea nitrogen.
bunion A localized, painful swelling at the base of the big toe due to new bone formation. The affected toe is often curved outward. Bunions are frequently associated with inflammation of the nearby bursa (bursitis) and degenerative joint disease (osteoarthritis). Bunions most commonly affect women, particularly those who wear tight-fitting shoes and high heels. Treatment…
Burkitt lymphoma A type of non-Hodgkin lymphoma that most often occurs in young people between the ages of 12 and 30. Burkitt lymphoma usually causes a rapidly growing tumor in the abdomen and, less often, tumors in the testis, sinuses, bone, lymph nodes, skin, bone marrow, or central nervous system. Burkitt lymphoma is a tumor…