laminectomy

laminectomy A surgical procedure in which the posterior arch of a vertebra is removed. Laminectomy is done to relieve pressure on the spinal cord or on the nerve roots that emerge from the spinal canal. The procedure may be used to treat a slipped or herniated disc or to treat spinal stenosis.

lactose intolerance

lactose intolerance The inability to digest lactose, a component of milk and some other dairy products. The basis for lactose intolerance is the lack of an enzyme called lactase in the small intestine. The most common symptoms of lactose intolerance are diarrhea, bloating, and gas. The diagnosis may be made via a trial of a…

Lactobacillus

Lactobacillus A bacterium normally found in the mouth, intestinal tract, and vagina. Lactobacillus can also live in fermenting products, such as yogurt. Humans appear to have a symbiotic relationship with this bacteria: some types have become an important part of food digestion, although Lactobacillus can also contribute to cavities in the teeth if allowed to…

lactic acid

lactic acid A simple sugar that is the byproduct of glucose metabolism. Most lactic acid is produced by the red blood cells and by muscle cells when oxygen levels are low. When lactic acid accumulates rapidly in the muscle cells during or just after exercise, cramping can result. When lactic acid builds up faster than…

lactation

lactation The process of milk production. Human milk is secreted by the mammary glands, which are located within the fatty tissue of the breast. The hormone oxytocin is produced in response to the birth of a new baby, and it both stimulates uterine contractions and begins the lactation process. For the first few hours of…