Dictionary

laxative Something that promotes emptying of the bowels. Laxatives are used to combat constipation. They are sometimes overused, producing diarrhea. Laxatives include milk of magnesia and many others.

law, Hardy-Weinberg See Hardy-Weinberg law.

lavage Washing out. Gastric lavage, for example, is the washing out of the stomach to remove drugs or poisons.

laughing gas See nitrous oxide.

latex allergy An allergic reaction to the protein found in rubber latex. Latex is made from a natural product of tropical rubber trees and is found in surgical gloves, balloons, condoms, rubber bands, pacifiers, and many other products. The allergic reaction can be mild, consisting of bumps or a rash on the skin in areas…

lateral X-ray An X-ray taken from the side of the patient.

lateral ventricle A communicating cavity in the brain that is part of a system of four communicating cavities that are continuous with the central canal of the spinal cord. The two lateral ventricles are located in the cerebral hemispheres, one in each hemisphere. Each consists of a triangular central body and four horns. The third…

lateral meniscus of the knee A thickened crescent-shaped cartilage pad in the outer portion of the joint formed by the femur (thigh bone) and the tibia (shin bone). The lateral meniscus acts as a smooth surface for the joint to move on. The lateral meniscus is toward the outer side of the knee joint. It…

lateral collateral ligament of the knee The ligament that straps the outside of the knee joint. It helps provide stability and strength to the knee. See also knee.

LASIK Laser-assisted in situ keratomileusis, a kind of laser eye surgery that is designed to change the shape of the cornea to correct vision defects including nearsightedness (myopia), farsightedness (hyperopia), and astigmatism. LASIK is an outpatient procedure that is done with numbing eye drops and takes only minutes to perform. LASIK is similar to photorefractive…

laser surgery, Yag The use of a laser to punch a hole in the iris, in order to relieve increased pressure within the eye. Yag laser surgery is an outpatient procedure that may be used, for example, to treat acute angle-closure glaucoma.

laser A powerful beam of light that is used in some types of surgery to cut or destroy tissue.