luteinizing hormone A gonadotropin (a hormone that affects the function of the sex organs) that is released by the pituitary gland in response to luteinizing hormone-releasing hormone. Abbreviated LH. In females, LH controls the length and sequence of the female menstrual cycle, including ovulation, preparation of the uterus for implantation of a fertilized egg, and…
Luschka, foramina of See foramina of Luschka.
LUQ Left upper quadrant (quarter). For example, the LUQ of the abdomen contains the spleen.
lupus erythematosis, systemic A form of lupus that has a tendency to involve the internal organs. Abbreviated SLE. Eleven criteria have been established for the diagnosis of SLE, including the presence of a malar (“butterfly”) rash and/or other discoid skin rash; skin rash in reaction to sunlight exposure; ulceration of the mucus lining of the…
lupus, discoid A chronic inflammatory condition that is limited to the skin and is caused by an autoimmune disease. Up to 10 percent of persons with discoid lupus eventually develop systemic lupus erythematosus (SLE). Heredity, viruses, ultraviolet light, and drugs may also be involved. Skin symptoms associated with discoid lupus include patchy redness with areas…
lupus A chronic inflammatory disease that is caused by autoimmunity. Patients with lupus have in their blood unusual antibodies that are targeted against their own body tissues. Lupus can cause disease of the skin, heart, lungs, kidneys, joints, and nervous system. The first symptom is a red (or dark), scaly rash on the nose and…
lung transplant Surgery to replace a diseased or damaged lung with a healthy lung from an organ donor. Lung transplant is sometimes done in tandem with heart transplant. See also transplant.
lung, collapsed See atelectasis.
lung One of a pair of three-lobed breathing organs located within the right and left sides of the chest. The lungs remove carbon dioxide from the blood and bring oxygen into the blood. Air comes into the lungs via the trachea, traveling evenly into the left and right lungs by means of the left and…
lumpectomy The surgical removal of a small tumor, which may be benign or cancerous. In common use, lumpectomy refers especially to removal of a lump from the breast. Lumpectomy, often with chemotherapy or radiation therapy, can be an alternative to mastectomy in cases of nonmetastatic breast cancer.
lumbar vertebrae The five vertebrae situated between the thoracic vertebrae and the sacral vertebrae in the spinal column. The lumbar vertebrae are represented by the symbols L1 through L5.
lumbar puncture A procedure in which cerebrospinal fluid is removed from the spinal canal for diagnostic testing or treatment. Abbreviated LP. The patient usually lies sideways for the procedure, although LPs in infants are often done upright. After local anesthesia is injected into the small of the back (the lumbar area), a needle is inserted…