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Medical Dictionary - Letter: l



TermDefinitionPronunciation
Lliter
L&Dlabor and delivery
L&Rleft & right
lablaboratory
labi/olips, labia
labialPertaining to the lips.
labial mucosaThe inner lining of the lips.lā'bē-ăl myū-kō'să
-labileunstable, subject to change
laborThe childbirth process of expulsion of the fetus and placenta from the uterus.
labrumA lip.
labyrinthA complex system of ducts and cavities that comprise the organs of hearing and balance.
labyrinth/oinner ear
labyrinthectomyAn ear operation used for Meniere's syndrome.lab´ĭ-rin-thek´to-me
labyrinthitisInflammation of the inner ear (labyrinth).
lacerationA wound, specifically a deep tear or cut of the flesh.las″ĕ-ra´shun
lacrim/otears
lacrimationCrying.
lact/omilk
lactaseAn enzyme secreted by the small intestine glands that convert lactose into glucose and galactose.
lactationProduction of milk by the mammary glands.
lacti-milk
lactic acidA organic acid produced by anaerobic respiration, by fermentation of carbohydrates in the rumen and by bacterial action on milk.
lactoseThe main sugar of milk consisting of one molecule each of glucose and galactose.
lacunaA small cavity or depression.
LADleft anterior decending
lal/ospeech
lamellaA thin scale or plate, as of bone.
lamin/olamina (part of the vertebral arch that forms the roof of the spinal canal)
laminectomyA surgical procedure to remove a portion of the vertebral bone called the lamina.lam″ĭ-nek´to-me
lampr/oclear
lancetA two-edged surgical knife with a sharp point.
lanolinWool fat that is refined and used as an emollient, cosmetic, and pharmaceutic aid.
lapar/oabdominal wall
laparoscopeAn endoscope for examining the abdominal and pelvic organs in the peritoneal cavity.
laparoscopySurgery using a thin light tube inserted into a small incision. lap″ah-ros´kah-pe
laparotomyIncision into the side of the abdomen between the ribs and pelvis.
larvaWormlike developmental stage in the life cycle of insects, worms, and other metamorphosing animals.
laryng/olarynx
laryngectomyPartial or total removal of the larynx. lar″in-jek´to-me
laryngitisInflammation of the larynx, including the vocal cords. Characterized by voice disorders, usually viral etiology.lar″in-ji´tis
laryngomalaciaAn abnormally underdeveloped or degenerated cartilage in the larynx.
laryngoplastyPlastic repair of the larynx.
laryngoscopyVisual examination of the larynx. May also include treatment. lar″ing-gos´kah-pe
larynxThe voice box. Includes the vocal cords and surrounding cartilage. lar´ingks
laser trabeculoplastyUsing a very focused beam of light to treat the drainage angle of the eye. trah-bek´u-lo-plas″te
latlateral
later/oside
lateralAway from the body's midline
lavageWashing out a body cavity with water or medicated solution.
laxativeAgents that produce a soft formed stool and relax the bowels, used to relieve constipation.
lbpound
LBBBleft bundle branch block
LBWlow birth weight
LDHlactate dehydrogenase
LDLlow-density lipoprotein
LElower extremity
lecith/oyolk, ovum
leechingThe application of leeches to the body to draw blood for therapeutic purposes.
legThe inferior part of the lower extremity between the knee and the ankle. Common usage is the entire lower limb.
-legiareading
legionnaires diseaseAn acute bacterial infection of the lungs characterized by high fever, malaise, muscle aches, respiratory disorders and headache.
lei/osmooth
leiomy/osmooth (visceral) muscle
leiomyomaA benign neoplasm derived from smooth muscle tissue, also known as a fibroid tumor. They usually occur in the uterus.
leiomyosarcomaA malignant neoplasm derived from smooth muscle.
leishmaniasis A group of infections, caused by the protozoan flagellate Leishmania.
-lemmasheath, confining membrane
lentigoA small, flat, pigmented spot on the skin.
lepid/oflakes, scales
leprosyChronic bacterial infection that affects peripheral nerves in the hands and feet, mucous membranes of the nose, throat and eyes and that causes skin lesions.
-lepsisseizure
-lepsyseizure
lept-thin, slight, slender
leptinA hormone that regulates energy balance by helping control appetite.lep'tin
lesionAny abnormal changes or damage to body tissues.le´zhun
lethargyA condition of tiredness, fatigue, or lack of energy.leth´er-je
leuk/owhite
leukemiaCancer of the blood. The bone marrow then produces abnormal white blood cells which do not function properly.loo-ke´me-ah
leukocyt/owhite blood cell
leukocyteA white blood cell.
leukocytosisAn abnormally large increase in the number of leukocytes in the blood.
leukoplakiaA white patch lesion found on a mucous membrane that cannot be scraped off.loo″ko-pla´ke-ah
leukorrheaNormal vaginal discharge during pregnancy . It is thin, white, milky and mild smelling.loo″ko-re´ah
levo-left
levocardiaCongenital abnormalities in which the heart is in the normal position in the left side of the chest but some or all of the thorax or abdomen viscera are transposed laterally.
-lexiareading, word
LFTliver function test
LGIlower gastrointestinal
LHluteinizing hormone
Lilithium
libidoSexual desire.
lichenAny of various papular skin disease in which the lesions are typically small, firm papules set very close together.
lidocaineA local anesthetic, analgesic and cardiac depressant.
lien/ospleen
LIFleukemia inhibatory factor
ligligament
ligamentFlexible, tough bands of fibrous tissue connecting bones at a joint.
limbicEdge.
lingu/otongue
lingualPertaining to or near the tongue.
linimentsHeat-generating liquids that are applied to the skin.
lip/ofat, lipid
lipedemaA chronic disease that occurs mostly in females. It is characterized by bilateral, symmetrical fatty tissue excess, mainly in the legs.lip″ĕ-de´mah
lipidOrganic compounds, including the fats, oils, waxes, sterols, and triglycerides, that are insoluble in water but soluble in nonpolar organic solvents.
lipolysisThe metabolic process of breaking down of fat.
lipomaA noncancerous growth of fatty tissue cells. Occurs over area of past trauma.lĭ-po´mah
lipomatosisA disorder characterized by abnormal tumor-like accumulations of fat in body tissues.
liposarcomaA malignant neoplasm of fat cells that occurs in the retroperitoneal tissues and the thigh.
liposuctionPlastic surgery that removes subcutaneous fat using a suction tube.
-lipsisomit, fail
liq.liquid; fluid
-listhesisslipping
lith/ostone, calcification
lithiasisFormation of stones in an internal organ, such as in the gallbladder, kidney, and lower urinary tract.
-lithiasispresence of stones
-lithotomyincision for stone removal
liverA large lobed glandular organ in the abdomen with a wide range of function including detoxification, metabolism, synthesis and storage of various substances.
LLEleft lower extremity
LLLleft lower lobe
LLQleft lower quadrant
lmplast menstrual period
lob/olobe
lobeA major division of an organ.
LOClevel/loss of consciousness
loc-place
lochiaA vaginal discharge occurring during the first week or two after childbirth.
locomotionMovement or the ability to move from one place or another.
locusA place or site.
-logspeech, words, thought
log-speech, words
logad/owhites of the eyes
-logistspecialist
logo-words, speech
-logystudy of
loinThe part of the side and back between the lowest rib and the pelvis.
longevityAn organism's life span.
longitudinal studiesStudies in which variables relating to an individual or group of individuals are assessed over an extended span of time.
loph/oridge, crested part
lord/ocurve, swayback
lordosisAbnormal, concave curvature of the lower spine. Also called swayback. lor-do´sis
lot.lotion
loupeA magnifying lens.
low density lipoproteinCholesterol that collects on blood vessel walls, increasing risk of heart problems.lip'ō-prō'tēn
lox/ooblique, slanting
lozengeA medicated candy.
LPlumbar puncture
LRlactated ringer (solution)
LRIlower respiratory infection
LRTlower respiratory tract
lubricationThe use of an agent such as grease to diminish friction between two surfaces.
luc/ilight
-lucentlight admitting
LUEleft upper extremity
LULleft upper lobe
lumb/olower back
lumbagoMild to severe low back pain.lum-ba´go
lumbarReferring to the lower back below the thoracic vertebrae and above the sacral vertebrae.
lumenThe channel within a tube or tubular organ.
lumin/olumen (channel within a tube)
luminescenceEmission of light from a body as a result of a chemical reaction.
lumpectomy Surgical excision of a tumor from the breast without removing large amounts of surrounding tissue.
lungsA pair of organs that aerate the blood. The right lung is divided into three lobs while the left lung has two lobes.
lupusAny of a group of inflammatory autoimmune disorders can affect the skin, joints and internal organs.
LUQleft upper quadrant
luteinizing hormoneA hormone released by the pituitary gland. It stimulates the secretion of sex hormones by the ovary and the testes and is involved in the maturation of spermatozoa and ova.lū'tē-ĭ-nīz-ing
luteomaAn ovarian neoplasm composed of luteal cells derived from luteinized granulosa cells and theca cells.
LVleft ventricle
LVADleft ventricular assist device
LVHleft ventricular hypertrophy
lyme diseaseAn subacute inflammatory disorder caused by a spirochete, Borrelia burgdorferi, which is transmitted chiefly by ticks. It is characterized by fatigue, concentration difficulties or joint pain.
lymphThe interstitial fluid that is in the lymphatic system. limf
lymph/olymph
lymphaden/olymph node
lymphadenitisInflammation of the lymph nodes.lim″fad-ĕ-ni´tis
lymphadenopathyInflammation of the lymph nodes causing enlargement.lim-fad″ĕ-nop´ah-the
lymphangi/olymph vessel
lymphangiectasisA transient dilatation of the lymphatic vessels.
lymphangiomaA congenital malformation of the lymphatic system. lim-fan″je-o´mah
lymphangiosarcomaA malignant neoplasm originating from the endothelial cells of lymphatic vessels.
lymphedemaEdema due to obstruction of lymph vessels or disorders of the lymph nodes. A common complication in the arms after mastectomy.lim″fĕ-de´mah
lymphoceleCystic mass containing lymph.
lymphocytesWhite blood cells that help determine the body's immune response to infectious microorganisms.lim´fo-sītz
lymphocytosisAn abnormal increase in the number of lymphocytes in the blood.
lymphomaA cancer of the lymphatic system.lim-fo´mah
lymphopeniaDecrease in the number of lymphocytes of the blood.
lymphuriaThe presence of lymph in urine.
lysineAn essential amino acid.
-lysisloosening, separating
lyso-dissolution, loosen