Medical terms - Letter L | MedicalVocabulary.org

L

Abbreviation for liter, a metric measure of capacity that, by definition, is equal to the volume of a kilogram of water at 4 degrees centigrade and at standard atmospheric pressure of 760 millimeters of mercury. >…
L-

Abbreviation for levorotatory, applied to a chemical compound, as in l-dopa. Levorotary is opposed to dextrorotary which is abbreviated as d-. From the Latin laevus, on the left-hand side
L1-L5 (lumbar vertebrae)

The symbols L1 through L5 represent the five lumbar vertebrae. The lumbar vertebrae are situated between the thoracic vertebrae and the sacral vertebrae in the spinal column
La Leche League

An international organization that helps and supports breastfeeding mothers with advice, ideas, and legal and medical advocacy. Founded in 1956 by seven women who had learned about successful breastfeeding while nursing…
La Montagne

See: La Montagne, John
La Montagne, John

(1945-2004) Medical scientist and administrator who helped develop numerous vaccines and made significant contributions to the international effort against emerging and re-emerging infectious diseases. He played a…
LAAM

Levo-alpha acetyl methadol, an alternative to methadone that blocks the effects of opiates for up to 72 hours in the treatment of addiction to heroin and other opiates. See also: Methadone treatment program
Lab

Short for a laboratory (or a Labrador retriever)
Lab result

The result of a test done in a laboratory
Lab test

A test that is done in the laboratory where the appropriate equipment, supplies, and certified expertise are available
Labia

The lips, either the lips around the mouth (the oral labia) or the lip-like external female genitalia (the labia majora and labia minora). See also: Labial; Labrose
Labia majora

The larger (major) outside pair of labia (lips) of the vulva (the female external genitalia).
Labia minora

The smaller (minor) inside pair of labia (lips) of the vulva (the female external genitalia).
Labia, oral

The lips around the mouth. See lip.
Labia, vaginal

The two pairs of labia (lips) at the entrance to the vagina. Together they form part of the vulva, the female external genitalia. See labia majora, labia minora.
Labial

Pertaining to the lip, one of the fleshy folds which surround the opening of the mouth or the vagina. Oral Labia: The upper lip is separated from the nose by the philtrum, the area that lies between the base of the nose…
Labial herpes

Herpes: A small sore situated on the face or in the mouth that causes pain, burning, or itching before bursting and crusting over. The favorite locations are on the lips (the labia), chin or cheeks and in the nostrils…
Labial sounds

The lips are not only anatomic features of note, they are organs of speech essential to certain articulations. A sound requiring the participation of one or both lips is a labial (labium in Latin means lip) sound or…
Labile

Labile: Unstable, unsteady, not fixed. In psychology or psychiatry, labile denotes free and uncontrolled moods or behaviors expressing emotions. In biochemistry, labile means easily removable as, for example, a labile…
Labile diabetes

A type of diabetes when a person's blood glucose (sugar) level often swings quickly from high to low and from low to high. Also called 'unstable diabetes' or 'brittle diabetes.
Lability

The state or quality of being labile: susceptible to change, error or instability. From the Latin labilis meaning prone to slip, from labi meaning to slip. See also: Labile
Labiodental sound

A sound that requires the involvement of the teeth and lips, such as 'v,' which involves the upper teeth and lower lip
Labium

A lip. Labium is the singular of the Latin neuter noun meaning lip. The plural is labia. For more information, see: Labia
Labor

Childbirth, the aptly-named experience of delivering the baby and placenta from the uterus to the vagina to the outside world. There are two stages of labor. During the first stage (called the stage of dilatation), the…
Labor support professional

See: Doula (the first meaning)
Labor, false

Intermittent non-productive muscular contractions of the womb (uterus) during pregnancy, most commonly in the last two months before full term. These contractions are non-productive in the sense that they do not produce…
Laboratory

A place for doing tests and research procedures and preparing chemicals, etc. Although 'laboratory' looks very like the Latin 'laboratorium' (a place to labor, a work place), the word 'laboratory' came from the Latin…
Laboratory, Jackson

The premiere place for mouse genetics and the largest mammalian genetic research facility in the world. Many of the types of mice used in medical research originated at the laboratory which is in Bar Harbor on Mount…
Labra

The plural of labrum, a ring of fibrocartilage (fibrous cartilage) around the edge of the articular (joint) surface of a bone. In Latin, 'labrum' means 'lip.' The term is generally used to designate a lip, edge, or brim.
Labrocyte

A mast cell
Labrose

In medicine, a ring of fibrocartilage (fibrous cartilage) around the edge of the articular (joint) surface of a bone. The term labrum is used in anatomy to designate a lip, edge, or brim. Plural: labra. The glenoid…
Labrum

In medicine, a ring of fibrocartilage (fibrous cartilage) around the edge of the articular (joint) surface of a bone. The term labrum is used in anatomy to designate a lip, edge, or brim. Plural: labra. The glenoid…
Labyrinth

The maze of canals in the inner ear. The labyrinth is the portion of the ear that is responsible for sensing balance. Inflammation of the labyrinth (labyrinthitis) can be accompanied by vertigo
Labyrinthitis

Inflammation of the labyrinth, the system of intercommunicating canals and cavities within the inner ear responsible for sensing balance. Labyrinthitis may be accompanied by the sudden onset of a feeling of vertigo…
LAC encephalitis

LaCrosse encephalitis, one of the main types of encephalitis caused by an arbovirus in the US. An arbovirus is a virus that is arthropod-borne (carried by a mosquito, tick or another kind of arthropod). The arbovirus…
Laceration

A cut. All that is required to care for most cuts is to wash them with soap and water and keep them clean and dry. Putting alcohol, hydrogen peroxide, and iodine onto cuts can delay healing and should be avoided. Seek…
Lacrimal

Pertaining to tears, as in lacrimal gland (tear gland). From the Indo-European dakru meaning a tear (from a weeping eye) which gave rise to the Greek dakry and the Latin lacrima
Lacrimal gland

A small almond-shaped structure that produces tears. The lacrimal gland is located just above the outer corner of the eye. The lacrimal gland is part of the lacrimal apparatus, the system that forms tears, conveys them…
Lacrimation

One of the main types of encephalitis caused by an arbovirus in the US. An arbovirus is a virus that is arthropod-borne (carried by a mosquito, tick or another kind of arthropod). The arbovirus infects and inflames the…
LaCrosse encephalitis

Enzyme that breaks down the milk sugar lactose into glucose and galactose. Persons with a deficiency of lactase in the gut can develop abdominal cramping and diarrhea after ingesting milk products.
Lactase

Enzyme that breaks down the milk sugar lactose into glucose and galactose. Persons with a deficiency of lactase in the gut can develop abdominal cramping and diarrhea after ingesting milk products
Lactase deficiency

(LDH) An enzyme that catalyzes the conversion of lactate to pyruvate. This is an important step in energy production in cells. Many different types of cells in the body contain this enzyme. Some of the organs relatively…
Lactate dehydrogenase

(LDH) An enzyme that catalyzes the conversion of lactate to pyruvate. This is an important step in energy production in cells. Many different types of cells in the body contain this enzyme. Some of the organs relatively…
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…
Lactic acidosis

Acidosis (too much acid in the body) due to the buildup of lactic acid in the body. Lactic acidois occurs when cells make lactic acid (from glucose) faster than it can be metabolized. The key signs of lactic acidosis…
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. Lactobacillus…
Lactobacillus acidophilus

The bacteria found in milk and fermented milk products, particularly yogurt with 'live cultures' of L. acidophilus. L. acidophilus assists with the digestive process within the intestinal tract. It can be decimated by…
Lactose

The sugar found in milk. The body uses the enzyme lactase to break down lactose into galactose and glucose
Lactose intolerance

Lactose intolerance: Inability to digest lactose, a component of milk and most other dairy products. Lactose is sometimes also used as an ingredient in other foods, so those with a lactase deficiency should check labels…
Lacuna

A small pit, cavity, defect or gap