Medical terms - Letter L (page 7) | MedicalVocabulary.org

Lifetime risk

The risk of developing a disease during ones lifetime or dying of the disease. The estimated lifetime risk of developing diabetes for individuals born in 2000 in the US is 32.8% for males and 38.5% for females. Women…
Ligament

A ligament is a tough band of connective tissue that connects various structures such as two bones. 'Ligament' is a fitting term; it comes from the Latin 'ligare' meaning 'to bind or tie.'
Ligament, anterior cruciate

See: Anterior cruciate ligament
Ligament, lateral collateral knee

The knee joint is surrounded by a joint capsule with ligaments strapping the inside and outside of the joint (collateral ligaments) as well as crossing within the joint (cruciate ligaments). These ligaments provide…
Ligament, medial collateral knee

The knee joint is surrounded by a joint capsule with ligaments strapping the inside and outside of the joint (collateral ligaments) as well as crossing within the joint (cruciate ligaments). These ligaments provide…
Ligament, patellar

See: Patellar tendon
Ligament, posterior cruciate

The knee joint is surrounded by a joint capsule with ligaments strapping the inside and outside of the joint (collateral ligaments) as well as crossing within the joint (cruciate ligaments). These ligaments provide…
Ligaments, knee

Ligaments are strong, elastic bands of tissue that connect bone to bone. They provide strength and stability to the joint. Four ligaments connect the femur (the bone in the thigh) with the tibia (the larger bone in the…
Ligand

A molecule that binds to another. Often, a soluble molecule such as a hormone or neurotransmitter that binds to a receptor. From the Latin ligandus, binding from the root ligare, to bind or tie. Ligate and ligature come…
Ligate

To tie or to tie off, as in to ligate an artery. From the Latin 'ligare' meaning 'to bind or tie.' Ligature and ligand come from the same root.
Ligature

In surgery, a filament or thread used to tie something, such a blood vessel to prevent it from bleeding or the pedicle of a tumor to constrict it. Ligatures may be of silk, gut, wire, and other materials. From the Latin…
Lightening

Not to be confused with a discharge of atmospheric electricity, lightening refers to the sensation that a pregnant woman feels when the baby drops. This is the time when the presenting (lowermost) part of the fetus…
Lightheadedness

A feeling you are 'going to faint.' Lightheadedness is medically distinct from dizziness, unsteadiness, and vertigo. See: Dizziness, Unsteadiness, and Vertigo
Lightning injuries

A sensation of flashing lights is created when the vitreous (the clear, jelly-like substance that fills the middle of the eye) shrinks and tugs on the retina. These flashes of light can appear off and on for several…
Lights, flashing

A sensation of flashing lights is created when the vitreous (the clear, jelly-like substance that fills the middle of the eye) shrinks and tugs on the retina. These flashes of light can appear off and on for several…
Lilliputian hallucination

An hallucination in which things, people, or animals seem smaller than they would be in real life. Lilliputian refers to the 'little people' who lived (fictionally) on the island of Lilliput in Jonathan Swift's 1726…
Limb

The arm or leg.
Limb-girdle muscular dystrophy

See: Muscular dystrophy, limb-girdle
Liminal

In neurolgy, at the threshold of perception to a sensory stimulus. In other words, just barely perceptible to the senses. 'Liminal' comes from the Latin noun 'limen' meaning 'threshold.' It makes sense, then, that…
Lindane

An organochlorine pesticide and nerve poison. Also a suspected carcinogen (cancer-causing agent). Although many countries have banned lindane, it is still used in the US for treating head lice and scabies. Also known as…
Lindau-von Hippel syndrome

See Von Hippel-Lindau syndrome
Line, central

A catheter (tube) that is passed through a vein to end up in the thoracic (chest) portion of the vena cava (the large vein returning blood to the heart) or in the right atrium of the heart. Central lines have a number…
Line, central venous

A catheter (tube) that is passed through a vein to end up in the thoracic (chest) portion of the vena cava (the large vein returning blood to the heart) or in the right atrium of the heart. Central venous lines have a…
Line, germ

A sequence of cells, each descended from earlier cells in the lineage, which will develop into new sperm and egg cells for the next generation
Line, single transverse palmar

See: Simian crease
Lineage, cell

See: Cell lineage
Lingelsheimia

A group of bacteria named after W. von Lingelsheim. Now known as Acinetobacter. See: Acinetobacter
Lingual

1. Having to do with the tongue. 2. Next to the tongue. In dentistry, the tooth surface next to the tongue. 3. Toward the tongue. 4. Produced by the tongue as, for example, lingual speech.  From the Latin lingua…
Lingual gyrus

An area in the occipital lobe, the visual processing center in the brain. The lingual gyrus extends to the temporal lobe of the brain. A stroke damaging the lingual gyrus reportedly can cause a loss of dreaming…
Lining, uterine

The inner layer of the uterus (womb); the cells that line the womb; anatomically termed the endometrium. This tissue is normally shed monthly in response to the hormonal changes of the menstrual period.
Linkage

The tendency for genes and other genetic markers to be inherited together because of their location near one another on the same chromosome. A gene is a functional physical unit of heredity that can be passed from…
Linkage analysis

Study aimed at establishing linkage between genes. Today linkage analysis serves as a way of gene-hunting and genetic testing. Linkage is the tendency for genes and other genetic markers to be inherited together because…
Linkage map

A map of the genes on a chromosome based on linkage analysis. A linkage map does not show the physical distances between genes but rather their relative positions, as determined by how often two gene loci are inherited…
Linus Pauling

See: Pauling, Linus
Lip

One of the two fleshy folds which surround the opening of the mouth. The upper lip is separated from the nose by the philtrum, the area that lies between the base of the nose and the pigmented edge (called the…
Lip, cleft

The presence of one or two vertical fissures (clefts) in the upper lip -- cleft lip can be on one side only (unilateral) or on both sides (bilateral) -- resulting from failure of the normal process of fusion of the lip…
Lipectomy, suction-assisted

Another name for liposuction, the surgical removal of fat deposits from specific parts of the body, the most common being the abdomen (the 'tummy'), buttocks ('behind'), hips, thighs and knees, chin, upper arms, back…
Lipid

Another word for 'fat.' (Please see the various meanings of Fat.) A lipid is more formally defined as a substance such as a fat, oil or wax that dissolves in alcohol but not in water. Lipids contain carbon, hydrogen and…
Lipid profile

Pattern of lipids in the blood. (A lipid profile usually includes the total cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides, and the calculated low density lipoprotein (LDL) cholesterol.
Lipid storage diseases

A series of disorders due to inborn errors in lipid metabolism resulting in the abnormal accumulation of lipids in the wrong places (Examples include Gaucher, Fabry and Niemann-Pick diseases and metachromatic…
Lipids

Another word for 'fats.' (Please see the various meanings of Fat.) Lipids can be more formally defined as substances such as a fat, oil or wax that dissolves in alcohol but not in water. Lipids contain carbon, hydrogen…
Lipitor

See: Atorvastatin
Lipodystrophy

A disorder of adipose (fatty) tissue characterized by a selective loss of body fat. Patients with lipodystrophy have a tendency to develop insulin resistance, diabetes, a high triglyceride level (hypertriglyceridemia)…
Lipodystrophy syndrome

A disturbance of lipid (fat) metabolism that involves the partial or total absence of fat and often the abnormal deposition and distribution of fat in the body. There are a number of different lipodystrophy syndromes…
Lipodystrophy, cephalothoracic

A disorder characterized by painless symmetrical diffuse deposits of fat beneath the skin of the neck, upper trunk, arms and legs. The condition is thought to be genetic although its exact mode of inheritance is…
Lipoid nephrosis

The earliest stage of nephrosis (the nephrotic syndrome of childhood). See: Minimal change disease. See also: Nephrosis.
Lipoidosis, sphingomyelin

Also called Niemann-Pick disease, this is a disorder of the metabolism of a lipid (fat) called sphingomyelin that usually causes the progressive development of enlargement of the liver and spleen (hepatosplenomegaly)…
Lipoma

A benign fatty tumor.
Lipomatosis, multiple symmetric

A disorder characterized by painless symmetrical diffuse deposits of fat beneath the skin of the neck, upper trunk, arms and legs. The condition is thought to be genetic although its exact mode of inheritance is…
Lipophilin

See: Proteolipid protein