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L Glossary




Labyrinth - the bony structure of the inner ear. The labyrinth consists of three semicircular canals, the cochlea, and the vestibule. The functions of the labyrinth include both hearing and balance. 





Lactose - sugar found in milk and milk products, which the body breaks down into galactose and glucose.


Lactose tolerance test - a test that determines the body's ability to digest lactose (a sugar found in milk and milk products).

laminectomy - surgical procedure which includes removal of a portion of the lamina to provide more room in the vertebral canal; usually for disc herniation or spinal canal stenosis.

Landau-Kleffner syndrome - a childhood disorder of unknown origin that can be identified by gradual or sudden loss of the ability to understand and use spoken language.







Laparoscopic lymphadenectomy - the removal of pelvic lymph nodes with a laparoscope performed through small incisions in the lower abdominal region.



Large intestine (also called the colon) - part of the intestine that goes from the cecum to the rectum.

Laryngeal neoplasms - abnormal growths in the larynx (voice box) that can be cancerous or non-cancerous.

Laryngeal nodules - non-cancerous, callous-like growths on the inner parts of the vocal folds (vocal cords).


Laryngectomy - surgery to remove part or all of the larynx (voice box).





Laser surgery - a type of surgery using a device that emits a beam of light radiation to cauterize a wound, repair damaged tissue, or cut through tissue.

Lateral collateral ligament (LCL) - the ligament that gives stability to the outer knee.

Lateral epicondylitis (also known as tennis elbow) - pain is caused by damage to the tendons that bend the wrist backward away from the palm.

Lavage - washing or rinsing out a body cavity for diagnostic or therapeutic purposes. For example, ductal lavage involves inserting fluid into a milk duct in the breast, removing the fluid, then examining it in the lab for the presence of cancer cells. Gastric lavage is putting fluid into the stomach through a tube, then pumping it out to remove a toxic substance or blood when there has been bleeding in the stomach.

Laxatives (also called cathartics) - medications to relieve long-term constipation.

Lead poisoning - a condition caused by breathing or swallowing substances that contain lead. Exposure to lead over a long period of time can cause serious health conditions, especially in children. 

Learning disability (LD) - a disorder that affects a person's ability to either interpret what he or she sees and hears, or to link information from different parts of the brain. These limitations are characterized by difficulty in reading, writing, and arithmetic.



Leukapheresis - a procedure to remove white blood cells (leukocytes) from the body.


Leukoplakia - a whitish patch of mucous membrane inside the mouth; it is considered to be a precancerous lesion that can develop into oral cancer .

Leukorrhea - whitish vaginal discharge during pregnancy.

Levator syndrome - a feeling of fullness in the anus and rectum with occasional pain, caused by muscle spasms.


Lewy bodies - tiny protein deposits in the part of the brain associated with movement and memory. They are associated with the development of nervous disorders such as Parkinson's disease and Lewy body dementia.


Lichenification - skin that has thickened.


Lipid - a fatty substance in the blood.


Lipoproteins - transporters of fatty substances in the blood.


Lithotripsy, extracorporeal shock wave (ESWL) - method of breaking up kidney stones, bile stones, and gallstones with a specialized tool and shock waves.



Living will - a legal document that states a person's medical preferences for treatment and resuscitation in the event that person can no longer speak for himself or herself.

LMP - last menstrual period.


Lobectomy - removal of an entire lobe of the lung.

Lobule - a subdivision of a lobe in the breast.




Loop electrosurgical excision procedure (LEEP) - a procedure that uses an electric wire loop and low-energy current to remove abnormal tissue from the cervix.


Lordosis (Also called sway-back.) - an exaggeration of the forward curve of the lower part of the back.

Low blood glucose - a condition that occurs when blood glucose levels are too low.

Low-density lipoprotein (LDL) - a type of cholesterol that can build up in the walls of arteries; the "bad" cholesterol.


Lower esophageal sphincter - muscle between the esophagus and stomach.




Lung volume - the amount of air the lungs hold.


Lyme disease (LD) - a bacterial infection caused by the spirochete Borrelia burgdorferi, a spiral-shaped bacterium that is most commonly transmitted by a tick bite.







Lymphangioma - a lump of entwined lymph and blood vessels that may be found in various locations in the body.



