Glossary Index by Letter

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The luteinizing hormone. A gonadotropin secreted by the pituitary gland, the hormone promotes masculinity in men and helps to regulate the menstrual cycle in women in conjunction with FSH.


The Luteinizing Hormone Releasing Hormone; another name for GnRH. Luteinizing hormone-releasing hormone - Decapeptide hormone released by the hypothalamus which stimulates the synthesis and secretion of both follicle stimulating hormone (FSH) and luteinizing hormone...


Leukemia inhibiting factor. Affects many systems, including hematopoietic, embryonic, bone, hepatic, neuronal, and fat tissues.


In the area of the tumor; confined to one specific area. Localization - The process of determining or marking the location or site of a lesion or disease. May also refer to the process of keeping a lesion or disease in a specific location or site.

Lumbar Puncture

Spinal tap. Needle penetration into the subarachnoid space of the lumbar spine. Used to withdraw a sample of spinal fluid for examination. Also used to inject a dye into the spine prior to a myelogram.

Lumen, Pl. Lumina, Lumens

The space in the interior of a tubular structure, such as an artery or the intestine. The build-up of plaque in the internal carotid artery can lead to narrowing of the artery's lumen, preventing sufficient blood flow to the brain.


A clear, transparent, sometimes faintly yellow and slightly opalescent fluid that is collected from the tissues throughout the body Lymph flows in the lymphatic vessels (through the lymph nodes), and is eventually added to the venous blood circulation. Lymph consists...

Magnetic Resonance Imaging (MRI)

MRI is a scanning device that uses a magnetic field, radio waves, and a computer. Signals emitted by normal and diseased tissue during the scan are assembled into an image


In reference to an abnormal tissue growth neoplasm (cancer), having the property of locally invasive and destructive growth and metastasis (spreading). Semantics prevail. For example, invasive pituitary tumors are not thought to be malignant.


Imaging examination of the breast by means of x-rays Used for screening and diagnosis of breast disease. Ultrasound and magnetic resonance may also be used to image the breast.

Mass Effect

Damage to the brain due to the bulk of a tumor, the blockage of fluid, or excess accumulation of fluid within the skull. Damage to the brain due to the bulk of a tumor, the blockage of fluid, or excess accumulation of fluid within the skull.


The word medial comes from the Latin medialis, from medius, meaning the middle. Medial is the adjective corresponding to the noun median, as in the median in a highway. Pertaining to the middle; in or toward the middle; nearer the middle of the body. Medial is as...

Median Survival

Median means the middle value. An equal number of people live longer as die earlier than the median.

Medroxyprogesterone Actetate

A semi-synthetic medication which is close in structure and function to the naturally occurring female sex hormone, progesterone. A synthetic steroid progestational hormone that is used especially in the treatment of amenorrhea and abnormal uterine bleeding, in...


Thin layer of tissue covering a surface, lining a body cavity, or dividing a space or organ. Pericarditis is a condition in which the membrane, or sac, around your heart is inflamed.

Meninges, Plural of Meninx

Any membrane; specifically, one of the membranous coverings of the brain and spinal cord. The brain and spinal cord are covered by 3 connective tissue layers collectively called the meninges that consist of the pia mater, the arachnoid and the dura mater. The meninges...


The spread of a disease process from one part of the body to another. The appearance of abnormal tissue growths (malignant or nonmalignant) in parts of the body remote from the site of the primary tumor.


Using an operating microscope to better visualize a small operating field or perform delicate surgery. The examination of minute objects by means of a microscope, an instrument which provides an enlarged image of an object not visible with the naked eye.

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