Copy of `Dorland's Medical Dictionary`

The wordlist doesn't exist anymore, or, the website doesn't exist anymore. On this page you can find a copy of the original information. The information may have been taken offline because it is outdated.

Dorland's Medical Dictionary Category: Health and Medicine > Medical Dictionary Date & country: 31/12/2010, USA Words: 39128

median effective dose
(ED50) a dose that produces the desired effect in half of a population.

median immunizing dose
the dose of vaccine or antigen sufficient to provide immunity in half the test subjects.

median infective dose
(ID50) the amount of pathogenic microorganisms that will produce demonstrable infection in half the test subjects.

median lethal dose
(LD50) the quantity of an agent or of ionizing radiation that will kill half the test subjects or half of any population.

median line
an imaginary vertical line dividing the body equally into right and left parts.

median mandibular point
a craniometric landmark, being the point on the anteroposterior center of the mandibular ridge in the median plane, at the site of former mandibular symphysis.

median nerve
origin, lateral and medial cords of brachial plexus—C6–T1; branches, anterior interosseous nerve of forearm, common palmar digital nerves, muscular and palmar branches, and a communicating branch with the ulnar nerve; distribution, the elbow, wrist, and intercarpal joints, anterior muscles of the forearm, muscles of...

median palatal cyst
one in the midline of the hard palate, between the lateral palatal processes.

median plane
one passing longitudinally through the body, an organ, or a part from front to back, dividing it into right and left halves.

median sacral artery
origin, continuation of abdominal aorta; branches, lowest lumbar artery; distribution, sacrum, coccyx, rectum.

median sacral vein
a vein that follows the median sacral artery and opens into the common iliac vein.

median umbilical ligament
a fibrous cord, the remains of the obliterated umbilical artery, running upward beside the bladder to the umbilicus.

mediastinal
(me″de-әs-ti´nәl) of or pertaining to the mediastinum.

mediastinal emphysema
pneumomediastinum.

mediastinal fibrosis
development of hard white fibrous tissue in the upper portion of the mediastinum, sometimes obstructing the air passages and large blood vessels; called also fibrosing or fibrous mediastinitis.

mediastinal flutter
movement of the tissues and organs of the mediastinum back and forth with each movement of air into and out of an open sucking wound in the thoracic cavity. The condition can produce serious impairment of cardiopulmonary function and is fatal if not treated promptly. Symptoms are similar to those of mediastinal shift.

mediastinal lymphadenitis
mediastinal lymphadenopathy.

mediastinal lymphadenopathy
inflammation and swelling of mediastinal lymph nodes, often caused by some underlying condition such as mediastinitis, a cyst, or a tumor that can be malignant.

mediastinal shift
shifting of the tissues and organs that comprise the mediastinum (heart, great vessels, trachea, and esophagus) to one side of the thoracic cavity, generally because a severe injury to the chest has caused entrapment of air in the pleural cavity (tension pneumothorax). As the volume of air increases on the affected side, the lung col...

mediastinal space
mediastinum.

mediastinal veins
numerous small branches that drain blood from the anterior mediastinum into the brachiocephalic vein, azygos vein, or the superior vena cava.

mediastinitis
(me″de-as″tĭ-ni´tis) inflammation of the mediastinum. fibrosing mediastinitis , fibrous mediastinitis mediastinal fibrosis.

mediastinography
(me″de-as″tĭ-nog´rә-fe) radiography of the structures of the mediastinum.

mediastinopericarditis
(me″de-as″tĭ-no-per″e-kahr-di´tis) inflammation of the mediastinum and pericardium.

mediastinoscope
(me″de-ә-sti´no-skōp) a specially designed endoscope used in mediastinoscopy.

mediastinoscopy
(me″de-as″tĭ-nos´kә-pe) examination of the mediastinum by means of an endoscope inserted through an anterior midline incision just above the thoracic inlet.

mediastinotomy
(me″de-as″tĭ-not´ә-me) incision of the mediastinum.

mediastinum
(me″de-әs-ti´nәm) a median septum or partition. the mass of tissues and organs separating the sternum in front from the vertebral column behind, containing the heart and its large vessels, trachea, esophagus, thymus, lymph nodes, and other structures and tissues. It is divided into anteri...

medicable
(med´ĭ-kә-bәl) subject to treatment with medicine with reasonable expectation of cure.

Medicaid
(med´ĭ-kād) a state-operated program providing medical care to certain low-income persons; the state programs receive federal aid and are subject to federal guidelines.

medical
(med´ĭ-kәl) pertaining to medicine or to the treatment of diseases; pertaining to medicine as opposed to surgery.

medical asepsis
the use of practices aimed at destroying pathological organisms after they leave the body, done in the care of patients with infectious diseases to prevent reinfection of the patient and avoid the spread of infection from one person to another. This is achieved by isolation precautions, in which objects in the patient's e...

medical assistant
a person who, under the direction of a qualified physician, performs a variety of routine administrative and clinical tasks in a physician's office, a hospital, or some other clinical facility.

medical record administrator
one responsible for the indexing, recording, and storage of medical records and reports of patients admitted to hospitals and other health care agencies, and who also prepares reports of births, deaths, transfers, and discharges of patients, and of treatments received.

medical vagotomy
interruption of impulses carried by the vagus nerve by administration of suitable drugs.

MedicAlert
(med″ik-ah-lert´) a necklace or bracelet identifying a medical problem of the wearer and a phone number to call in an emergency. It can be obtained for a small fee from the nonprofit MedicAlert Foundation International, P.O. Box 1009, Turlock, CA 95380.

Medicare
(med´ĭ-kār) a program of the Social Security Administration which provides funding for medical care to the aged and to certain others.

medicated
(med´ĭ-kāt″әd) imbued with a medicinal substance.

medication
(med″ĭ-ka´shәn) medicine (def. 1). impregnation with a medicine. administration of a medicine or other remedy. transdermal medication medication administered using a self-adhesive, premedicated patch applied to the skin. One side of the patch h...

medicinal
(mә-dis´ĭ-nәl) having healing qualities; pertaining to a medicine.

medicine
(med´ĭ-sin) any drug or remedy. the art and science of the diagnosis and treatment of disease and the maintenance of health. the nonsurgical treatment of disease.

medicolegal
(med″ĭ-ko-le´gәl) pertaining to medicine and law, or to forensic medicine.

medicosocial
(med″ĭ-ko-so´shәl) having both medical and social aspects.

medionecrosis
(me″de-o-nә-kro´sis) focal areas of destruction of the elastic tissue and smooth muscle of the tunica media of a blood vessel, especially of the aorta or its major branches.

medionecrosis of aorta
cystic medial necrosis.

mediotarsal
(me″de-o-tahr´sәl) pertaining to the center of the tarsus.

meditation
(med″ĭ-ta´shәn) an intentional and self-regulated focusing of attention, originally used primarily in religious and spiritual practice, whose purpose is to relax and calm the mind and body. mindfulness meditation a technique of meditation in which distracting though...

Mediterranean anemia
(med″ĭ-tĕ-ra´ne-an) thalassemia major.

Mediterranean exanthematous fever
Mediterranean spotted fever boutonneuse fever.

Mediterranean fever
brucellosis. boutonneuse fever.

Mediterranean lymphoma
immunoproliferative small intestine disease.

medium
(me´de-әm) pl. mediums, me´dia an agent by which something is accomplished or an impulse is transmitted. culture medium. a preparation used in treating histologic specimens.

medius
(me´de-әs) Latin word meaning middle; a term used in anatomy.

Medrol
(med´rol) trademark for preparations of methylprednisolone, a steroid antiinflammatory agent.

medroxyprogesterone
(med-rok″sĭ-pro-jes´tĕ-rōn) a progestational agent administered orally as the acetate ester for treatment of secondary amenorrhea and dysfunctional uterine bleeding, for induction of menses, in prevention and treatment of endometrial hyperplasia in postmenopause hormone replacement therapy, and as a test ...

medrysone
(med´rә-sōn″) a synthetic glucocorticoid used topically in treatment of allergic and inflammatory conditions of the eye.

medulla
(mә-dul´ә) the innermost part of a structure or organ. medulla oblongata. marrow. adj., med´ullary., adj.

medulla oblongata
(mә-dul´ә ob″long-ga´tә) a part of the rhombencephalon (hindbrain) that is continuous with the pons above and the spinal cord below. Here the great trunk nerves, both motor and sensory, cross over between left and right, producing the puzzling phenomenon by which the left cerebral hemisphere cont...

medulla of bone
bone marrow.

medulla of thymus
the central portion of each lobule of the thymus; it contains many more reticular cells and far fewer lymphocytes than does the surrounding cortex.

medulla ossium
(m´-dul´ә os´e-´m) bone marrow.

medulla spinalis
(m´-dul´ә spi-na´lis) spinal cord.

medullary
(med´ә-lar″e) (mә-dul´ә-re) pertaining to a medulla. myeloid (def. 1). myeloid (def. 2).

medullary artery
nutrient artery.

medullary canal
spinal canal. marrow cavity.

medullary carcinoma
that composed mainly of epithelial elements with little or no stroma.

medullary cystic disease
medullary cystic kidney disease familial juvenile nephronophthisis. according to some authorities, just one variant of the juvenile nephronophthisis–medullary cystic disease complex, of autosomal dominant inheritance with onset after age 30.

medullary foramen
vertebral foramen.

medullary plate
neural plate.

medullary ray
a cortical extension of a bundle of tubules from a renal pyramid.

medullary respiratory center
the nerve center in the medulla oblongata that coordinates respiratory movements.

medullary sheath
myelin sheath.

medullary space
the central cavity and the intervals between the trabeculae of bone that contain the marrow.

medullary sponge kidney
a usually asymptomatic congenital condition in which many small cystlike dilatations are found in the collecting tubules, so that the kidney is spongy and porous. Called also sponge kidney.

medullary substance
white matter. the soft, marrowlike substance of the interior of such structures as bone, kidney, and adrenal gland.

medullated
(med´ә-lāt″әd) myelinated.

medullated fibers
medullated nerve fibers myelinated fibers.

medullization
(med″ә-lĭ-za´shәn) the enlargement of the haversian canals in rarefying osteitis followed by their conversion into marrow channels; also, the replacement of bone by marrow cells.

medulloadrenal
(mә-dul″o-ә-dre´nәl) adrenomedullary.

medulloblast
(mә-dul´o-blast) an undifferentiated cell of the neural tube that may develop into either a neuroblast or a spongioblast.

medulloblastoma
(mә-dul″o-blas-to´mә) a brain tumor composed of medulloblasts.

medulloepithelioma
(mә-dul″o-ep″ĭ-the″le-o´mә) a brain tumor composed of primitive neuroepithelial cells lining the tubular spaces.

mefenamic acid
(mef″ә-nam´ik) a nonsteroidal antiinflammatory drug used to treat and prevent mild to moderate pain, inflammation, dysmenorrhea, and vascular headache.

mefloquine
(mef´lo-kwin) an antimalarial agent effective against chloroquine-resistant strains of Plasmodium falciparum and P. vivax; used as the hydrochloride salt.

MEFR
maximal expiratory flow rate.

MEG
magnetoencephalography.

megabladder
(meg″ә-blad´әr) megacystis.

megacalicosis
(meg″ә-kal″ĭ-ko´sis) nonobstructive dilatation of the renal calices due to malformation of the renal papillae. Spelled also megacalycosis.

megacaryocyte
(meg″ә-kar´e-o-sīt″) megakaryocyte.

Megace
(mә-gās´) trademark for a preparation of megestrol acetate, a steroid used as a palliative antineoplastic agent and in treatment of anorexia and cachexia.

megacolon
(meg″ә-ko´lәn) dilatation and hypertrophy of the colon. acquired megacolon any type associated with chronic constipation but normal innervation of intestinal ganglion cells. acute megacolon toxic megacolon. aganglionic megac...

megacystis
(meg″ә-sis´tis) an abnormally enlarged urinary bladder; called also megabladder and megalocystis.

megacystis-megaureter syndrome
chronic ureteral dilatation (megaureter) associated with megacystis and gaping of ureteral orifices, permitting vesicoureteral reflux of urine with chronic pyelonephritis.

megaesophagus
(meg″ә-ә-sof´ә-gәs) dilatation and muscular hypertrophy of most of the esophagus, above a constricted, often atrophied, distal segment. See also achalasia.

megahertz
(MHz) (meg´ә-hәrtz) one million (106) hertz.

megakaryoblast
(meg″ә-kar´e-o-blast) the earliest cytologically identifiable precursor in the thrombocytic series, which matures to form the promegakaryocyte.

megakaryoblastic leukemia
acute megakaryocytic leukemia.

megakaryocyte
(meg″ә-kar´e-o-sīt) the giant cell of bone marrow; it is a large cell with a greatly lobulated nucleus, and is generally supposed to give rise to platelets.

megakaryocytic leukemia
hemorrhagic thrombocythemia. acute megakaryocytic leukemia.

megakaryocytopoiesis
(meg″ә-kar″e-o-si´to-poi-e´sis) the production of megakaryocytes.