Medical Terminology
Glossary
ileocecal sphincter - a fold of mucous membrane that guards the opening from the ileum into the large intestine; also called ileocecal valve
ileum - the terminal portion of the small intestine
immunity - state of being resistant to injury, particularly by poisons, foreign proteins, and invading parasites, due to the presence of antibodies
immunogenicity - the ability of an antigen to stimulate antibody production
immunoglobulin (Ig) - an antibody synthesized by plasma cells (derived from B lymphocytes) in response to the introduction of antigen; immunoglobulins are divided into 5 kinds (IgG, IgM, IgA, IgD, IgE), based primarily on the larger protein component present in the immunoglobulin
immunology - a branch of science dealing with the responses of the body when it is challenged by antigens
immunosuppression - inhibition of the immune response
immunotherapy - an attempt to induce the immune system to mount an attack against cancer cells by administration of antibodies or nonspecific immune stimulants
imperforate - abnormally closed
impetigo - a contagious skin disorder characterized by pustular eruptions
implantation - insertion of a tissue or a part into the body; attachment of the blastocyst to the lining of the uterus 7-8 days after fertilization
impotence - weakness; inability to copulate; failure to maintain an erection long enough for sexual intercourse
in utero - within the uterus
in vitro - literally, in glass; outside the living body and in an artificial environment such as a laboratory test tube
in vivo - in the living body
incontinence - inability to retain urine, semen, or feces, through loss of sphincter control
infarction - the presence of a localized area of necrotic tissue, produced by inadequate oxygenation of the tissue
infection - invasion and multiplication of microorganisms in body tissues; may be inapparent or be characterized by cellular injury
infectious mononucleosis - contagious disease caused by the Epstein-Barr virus (EBV) and characterized by elevated mononucleocyte and lymphocyte counts, fever, sore throat, stiff neck, cough, and malaise
inferior vena cava (IVC) - the large vein that collects blood from those parts of the body inferior to the heart and returns it to the right atrium
inflammation - a localized, protective response to tissue injury designed to destroy, dilute, or wall off the infecting agent or injured tissue; characterized by redness, pain, heat, swelling, and occasional loss of function
inflammatory bowel d. - 1) Crohn's disease (GI tract inflammation, especially the distal ileum/proximal colon, which may extend from the mucosa through the serosa) or 2) ulcerative colitis (GI tract inflammation, usually limited to the large intestine and accompanied by rectal bleeding)
infraspinous - below a spine; specifically the fossa located beneath the scapular spine
infundibulum - the stalk-like structure that attaches the pituitary gland (hypophysis) to the hypothalamus of the brain; the funnel-shaped, open, distal end of the uterine (Fallopian) tube
ingestion - taking in of food, liquids, or drugs, by mouth
inguinal - pertaining to the groin
inorganic compound - any compound that usually lacks carbon, is usually small, and contains ionic bonds; examples include water as well as many acids, bases, and salts
insertion - manner or place of attachment of a muscle to the bone(s) that it moves
insomnia - difficulty falling asleep as well as, usually, frequent awakening
inspiration - the act of drawing air into the lungs
insula - triangular area of cerebral cortex that lies deep within the lateral cerebral fissure, under the parietal, frontal, & temporal lobes: it cannot be seen in an external view of the brain; also called the island or isle of Reil
insulin - a hormone produced by the beta cells of the pancreas; it decreases the blood glucose level
integrin - the receptor on a plasma membrane that interacts with an adhesion protein found in intercellular material and in blood
integumentary - relating to the skin
intercalated disc - irregular transverse thickening of sarcolemma that contains: 1) desmosomes holding the cardiac muscle fibers (cells) together and 2) gap junctions that aid in the conduction of muscle action potentials
intercostal nerve - a nerve supplying a muscle located between the ribs
interferon (IFN) - one of the proteins (alpha, beta, gamma), naturally produced by virus-infected cells; it induces uninfected cells to synthesize antiviral proteins that inhibit intracellular viral replication in uninfected cells; synthesized artificially via recombinant DNA methods
interphase - the period of the cell's life cycle during which all processes except division are occuring; period between two mitotic divisions; also called metabolic phase
interstitial endocrinocyte - cell located in the connective tissue between semi-niferous tubules in mature testis; secretes testosterone; also called an interstitial cell of Leydig
interventricular foramen - the narrow, oval opening through which the lateral ventricles of the brain commmunicate with the third ventricle; also called the foramen of Monro
intervertebral disc - the pad of fibrocartilage located between the bodies of two adjacent vertebrae
intracellular fluid (ICF) - fluid located within cells
intrafusal fibers - three to ten specialized muscle fibers (cells), enclosed partly by a connective tissue capsule that is filled with lymph; these fibers compose the muscle spindles
intramembranous ossif.... - method of bone formation in which bone is formed directly in membranous tissue
intraocular pressure (IOP) - the pressure in the eyeball, produced mainly by aqueous humor
intrinsic - of internal origin; e.g., the intrinsic factor, a muco-protein that is formed by gastric mucosa and is necessary for the absorption of vitamin B12
intron - region of DNA that does not code for the synthesis of a protein
intubation - insertion of a tube through the nose or mouth into the larynx and trachea to allow entrance of air or to dilate a stricture
intussesception - the infolding (invagination) of one part of the intestine within another segment
invagination - an infolding of the wall of a cavity into the cavity itself
inversion - the movement of the sole inward at the ankle joint
ion - a charged particle or group of particles; formed usually when a substance, such as salt, dissolves and dissociates
ipsilateral - on the same side; affecting the same side of the body
irritable bowel syndrome - stress-induced disease of the GI tract; cramping and pain accompany alternating diarrhea and constipation; stool may contain excess mucus; flatulence, nausea, and loss of appetite may occur; also called irritable colon or spastic colon
ischemia - the lack of sufficient blood to a part due to obstruction of circulation
isotonic - having equal tension or tone; having equal osmotic pressure between two different solutions or two elements in a solution
isotope - chemical element that has the same atomic number as another but has a different atomic weight; radioactive isotopes change into other elements with emission of certain types of radiation
isovolumetric contraction - the period of time, about 0.05 sec, between the start of ventricular systole and opening of the semilunar valves; there is ventricular contraction, but no emptying, & there is a rapid rise in ventricular pressure
isthmus - a narrow strip of tissue or narrow passage connecting two larger parts
