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Medical Dictionary


bladderworm (blad′er-werm)
SYN: Cysticercus.

bladevent (blad′vent)
A thin, wedge-shaped endosteal implant of metal that is inserted into a surgically prepared groove in the maxilla or mandible.

Sir Charles, British physician, 1748–1820. See B. law.

Henri Marie Ducrotay de, French zoologist and anthropologist, 1777–1850. See B. ears, under ear.

Vilray P., U.S. surgeon, 1871–1955.

Arthur H., U.S. surgeon, 1897–1970. See Sengstaken-B. tube.

Alfred, U.S. surgeon, 1899–1964. See B. shunt, B.-Hanlon operation, B.-Taussig operation, B.-Taussig shunt.

Philippe Frédéric, French anatomist and surgeon, 1798–1849. See B. gland.

A solution consisting of all of the analytical components except the compound to be measured; this is used to establish a baseline of measurement intensity against which the compound of interest is compared. [M.E. white, fr. O.Fr. blanc, fr. Germanic]

A covering. mucus b. the mucous covering of respiratory epithelium.

Term invented by van Helmont to denote a mystical spirit or vital force which presided over and governed the various processes of the body. Each bodily function was supposed to have its own special b.; b. appears to be the counterpart of the archaeus of Paracelsus. [a Middle E. variant of blast]

Alfred, Austrian dermatologist, 1858–1922. See lines of B., under line.

Gerhard (Blaes), Dutch anatomist, 1626(?)–1692. See B. duct.

blast (blast)
General term for immature or precursor cell. [G. blastos, germ]

An immature precursor cell of the type indicated by the preceding word. [G. blastos, germ]

blastema (blas-te′ma)
1. The primordial cellular mass (precursor) from which an organ or part is formed. 2. A cluster of cells competent to initiate the regeneration of a damaged or ablated structure. [G. a sprout] metanephric b. SYN: metanephric cap. nephric b. the extension of nephrogenic cord tissue, caudal to the mesonephros, into which the ureteric buds grow to initiate development of the definitive mammalian kidney. SYN: nephroblastema.

blastemic (blas-tem′ik)
Relating to the blastema.

blastic (blas′tik)
1. Describing the formation of a conidium by the blowing out process of a fertile hypha before being limited by a septum. 2. Colloquial term for osteoblastic. [G. blastos, germ + -ic]

Pertaining to the process of budding (and the formation of buds) by cells or tissue. [G. blastos, germ]

blastocele (blas′to-sel)
The cavity in the blastula of a developing embryo. SYN: blastocoele, cleavage cavity, segmentation cavity. [blasto- + G. koilos, hollow]

blastocelic (blas-to-se′lik)
Relating to the blastocele. SYN: blastocoelic.

blastocoele (blas′to-sel)
SYN: blastocele.

blastocoelic (blas′to-se′lik)
SYN: blastocelic.

Blastoconidium (blas′to-co-nid′e-um)
A holoblastic conidium that is produced singly or in chains, and detached at maturity leaving a bud scar, as in the budding of a yeast cell. SYN: blastospore. [blasto- + conidium]

blastocyst (blas′to-sist)
The modified blastula stage of mammalian embryos, consisting of the inner cell mass and a thin trophoblast layer enclosing the blastocele. SYN: blastodermic vesicle. [blasto- + G. kystis, bladder]

Blastocystis (blas′to-sis′tis)
A genus of yeastlike parasites in the digestive tract of mammals; generally considered nonpathogenic. Its relationship to fungi is now being questioned owing to protozoan characteristics, such as lack of cell walls, a membrane-bound central body, pseudopod activity, protozoan type of Golgi apparatus and mitochondria, and reproduction by sporulation or binary fission rather than by budding. B. hominis a species of B. widespread among humans, formerly considered harmless, now recognized as a cause of diarrhea and other intestinal symptoms and eosinophilia when found in heavy infections.

blastocyte (blas′to-sit)
An undifferentiated blastomere of the morula or blastula stage of an embryo. [blasto- + G. kytos, cell]

blastoderm, blastoderma (blas′to-derm, -to-der′ma)
The thin, disk-shaped cell mass of a young embryo and its extraembryonic extensions over the surface of the yolk; when fully formed, all three primary germ layers (ectoderm, endoderm, and mesoderm) are present. SYN: germ membrane, germinal membrane, membrana germinativa. [blasto- + G. derma, skin] bilaminar b. the b. of a young embryo when it consists of only two of the three primary germ layers it will ultimately have. embryonic b. that part of the b. that takes part in the formation of the embryonic body. extraembryonic b. that part of the b. which is not incorporated in the embryo but forms membranes concerned in its nourishment and protection. trilaminar b. the b. after all three of the primary germ layers have been established.

blastodermal, blastodermic (blas-to-der′mal, -der′mik)
Relating to the blastoderm.

blastodisk (blas′to-disk)
1. The disk of active cytoplasm at the animal pole of a telolecithal egg. 2. The blastoderm, especially in very young stages when its extent is small.

blastogenesis (blas-to-jen′e-sis)
1. Reproduction of unicellular organisms by budding. 2. Development of an embryo during cleavage and germ layer formation. 3. Transformation of small lymphocytes of human peripheral blood in tissue culture into large, morphologically primitive blastlike cells capable of undergoing mitosis; can be induced by a variety of agents including phytohemagglutinin, concanavalin A, certain antigens to which the cell donor has been previously immunized, and leukocytes from an unrelated individual. [blasto- + G. genesis, origin]

blastogenetic, blastogenic (blas′to-je-net′ik, -to-jen′ik)
Relating to blastogenesis.

blastolysis (blas-tol′i-sis)
Dissolution or destruction of the blastocyst or blast cells and subsequent death. [blasto- + G. lysis, loosening]

blastolytic (blas-to-lit′ik)
Relating to blastolysis.

blastoma (blas-to′ma)
A neoplasm composed chiefly or entirely of immature undifferentiated cells resembling those that form the blastema or primordium of the organ in which the tumor arose. [blasto- + G. -oma, tumor]

blastomere (blas′to-mer)
One of the cells into which the egg divides after its fertilization. SYN: cleavage cell, embryonic cell. [blasto- + G. meros, part]

blastomerotomy (blas′to-mer-ot′o-me)
SYN: blastotomy. [blastomere + G. tome, incision]

blastomogenic (blas′to-mo-jen′ik)
Causing or producing a blastoma.

Blastomyces dermatitidis (blas-to-mi′sez der-ma-tit′i-dis)
A dimorphic soil fungus that causes blastomycosis. It grows in mammalian tissues as budding cells and in culture as a white to buff-colored filamentous fungus bearing spherical or ovoid conidia on terminal or lateral short, slender conidiophores. In its perfect (teleomorph) state it is known as Ajellomyces dermatitidis. [blasto- + G. mykes, fungus]

blastomycin (blas-to-mi′sin)
An antigen for intradermal testing prepared from sterile filtrates of cultures of the filamentous form of Blastomyces dermatitidis.

blastomycosis (blas′to-mi-ko′sis)
A chronic granulomatous and suppurative disease caused by Blastomyces dermatitidis; originates as a respiratory infection and disseminates, usually with pulmonary, osseous, and/or cutaneous involvement predominating. Formerly called North American b., the disease now has been found in African states as well as in Canada and the U.S. SYN: Gilchrist disease. Brazilian b. obsolete term for paracoccidioidomycosis. cutaneous b. verrucous or ulcerative skin lesions seen with infection with Blastomyces dermatitidis. North American b. b.. South American b. SYN: paracoccidioidomycosis. systemic b. infection with Blastomyces dermatitidis extending beyond the skin or the lung, the usual portals of entry; involvement of bone and genitourinary tract (esp. prostate and epididymis) are most frequent.

blastoneuropore (blas′to-noo′ro-por)
A temporary opening formed in some embryos by the union of the blastopore and neuropore. [blasto- + neuropore]

blastophore (blas′to-for)
An early stage of division of a coccidial schizont in which spheroid or ellipsoid structures are formed with a single peripheral layer of nuclei; merozoites form at the surface of the b. over each nucleus, grow out radially, and separate from the residual body (remnant of the b.); in a first-generation schizont such as Eimeria bovis, about 120,000 merozoites are produced. [blasto- + G. phoros, bearing]

blastopore (blas′to-por)
The opening into the archenteron formed by invagination of the blastula to form a gastrula. SYN: protostoma, protostome. [blasto- + G. poros, opening]

Blastoschizomyces (blas′to-skiz-o-mi′sez)
A genus of yeastlike fungi. B. capitatus fungal species that causes severe disseminated infection in immunosuppressed patients; formerly classified as a species of Geotrichum.

blastospore (blas′to-spor)
SYN: Blastoconidium. [blasto- + G. sporos, seed]

blastotomy (blas-tot′o-me)
Experimental destruction of one or more blastomeres. SYN: blastomerotomy. [blasto- + G. tome, incision]

blastula (blas′tu-la)
An early stage of an embryo formed by the rearrangement of the blastomeres of the morula to form a hollow sphere. [G. blastos, germ]

blastular (blas′tu-lar)
Pertaining to the blastula.

blastulation (blas-tu-la′shun)
Formation of the blastula or blastocyst from the morula.

Marc, French physician, *1878. See B. syndrome.

Blatta (blat′a)
A genus of insects (family Blattidae) that includes the abundant oriental cockroach, B. orientalis. The dried insect yields antihydropin, a diuretic principle. [L. cockroach]

Blattella (bla-tel′a)
A genus of cockroaches, (family Blattidae) that includes B. germanica, the German cockroach or croton bug, probably the most familiar and widespread of the cockroaches. [L. blatta, cockroach]

Blattidae (blat′i-de)
A family of insects (order Blattaria) consisting of over 4000 species of cockroaches, largely tropical but worldwide in distribution, including a number of abundant pests of households, kitchens, and institutions or facilities, wherever food is present; noxious wherever found, yet not positively incriminated in natural transmission of pathogenic organisms to man. Common household pests include the German cockroach, Blattella germanica, the American cockroach, Periplaneta americana, and the oriental cockroach, Blatta orientalis. [L. blatta, cockroach]

bleb (bleb)
1. A large flaccid vesicle. 2. An acquired lung cyst, usually less than 1 cm in diameter, similar to but smaller than a bulla, which is thought to be the most common cause of spontaneous pneumothorax. Blebs occur mainly in the apex of the lung. filtering b. a blister of conjunctiva resulting from glaucoma surgery by which a flap of sclera is created in the eye wall, allowing aqueous humor to percolate out of the eye and underneath the conjunctiva, thus lowering intraocular pressure. SYN: filtering cicatrix. pulmonary b. air-filled alveolar dilation less than 1 cm in diameter on the edge of the lung at the apex of upper lobe or superior segment of lower lobe; usually occurs in young people and can rupture, producing primary pneumothorax. Cf.:pulmonary bulla.

bleed (bled)
To lose blood as a result of rupture or severance of blood vessels.

bleeder (bled′er)
1. Colloquialism for a person suffering from hemophilia, Christmas disease, Osler disease, or other clotting disorder. 2. A blood vessel cut during a surgical procedure.

bleeding (bled′ing)
1. Losing blood as a result of the rupture or severance of blood vessels. 2. Phlebotomy; the letting of blood. dysfunctional uterine b. uterine b. due to a benign endocrine abnormality rather than to any organic disease. occult b. occult blood.

1. A small circumscribed alteration of the skin considered to be unesthetic but insignificant. 2. To alter the skin, rendering an unesthetic appearance.

blennadenitis (blen-ad-e-ni′tis)
Inflammation of the mucous glands. [G. blennos, mucus, + aden, gland, + -itis, inflammation]

blennemesis (blen-em′e-sis)
Rarely used term for vomiting of mucus. [G. blennos, mucus, + emesis, vomiting]

blenno-, blenn-
Mucus. [G. blenna, blennos]

blennogenic (blen-o-jen′ik)
SYN: muciparous. [blenno- + G. -gen, to produce]

blennogenous (ble-noj′e-nus)
SYN: muciparous.

blennoid (blen′oyd)
SYN: muciform. [blenno- + G. eidos, resemblance]

blennophthalmia (blen-of-thal′me-a)
1. SYN: conjunctivitis. 2. SYN: gonorrheal ophthalmia.

blennorrhagic (blen-o-raj′ik)
SYN: blennorrheal.

blennorrhea (blen-o-re′a)
1. Rarely used term for any mucous discharge, especially from the urethra or vagina. 2. In ophthalmic usage, was synonymous with conjunctivitis, but is now obsolete. [blenno- + G. rhoia, a flow] b. conjunctivalis SYN: gonorrheal ophthalmia. inclusion b. a neonatal conjunctivitis caused by Chlamydia trachomatis. b. neonatorum SYN: ophthalmia neonatorum.

blennorrheal (blen-o-re′al)
Rarely used term relating to blennorrhea. SYN: blennorrhagic.


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