| visceral larva migrans | A disease, chiefly of children, caused by ingestion of infective ova of Toxocara canis, less commonly by other ascarid nematodes not adapted to humans, whose larvae hatch in the intestine, penetrate the gut wall, and wander in the viscera (chiefly the liver) for periods of up to 18 or 24 months; may be asymptomatic or may be marked by hepatomegaly (with granulomatous lesions caused by encapsulated larvae in the enlarged liver), pulmonary infiltration, fever, cough, hyperglobulinaemia, and sustained high eosinophilia. (05 Mar 2000) |
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| visceral leishmaniasis | A chronic disease, occurring in India, Assam, China, the area formerly known as the Mediterranean littoral areas, the Middle East, India, Pakistan, China, South and Central America, Asia, Africa caused by Leishmania donovani and transmitted by the bite of an appropriate species of sandfly of the genus Phlebotomus or Lutzomyia; the organisms grow and multiply in macrophages, eventually causing them to burst and liberate amastigote parasites which then invade other macrophages; proliferation of macrophages in the bone marrow causes crowding out of erythroid and myeloid elements, resulting in leukopenia, and anaemia, splenomegaly, and hepatomegaly which are characteristic, along with enlargement of lymph nodes; fever, fatigue, malaise, and secondary infections also occur; different strains of leishmaniasis donovani occur; leishmaniasis infantum in Eurasia, leishmaniasis chagasi in Latin America. Synonym: Assam fever, black sickness, Burdwan fever, cachectic fever, Dumdum fever, kala azar, tropical splenomegaly. (05 Mar 2000) |
| visceral lymph nodes | The lymph nodes draining the viscera of the abdomen or of the pelvis. Synonym: nodi viscerales, visceral nodes. (05 Mar 2000) |
| visceral lymphomatosis | See: avian lymphomatosis. (05 Mar 2000) |
| visceral mesoderm | The splanchnic mesoderm or the branchial mesoderm. (05 Mar 2000) |
| visceral motor neuron | See: motor neuron. (05 Mar 2000) |
| visceral muscle | <anatomy, pathology, physiology> Muscle tissue in vertebrates made up from long tapering cells that may be anything from 20-500m long. Smooth muscle is generally involuntary and differs from striated muscle in the much higher actin/myosin ratio, the absence of conspicuous sarcomeres and the ability to contract to a much smaller fraction of its resting length. Smooth muscle cells are found particularly in blood vessel walls, surrounding the intestine (particularly the gizzard in birds) and in the uterus. The contractile system and its control resemble those of motile tissue cells (e.g. Fibroblasts, leucocytes) and antibodies against smooth muscle myosin will cross react with myosin from tissue cells, whereas antibodies against skeletal muscle myosin will not. See: dense bodies. (18 Nov 1997) |
| visceral nerve | <anatomy, nerve> A term describing nerves conveying autonomic (general visceral efferent) fibres. (05 Mar 2000) |
| visceral nervous system | <anatomy> Neurons that are not under conscious control, comprising two antagonistic components, the sympathetic and parasympathetic nervous systems. The autonomic nervous system regulates key functions including the activity of the cardiac (heart) muscle, smooth muscles (e.g., of the gut), and glands. The autonomic nervous system has two divisions: 1. The sympathetic nervous system that accelerates the heart rate, constricts blood vessels, and raises blood pressure. 2. The parasympathetic nervous system slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles. (03 Jul 1999) |
| visceral nodes | The lymph nodes draining the viscera of the abdomen or of the pelvis. Synonym: nodi viscerales, visceral nodes. (05 Mar 2000) |
| visceral pelvic fascia | Covers the pelvic organs and surrounds vessels and nerves in the subperitoneal space. Synonym: endopelvic fascia, fascia pelvis visceralis. (05 Mar 2000) |
| visceral pericardium | The layer of the pericardial sac on the epicardial surface of the heart. It is composed mainly of a single layer of mesothelium. (05 Mar 2000) |
| visceral peritoneum | The layer of peritoneum investing the abdominal organs. Synonym: peritoneum viscerale. (05 Mar 2000) |
| visceral plate | The inner of the two layers of the lateral mesoderm; the splanchnic mesoderm that becomes associated with the endoderm and together with it constitutes the splanchnopleure. (05 Mar 2000) |
| visceral pleura | The layer investing the lungs and dipping into the fissures between the several lobes. Synonym: pleura pulmonalis, pleura visceralis, pulmonary pleura. (05 Mar 2000) |