| posterior median fissure of the medulla oblongata | The longitudinal groove marking the posterior midline of the medulla oblongata; continuous below with the posterior median sulcus of the spinal cord. Synonym: sulcus medianus posterior medullae oblongatae, posterior median fissure of the medulla oblongata. (05 Mar 2000) |
|---|---|
| posterior median line | The line of intersection of the midsagittal plane with the posterior surface of the body. Synonym: linea mediana posterior. (05 Mar 2000) |
| posterior median sulcus of medulla oblongata | The longitudinal groove marking the posterior midline of the medulla oblongata; continuous below with the posterior median sulcus of the spinal cord. Synonym: sulcus medianus posterior medullae oblongatae, posterior median fissure of the medulla oblongata. (05 Mar 2000) |
| posterior median sulcus of spinal cord | A shallow furrow in the median line of the posterior surface of the spinal cord. Synonym: sulcus medianus posterior medullae spinalis, posterior median fissure of spinal cord. (05 Mar 2000) |
| lateral root of median nerve | <anatomy, nerve> The part of the median nerve arising from the lateral cord of the brachial plexus. Synonym: radix lateralis nervi mediani. (05 Mar 2000) |
| adrenal cyst | <radiology> Same characteristics as renal cysts, but less common, thick wall, septations, calcifications suggests pseudocyst (12 Dec 1998) |
| adventitious cyst | 1. An accumulation of fluid in a cystlike loculus, but without an epithelial or other membranous lining. Synonym: adventitious cyst, false cyst. 2. A cyst whose wall is formed by a host cell and not by a parasite. 3. A mass of 50 or more Toxoplasma bradyzoites, found within a host cell, frequently in the brain; formerly called a pseudocyst, but now considered a true cyst enclosed in its own membrane within the host cell that may rupture to release particles that form new cysts, and apparently is infective to another vertebrate host. See: bradyzoite. Origin: pseudo-+ G. Kystis, bladder (05 Mar 2000) |
| allantoic cyst | Cyst occurring in a persistent portion of the urachus, presenting as an extraperitoneal mass in the umbilical region. It is characterised by abdominal pain, and fever if infected. It may rupture, leading to peritonitis, or it may drain through the umbilicus. (12 Dec 1998) |
| alveolar hydatid cyst | A hydatid cyst of a multiloculate type, usually in the liver, caused by Echinococcus multilocularis, adults of which are in foxes; larvae (alveolar hydatid) are found chiefly in microtine rodents, but also among humans such as trappers and others handling pelts of infected foxes and other carnivores; growth is by exogenous budding and is not limited by an outer laminated membrane as in the hydatid cyst from E. Granulosus; necrosis, cavitation, contiguous spread, and death usually ensue. Synonym: multilocular hydatid cyst, multiloculate hydatid cyst. (05 Mar 2000) |
| aneurysmal bone cyst | <radiology> ABC, 10 - 30 yrs, 75% before skeletal maturity, sites: long bones; also, flat bones Findings: metaphyseal if unfused, metaepiphyseal after fusion, lytic, expansile, thin, continuous rim, thin internal bony strands (12 Dec 1998) |
| angioblastic cyst | Mesenchymal tissue capable of forming blood in the embryo. (05 Mar 2000) |
| apical periodontal cyst | An inflammatory odontogenic cyst derived histogenetically from Malassez' epithelial rests surrounding the root apex of a nonvital tooth. Synonym: periapical cyst, radicular cyst, root end cyst. (05 Mar 2000) |
| apoplectic cyst | A pseudocyst formed of extravasated blood as in a stroke. (05 Mar 2000) |
| arachnoid cyst | A fluid-filled cyst lined with arachnoid membrane, frequently situated near the lateral aspect of the fissure of Sylvius; usually congenital in origin. Synonym: leptomeningeal cyst. (05 Mar 2000) |
| baker cyst | <radiology> Bursal fluid collection between: medial head of gastrocnemius muscle and, semimembranosus tendon, associated with knee injury, may contain osteocartilaginous fragments (12 Dec 1998) |