| juxtacortical osteogenic sarcoma | <tumour> A form of osteogenic sarcoma of relatively low malignancy, probably arising from the periosteum and initially involving cortical bone and adjacent connective tissue, which occurs in middle-aged as well as young adults and most commonly affects the lower part of the femoral shaft. Synonym: periosteal sarcoma. (05 Mar 2000) |
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| juxtacrine | A mode of hormone action that requires the cell producing the effector to be in direct contact with the cell containing the appropriate receptor. Origin: L. Juxta, close to, + G. Krino, to separate (05 Mar 2000) |
| juxtacrine activation | Activation of target cells by membrane anchored growth factors, also used for activation of leucocytes by PAF bound to endothelial cell surface. (18 Nov 1997) |
| juxtaepiphysial | Close to or adjoining an epiphysis. (05 Mar 2000) |
| juxtaglomerular | Close to or adjoining a renal glomerulus. (05 Mar 2000) |
| juxtaglomerular apparatus | A collective term for the juxtaglomerular cells in a nephron. These are specialised cells containing secretory granules, located in the tunica media of the afferent glomerular arterioles. They are receptors thought to stimulate secretion of the adrenal hormone aldosterone and to play a major role in renal autoregulation. (12 Dec 1998) |
| juxtaglomerular body | A collection of cells around the renal glomerular arterioles that contain cytoplasmic granules, probably composed of renin. Synonym: periarterial pad. (05 Mar 2000) |
| juxtaglomerular cells | Cell's, located at the vascular pole of the renal corpuscle that secrete renin and form a component of the juxtaglomerular complex; they are modified smooth muscle cell's primarily of the afferent arteriole of the renal glomerulus. Synonym: Goormaghtigh's cells. (05 Mar 2000) |
| juxtaglomerular complex | A complex consisting of the juxtaglomerular cells, which are modified smooth muscle cells in the wall of the afferent glomerular arteriole and sometimes also the efferent arteriole; extraglomerular mesangium lacis cells, which are located in the angle between the afferent and efferent glomerular arterioles; the macula densa of the distal convoluted tubule; and granular epithelial peripolar cells located at the angle of reflection of the parietal to the visceral capsule of the renal corpuscle; believed to provide some feedback control of extracellular fluid volume and glomerular filtration rate. Synonym: j-g complex, juxtaglomerular apparatus. (05 Mar 2000) |
| juxtaglomerular granules | Osmophilic secretory granule's present in the juxtaglomerular cells, thought to contain renin. (05 Mar 2000) |
| juxtallocortex | O. Vogt's collective term for several regions of the cerebral cortex which occupy an intermediate position between the isocortex and the allocortex. (05 Mar 2000) |
| juxtamedullary | Close to or adjoining the medullary border. (05 Mar 2000) |
| juxtamedullary glomerulus | A glomerulus close to the medullary border. (05 Mar 2000) |
| juxtaphrenic peak | On chest radiograph, a triangular density on top of the right diaphragmatic shadow, probably caused by tension of the phrenic nerve on the pleura over the diaphragm. (05 Mar 2000) |
| juxtaposition | A position side by side. See: apposition, contiguity. Origin: L. Juxta, near to, + positio, a placing, fr. Pono, pp. Positus, to place (05 Mar 2000) |