juxtaglomerular apparatus


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apparatus

 [ap″ah-rat´tus] (pl. appara´tus, apparatuses)
an arrangement of a number of parts acting together to perform a special function.
Golgi apparatus see golgi apparatus.
juxtaglomerular apparatus a collective term for the juxtaglomerular cells in a nephron.
lacrimal apparatus see lacrimal apparatus.
Wangensteen's apparatus a nasal suction apparatus connected with a duodenal tube for aspirating gas and fluid from stomach and intestine.

jux·ta·glo·mer·u·lar com·plex

a complex consisting of (a) the juxtaglomerular cells, which are modified smooth muscle cells in the wall of the afferent glomerular arteriole and sometimes also the efferent arteriole; (b) extraglomerular mesangium (lacis cells), which are located in the angle between the afferent and efferent glomerular arterioles; (c) the macula densa of the distal tubule; and (d) granular epithelial peripolar cells located at the angle of reflection of the parietal to the visceral capsule of the renal corpuscle; provides feedback control of extracellular fluid volume and glomerular filtration rate by activating the renin-angiotensin system.

juxtaglomerular apparatus

The juxtaglomerular cells of the afferent arteriole and the macula densa of the distal tubule. This structure initiates the renin-angiotensin mechanism to elevate blood pressure and increase sodium retention.