Juxtaglomerular apparatus: The prefix "juxta-" comes from the Latin preposition meaning near, nearby, close.
The juxtaglomerular apparatus is a collective term referring to the cells near a structure called the glomerulus in the kidney. The juxtaglomerular cells are specialized cells that stimulate the secretion of the adrenal hormone aldosterone and play a major role in renal autoregulation, the kidney's self-governance.
The JGA is also important in the regulation of salt excretion.