Editing Nephron (section)

=== Juxtaglomerular apparatus ===
{{main|Juxtaglomerular apparatus}}
The [[juxtaglomerular apparatus]] (JGA) is a specialized region associated with the nephron, but separate from it. It produces and secretes into the circulation the enzyme [[renin]] (angiotensinogenase), which cleaves [[angiotensinogen]] and results in the ten amino acid substance angiotensin-1 (A-1).  A-1 is then converted to angiotensin-2, a potent vasoconstrictor, by removing two amino acids: this is accomplished by angiotensin converting enzyme (ACE). This sequence of events is referred to as the [[renin–angiotensin system]] (RAS) or renin-angiotensin-aldosterone system (RAAS). The JGA is located between the thick ascending limb and the afferent arteriole. It contains three components: the [[macula densa]], [[juxtaglomerular cell]]s, and [[extraglomerular mesangial cell]]s.<ref name="junqueiras" />{{rp|404}}