NEETZoologyExcretory Products and their Elimination
A patient experiences a significant drop in glomerular blood pressure. This change is detected by a special sensitive region in the nephron, which responds by releasing a specific chemical into the blood. Identify the anatomical structures that form this contact region and the chemical it releases.
Options
- ADistal convoluted tubule and afferent arteriole release rennin
- BDistal convoluted tubule and afferent arteriole release renin
- CProximal convoluted tubule and efferent arteriole release renin
- DDistal convoluted tubule and efferent arteriole release renin
Correct answer
B. Distal convoluted tubule and afferent arteriole release renin
Step-by-step solution
A drop in glomerular blood pressure or Glomerular Filtration Rate (GFR) activates the Juxtaglomerular Apparatus (JGA). The JGA is a special sensitive region formed by cellular modifications in the distal convoluted tubule (DCT) and the afferent arteriole at the location of their contact. Upon activation, the JG cells of this apparatus release the enzyme renin (spelled with a single 'n') into the blood. Renin converts angiotensinogen in blood to angiotensin I, initiating the RAAS pathway to increase blood pressure.