Question

Which of the following cells does not constitute the juxtaglomerular apparatus?

• A. Macula densa cells, which are present along the distal convoluted tubule.
• B. Juxtaglomerular cells, which are present in the wall of the afferent arteriole.
• C. Extraglomerularmesangial cells, which nestle in between the afferent and efferent arterioles.
• D. Podocytes, which are attached to the basement membrane

Answer 1

The correct option is D Podocytes, which are attached to the basement membrane

Podocytes are cells in the Bowman's capsule in the kidneys that wrap around capillaries of the glomerulus. The Bowman's capsule filters the blood, retaining large molecules such as proteins while smaller molecules such as water, salts, and sugars are filtered as the first step in the formation of urine.
The early distal convoluted tubule (first part) comes into close contact with the vascular portion of the renal corpuscle, specifically the afferent arteriole. There are three important types of cells here. The first type is the macula densa cell, which is present along the distal convoluted tubule. Next up are juxtaglomerular cells, which are present in the wall of the afferent arteriole. The third are the extraglomerular mesangial cells, which nestle in between the afferent and efferent arterioles. These three cells together constitute the juxtaglomerular apparatus