Distinguish between juxtaglomerular cells and macula densa.

Explanation

`star` The cells of the distal convoluted tubule are crowded in the region where distal convoluted tubule makes contact with affarent arteriole. These cells are known as Macula densa.
`star` Along side of macula densa, the wall of the affarent arteriole contains the modified smooth muscle fibers called juxtaglomerular cells.