Question

Juxtaglomerular apparatus is made of
a. Juxtaglomerular cell. macula densa and lacis cell
b. Juxtaglomerular cell, lacis cell, and myoepithelial cell
c. Juxtaglomerular cell, lacis cell, and Purkinje cell
d. Juxtaglomerular cell. macula densa and argentaffin cell

Answer 1

Hint: Juxtaglomerular apparatus is also called as juxtaglomerular complex, and it got this name because it presents next to the glomerulus, and it is one of the structures in each kidney, that regulates the nephron, which is the functional unit of the kidney.

Complete answer:
Structure: Juxtaglomerular apparatus is a part of the nephron, next to the glomerulus and it is present between the afferent arteriole of the nephron and distal convoluted tubule of the same nephron, this juxtaglomerular apparatus is very critical in regulating the renal blood flow and the glomerular filtration rate.

This juxtaglomerular apparatus mainly consists of three types of cells by a name they are given below:
> Macula Densa - This is present in the distal convoluted tubule, these cells increase the glomerular filtration rate by the concept of purinergic signaling.

> Juxtaglomerular cells - These are also called granular cells and these cells secrete renin. These cells are present in the tunica media of the afferent arterioles, this cell stimulates beta-adrenergic receptors, they decrease the renal perfusion pressure, which decreases the NaCl concentration and this all finally decreases glomerular filtration rate.

Other types of cells are Extra glomerular mesangial cells, this is also called Lacis cells, which are present between the afferent and efferent arterioles, they are contractile in nature similar to smooth muscles and they regulate the glomerular filtration rate, by altering the vessel size.

Hence, the correct answer is option (A).

Note: Sometimes there is excessive secretion of renin, which activates the renin-angiotensin system, this results in the increase of more blood volume and causes hypertension, but this hypertension in not effective for normal medications used for hypertension, there should be a change or modification in the lifestyle.