Question

Mention the location and function of the juxtaglomerular apparatus.

Answer 1

Hint:Juxtaglomerular apparatus is an apparatus that is said to be associated with the kidneys and controls the release of hormone renin which carries out the conversion of angiotensinogen into angiotensin I and angiotensin II. It is composed of juxtaglomerular cells, mesangial cells, and the macula densa.

Complete answer: Juxtaglomerular apparatus as the name suggests is located in the juxta or the glomerular region of the kidney.
It has 3 types of cells -
1. Granular cells or Juxta cells
2. Mesangial cells
3. Macula densa
It controls the function of every single unit of the Kidney that is known as a nephron. Its main function is the regulation of blood pressure inside the human body. The juxta cells contain the hormone renin which is released when the blood pressure in the body drops, it is said to increase the blood pressure. Renin works on angiotensinogen and converts it into angiotensin1 and angiotensin2 which in turn increases the blood pressure. The role of macula densa is the regulation of the osmolarity, when the levels of osmolarity fall, it carries out the contraction of the afferent arteriole, which increases the pressure and hence the glomerular filtration rate.

Note: It should be noted that the juxtaglomerular apparatus indirectly controls the blood pressure by acting on the afferent arteriole and thereby causing its contracting which increases the blood pressure and ultimately leading to an increase in the Glomerular filtration rate.