Question

Juxtaglomerular apparatus is made up of

• A. juxtaglomerular cells, macula densa and lads cells
• B. juxtaglomerular cells, Purkinje cells and chief cells
• C. juxtaglomerular cells, lads cells and myoepithelial cells
• D. juxtaglomerular cells, macula densa and argentaffin cells.

Hint:

The juxtaglomerular apparatus is a specialized structure found in the kidneys, primarily in the renal cortex. 

Answer 1

The Correct Option is A

Juxtaglomerular cells are the smooth muscle cells of both the afferent and efferent arterioles that are swollen and contain dark granules. These cells secrete renin. In these specialized cells, the afferent arteriole comes in contact with the distal convoluted tubule. 

• Macula densa are the epithelial cells of the distal convoluted tubule that come in contact with the afferent and efferent arterioles.
• These cells are more dense than the other tubular cells. They act as chemoreceptors.
• Lads cells are located between the macula densa and the afferent and efferent arterioles.
• The function of lacis cells is unknown.
• All these cells make up the juxtaglomerular apparatus.

Therefore, The Juxtaglomerular apparatus comprises the Juxtaglomerular cells, macula densa and lacis cells. So, the correct answer is Option A.

Read More From Chapter: Excretory Products and their Elimination

Answer 2

The Correct Answer is (A)

Real Life Applications

• Juxtaglomerular apparatus (JGA) can be used to maintain high blood pressure. The medicine will inhibit the production of renin.
• It can also be used to diagnose the diseases of the kidney as the proper functioning of JGA is needed for the kidney to function properly.

Question can also be asked as

• What are the components of the juxtaglomerular apparatus? What is juxtaglomerular apparatus?
• What is the function of the juxtaglomerular apparatus?

Answer 3

The Correct Answer is (A)

The juxtaglomerular apparatus is a specialized structure found in the kidneys, primarily in the renal cortex. 

• It plays a crucial role in regulating renal blood flow, blood pressure, and sodium balance.
• Comprising three main components - juxtaglomerular cells, macula densa, and lacis cells - the juxtaglomerular apparatus has an intricate feedback mechanism to maintain homeostasis.

Juxtaglomerular Cells

• Juxtaglomerular cells are specialized smooth muscle cells found in the walls of the afferent arterioles.
• They are capable of sensing changes in blood pressure and secreting the enzyme renin in response to low blood pressure.

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Macula Densa

• The macula densa is a group of specialized epithelial cells located in the distal convoluted tubule.
• These cells monitor the sodium chloride concentration in the tubular fluid to provide feedback to the juxtaglomerular cells.

Lacis Cells

• Lacis cells are found near the juxtaglomerular cells and macula densa.
• They provide structural support to the juxtaglomerular apparatus and help regulate the local blood flow within the glomerulus.

The juxtaglomerular apparatus, particularly the juxtaglomerular cells, plays a pivotal role in the activation of the renin-angiotensin-aldosterone system. Renin initiates a cascade of events leading to the production of angiotensin II, a potent vasoconstrictor, and aldosterone secretion, promoting sodium reabsorption.