Question: 179. Choose the correct statement given below regarding juxta medullary nephron.
(1) Juxta medullary nephrons are located in the coloumns of Bertini.
(2) Renal corpuscle of juxta medullary nephron lies in the outer portion of the renal medulla.
(3) Loop of Henle of juxta medullary nephron runs deep into medulla.
(4) Juxta medullary nephrons outnumber the cortical nephrons.
Answer: Option (3)
Explanation:
Juxtamedullary nephrons are nephrons whose renal corpuscles are located near the corticomedullary junction of the kidney.
The characteristic feature of juxtamedullary nephrons is that their Loop of Henle is very long
and extends deep into the renal medulla.
This long Loop of Henle plays a crucial role in the concentration of urine by maintaining a high osmotic gradient in the medulla.
Statement (1) is incorrect because nephrons are not located in the columns of Bertini.
Statement (2) is incorrect because the renal corpuscle lies in the cortex near the medulla,
not in the medulla.
Statement (4) is incorrect because cortical nephrons are more numerous,
forming about 85\% of total nephrons,
while juxtamedullary nephrons form about 15\%.
Therefore, the correct statement is that the Loop of Henle of juxtamedullary nephron runs deep into the medulla.