This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Excretory System (Kidney, Bladder) Acid-Base Balance, Subject name: Physiology
Juxtaglomerular apparatus lies in relation to; 
Select and explain. 
A. Proximal convoluted tubule, B. Ascending loop of Henle, C. Descending loop of Henle, D. Glomerulus
D: Glomerulus
Answer: D: Glomerulus 
Explanation: The proximal pa of the distal tubule comes in contact with the afferent aeriole. This complex of cells is called Juxtaglomerular apparatus. It lies in relation to glomerulus, and is made up of: Juxtaglomerular cells in afferent aeriole, Macula densa of the DCT, Agranular Polkissen or 'Lacis' cells situated in the angle created by the entrance and exit of afferent and efferent aerioles. Note: If the question asked is: "JG cells lie in close relation with....." and the options include ascending pa of DCT or descending pa of DCT, the answer would be ascending pa of DCT.