This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Male Genital System, Subject name: Anatomy
Blood-testis barrier is formed by - 
Select and explain. 
A. Sertoli cells, B. Leydig cells, C. Epididymis, D. Vas deferens
A: Sertoli cells
Answer: A: Sertoli cells 
Explanation: Ans. is 'a' i.e., Sertoli cells o Blood brain barrier - Tight junction between endothelial cells and some reinforcement by foot process of astrocytes.o Blood CSF barrier -Tight juction between endothelial cells plus tight junction between choroidal epithelial cells.o Blood testis barrier - Tight junction betw-een endothelial cells plus sertoli cells.