This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Which are all the factors determining the GFR? 
Select and explain. 
A. Afferent aeriolar resistance, B. Efferent aeriolar resistance, C. Aerial pressure, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Ans. D. All of the aboveDeterminants of GFR:Increase glomerular capillary hydrostatic pressure increases GFR. Glomerular hydrostatic pressure is determined by the following variables : i) Aerial pressure, ii)Afferent aeriolar resistance; iii) Efferent aeriolar resistance.Contraction of mesangial cells (therefore decrease in GFR) is produced by : - Endothelin, angiotensin II, vasopressin, norepinephrine, PAF, PDGF, thromboxane A2,PGF2, Leukotrienes C4 & D4, Histamine.