This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Embryology and abdominal wall layer, Subject name: Anatomy
Kupffer cells present in the adult liver are derived from 
Select and explain. 
A. Mesoderm, B. Endoderm, C. Ectoderm, D. Neuroectoderm
A: Mesoderm
Answer: A: Mesoderm 
Explanation: Kupffer cells are actually macrophages and are derived from mesoderm. Hepatocytes and the epithelial lining of the intrahepatic biliary tree are derived from endoderm diveiculum of forgut.