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: Pathology
[{'content': 'Neointimal hyperplasia causes vascular graft failure as a result of hyperophy of - \nSelect and explain. \nA. Endothelial cells, B. Collagen fibers, C. Smooth muscle cells, D. Elastic fibers', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. is \'c\' i.e., Smooth Muscle Cells o After the placement of vascular grafts the primary change seen is intimal hyperplasia. o This hyperplastic change is usually confined to the graft intima and is commonly referred to as the "neo-intima", it consists predominantly of smooth muscle cells which develop directly under the graft endothelium. Why is it called neo-intima ? o Normally smooth muscles are present in the media. o In Neointima, the smooth muscle cells (usually reside in media) proliferate and migrate into the intima, so that this layer is histological similar to the combined intima and media of normal aery --> Hence the term neointima.', 'role': 'assistant'}]