This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
The pacemaker of intestine is: 
Select and explain. 
A. Interstitial cells of cajal, B. Smooth muscle, C. Collagen fiber, D. All
A: Interstitial cells of cajal
Answer: A: Interstitial cells of cajal 
Explanation: The pacemaker of intestine is Interstitial cells of cajal. They in association with smooth muscle cells act as pacemakers Ref:Guyton and Hall textbook of medical physiology 12th edition,page number:395,396