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
The MOST abundant source of ghrelin is: 
Select and explain. 
A. Gastric fundus, B. Gastric body, C. Gastric pylorus, D. First pa of duodenum
A: Gastric fundus
Answer: A: Gastric fundus 
Explanation: Ghrelin is a 28 amino acid peptide mainly secreted from stomach and the most abundant source is gastric fundus. It also produced from intestine, pancreas, pituitary, kidney, placenta. ACTION: It increases growth hormone secretion It increases food intake It increases weight gain Ref: Sleisenger and Fordtran's, Edition-9, Page-8.