This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology metabolism, Subject name: Physiology
Melatonin is secreted by- 
Select and explain. 
A. Hypothalamus, B. Adrenal cortex, C. Pineal gland, D. Melanocytes
C: Pineal gland
Answer: C: Pineal gland 
Explanation: Ans. is 'c? i.e.. Pineal gland o The pineal gland is a small cone shaped structure lies in the center of the brain behind the third ventricle. It consists of two types of cells : i) Pinealocytes, and ii) Neuroglial cell. Pinealocytes predominate and produce hormone melatonin (N-acetyl-5-methoxytry famine).