Answer:
Heart is made of strong cardiac muscle with the closed fist of a man. It position is behind the sternum in between the lungs,nearly2/3rd of the part falling on the left hand side and remaining 1/3rd to the right side of the sternum .It weight nearly 450 grams in grown up males but weight less(about 300grams) in women The number of heart beats minute in an adult is about 72.