The three mechanisms which regulate the heart are endocrine, cardiovascular and Sinoatrial nodes. The endocrine system consists of the glands and hormones of the human body. The cardiovascular system is the organ system which is responsible for the circulation of the blood around the body and the oxygenation of the body's tissues. The sinoatrial node (SA node) generates the electrical impulses and is considered the natural pacemaker of the heart.
The two sisters though identical have some differences while the former avoids fatty meals and cholesterol the latter enjoys fatty meals in contrast with the statement they both exercise daily which burns out the fat
