Three major areas of study within ethics recognised today are: 1  Meta-ethics, concerning the theoretical meaning and reference of moral propositions, and how their truth values (if any) can be determined. 2  Normative ethics, concerning the practical means of determining a moral course of action.
In a healthy heart blood flows one way through the heart due to heart valves, which prevent backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a small amount of fluid. The wall of the heart is made up of three layers: epicardium, myocardium, and endocardium.he heart is a muscular organ in humans and other animals, which pumps blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients, and also assists in the removal of metabolic wastes.
The heart is made of a special kind of muscle called myocardium, and is enclosed in a double-layered, membranous sac called a pericardium. The heart lies in the chest cavity between the lungs. It is composed of four chambers, many large arteries and many veins. The four chambers are called atrium and ventricles. A wall of muscle divides the heart into two cavities: the left cavity pumps blood throughout the body, while the right cavity pumps blood only through the lungs. Two chambers of the heart lie in the left cavity and two chambers lie in the right cavity.