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 pericardium is a double-walled sac that contains the heart and the roots of the great vessels. The outer wall of the pericardium is composed of dense connective tissue. The portion of the inner wall of the pericardium that is in contact with the heart (but not in contact with the great vessels) is the epicardium. The epicardium contains the blood vessels supplying blood to heart muscle (the coronary arteries) as well as nerve fibers.