The CCIM Institute, headquartered in Chicago and an affiliate of the National Association of REALTORSÂ®, awards the CCIM designation to individuals who complete a process based both on commercial and investment real estate theory and practice. Weâll review this process in a moment.
Lesson Summary. The heart wall is composed of three main layers: the epicardium, myocardium, and endocardium. The pericardium (which is formed by the fibrous pericardium, the parietal pericardium and the epicardium) forms the outermost protective layer.
The Heart. Structure. The heart is divided into four chambers: the right atrium and right ventricle, and the left atrium and left ventricle. The walls of the chambers are made of a special muscle, the myocardium, which contracts rhythmically under the stimulation of electrical currents.