Each repetition of its back and forth motion is a little less vigorous than its previous repetition. If the head sways 3 cm to the right of its equilibrium position during the first repetition, it may only sway 2.5 cm to the right of its equilibrium position during the second repetition.
The majority of the heart is myocardium or cardiac muscle tissue. The endocardium is a thin layer of endothelium that lines the chambers of the heart and the valves. Pericardium. The pericardium (around the heart) is a triple-layered fluid-filled sac that surrounds the heart.
The endocardium is a thin layer of endothelium that lines the chambers of the heart and the valves. The pericardium (around the heart) is a triple-layered fluid-filled sac that surrounds the heart. The outer layer of this sac is the fibrous pericardium . It is a strong layer of dense connective tissue.