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 atria and the ventricles are separated by valves, which allow the blood to flow through the heart in one direction and prevent back flow of blood. The wall of the heart is made up of three layers. The outer layer is called the epicardium. The middle layer is the actual heart muscle and is called the myocardium. The inner layer of the heart is called the endocardium. The heart is contained within a sac called the pericardium. The sole purpose of the heart is to pump blood to and from the rest of the body.
What is the innermost layer of the heart wall called? The endocardium is the innermost layer of the heart wall. What is the innermost meningeal layer of the brain called? The pia mater is the delicate innermost layer of the meninges-the  membranes surrounding the brain and spinal cord. It is delicate and  vascular, and follows every contour oâ¦f the brain.