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? Ans: The innermost layer of the heart wall is called the endocardium. 4. Name the depression between the two ventricles seen on the anterior surface of the heart. Ans: The depression between the two ventricles is the interventricular groove or interventricular sulcus.