what are the walls of the heart composed of
Heart In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria; and lower left and right ventricles.[4][5] Commonly the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart.[6] Fish, in contrast, have two chambers, an atrium and a ventricle, while reptiles have three chambers.[5] In a healthy heart blood flows one way through the heart due to heart valves, which prevent backflow.[3] 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.[7]
Rate equation k is the first order rate constant, which has units of 1/s or sâˆ’1.
Thalamus It is a midline symmetrical structure of two halves, within the vertebrate brain, situated between the cerebral cortex and the midbrain.
United States House of Representatives The United States House of Representatives is the lower chamber of the United States Congress. The Senate is the upper chamber. Together they compose the legislature of the United States.