PDF Lesson 2: Structure of the Mammalian Heart - Cary Academy

Name:_______________Date: _______________Binder #: ____________2.) Next, label Figure 1 (heart, rib cage, lungs, breast bone, pericardium, and spine) afterusing the Visible Human Viewer.Figure 1. Coronal section of a male near the heart created using the “Visible Human Viewer”-http://www.dhpc.adelaide.edu.au/projects/vishuman2/ . This figure is associated with the Vodcastcalled “Podcast/Vodcast 3.”Structure of the Human HeartThe heart is a hollow, muscular organ made of four chambers with multiple arteries (arteries arethe blood vessels that carry oxygenated blood) and veins (veins are the blood vessels that carryunoxygenated blood) connected to the heart. The top of the heart is called the base. Thepointed tip of the heart is called the apex. As seen in Figure 2, the right, top chamber of the heartis called the right atrium. The right, lower chamber is called the right ventricle. The left topchamber of the heart is called the left atrium, and the left bottom chamber is called the leftventricle. The two sides of the heart are separated by the thick walled septum. In between theright atrium and right ventricle is the tricuspid valve. Between the left atrium and the left ventricleis the bicuspid valve which is also called the mitral valve.Unoxygenated blood from the upper and lower body enters into the heart through the inferiorvena cava and the superior vena cava and enters into the right atrium. Once it enters into theright atrium it is pumped into the right ventricle and the tricuspid valve. Once the blood is in theright ventricle it is forcefully pumped out into the pulmonary artery through the pulmonary valve(not seen in Figure 2). The pulmonary valve prevents the blood from back flowing into the rightventricle. The blood moves through the pulmonary artery into the right and left lungs where it isoxygenated. The oxygenated blood returns to the heart through the right pulmonary veins andleft pulmonary veins. The blood enters into the left atrium and then is pumped into the leftventricle through the mitral valve (bicuspid valve). This valve prevents blood from back flowinginto the left atrium when the left ventricle contracts to push the blood through the aortic valve intothe aorta. Once blood is in the aorta it travels here to the rest of the body’s cells via arteries andeventually capillaries.joselyn_todd, All Right Reserved, © 2006 Page 2 10/22/2006