Objectives 30.3 Identify the main structures of the heart Describe the functions of each of the main structures of the heart Trace the path of a RBC as it flows through the heart, starting from its entry into the right atrium. Distinguish between systemic and pulmonary circulation
Warm up: What structures carry blood to and from the heart?
KEY CONCEPT The heart is a muscular pump that moves the blood through two pathways.
The tissues and structures of the heart make it an efficient pump. Cardiac muscle tissue works continuously without tiring. NORMAL HUMAN HEART
The heart has four chambers: two atria, two ventricles. Valves in each chamber prevent backflow of blood. aortic valve left atrium mitral valve left ventricle septum pulmonary valve right atrium tricuspid right ventricle Muscles squeeze the chambers in a powerful pumping action.
The heartbeat consists of two contractions. SA node, or pacemaker, stimulates atria to contract AV node stimulates ventricles to contract SA node VA node
Blood flows through the heart in a specific pathway. 3 1 4 2
Blood flows through the heart in a specific pathway. 1) oxygen-poor blood enters right atrium, then right ventricle 2) right ventricle pumps blood to lungs 3) oxygen-rich blood from lungs enters left atrium, then left ventricle 4) left ventricle pumps blood to body
The heart pumps blood through two main pathways. Pulmonary circulation occurs between the heart and the lungs. 1) oxygen-poor blood enters lungs 2) excess carbon dioxide and water expelled 3) blood picks up oxygen 4) oxygen-rich blood returns to heart
Systemic circulation occurs between the heart and the rest of the body. 1) oxygen-rich blood goes to organs, extremities 2) oxygen-poor blood returns to heart The two pathways help maintain a stable body temperature.
You will be graded for neatness and accuracy. Next: You are going to create a poster showing both pulmonary and systemic circulation, as well as blood flow through the heart. Be thorough and include all colors, labels, and steps that we talked about today. You will be graded for neatness and accuracy. There is a picture on page 920 in your book for you to follow. Make sure to include the steps from your notes.