Transcript Document
Set Cornell Notes on pg. 29.4upCentral and Peripheral Nervous Systems 61 30.3 The Heart and Circulation 2.1 Atoms, Ions, •Topic: 30.3 The Heart and and Molecules Circulation •Essential Question(s): 1. On the top of pg. 60 please create a doublebubble map comparing and contrasting pulmonary and systemic circulation. Add a picture to each. KEY CONCEPT The heart is a muscular pump that moves the blood through two pathways. 30.1 Respiratory and Circulatory Functions Sponge • Think about the muscles in your body: – Do they get tired? – Hurt? – Sore? – Torn? • Now think about your heart. Does it do these things? 30.3 The Heart and Circulation KEY CONCEPT The heart is a muscular pump that moves the blood through two pathways. 30.3 The Heart and Circulation The tissues and structures of the heart make it an efficient pump. • Cardiac muscle tissue works continuously without tiring. NORMAL HUMAN HEART 30.3 The Heart and Circulation Regular heart vs. Enlarged Heart 30.3 The Heart and Circulation • The heart has four chambers: two atria, two ventricles. • Valves in each chamber prevent backflow of blood. • Muscles squeeze the chambers in a powerful pumping action. pulmonary valve aortic valve left atrium right atrium mitral valve left ventricle tricuspid right ventricle septum 30.3 The Heart and Circulation • The heartbeat consists of two contractions. 1) Sinoatrial (SA) node, or pacemaker, stimulates atria to contract LUB 2) Atrioventricular (AV) node stimulates ventricles to contract DUB Lub-dub SA node VA node Lub-dub Lub-dub 30.3 The Heart and Circulation • Blood flows through the heart in a specific pathway. 1. oxygen-poor blood enters right atrium 2. It pumps into the right ventricle, which pumps blood to lungs 3. oxygen-rich blood from lungs enters left atrium 4. It pumps into the left ventricle, which pumps blood to body 3 1 4 2 30.3 The Heart and Circulation Aorta Right Atrium Oxygen-poor blood Oxygen-rich blood Left Atrium Left Ventricle Right Ventricle 30.3 The Heart and Circulation 30.3 The Heart and Circulation The heart pumps blood through two main pathways. • Pulmonary circulation occurs between the heart and the lungs. – oxygen-poor blood enters lungs – excess carbon dioxide and water expelled (exhale) – blood picks up oxygen (inhale) – oxygen-rich blood returns to heart 30.3 The Heart and Circulation • Systemic circulation occurs between the heart and the rest of the body. – oxygen-rich blood goes to organs, extremities (arms/legs) – oxygen-poor blood returns to heart 30.3 The Heart and Circulation • The two pathways help maintain a stable body temperature.