1. 29.4 Central and Peripheral Nervous Systems Set up Cornell Notes on pg. 61 Topic: 30.3 The Heart and Circulation Essential Question(s): 1.On the top of pg. 60 please create a double- bubble map comparing and contrasting pulmonary and systemic circulation. Add a picture to each. 2.1 Atoms, Ions, and Molecules 30.3 The Heart and Circulation KEY CONCEPT The heart is a muscular pump that moves the blood through two pathways.

2. 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?

3. 30.3 The Heart and Circulation KEY CONCEPT The heart is a muscular pump that moves the blood through two pathways.

4. 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

5. 30.3 The Heart and Circulation Regular heart vs. Enlarged Heart

6. 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. aortic valve left atrium mitral valve left ventricle septum pulmonary valve right atrium tricuspid right ventricle

7. 30.3 The Heart and Circulation 1) Sinoatrial (SA) node, or pacemaker, stimulates atria to contract LUB 2) Atrioventricular (AV) node stimulates ventricles to contract DUB SA node VA node The heartbeat consists of two contractions. Lub-dub

8. 30.3 The Heart and Circulation 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 Blood flows through the heart in a specific pathway. 1 2 3 4

9. 30.3 The Heart and Circulation Aorta Right Atrium Left Atrium Right Ventricle Left VentricleOxygen-poor blood Oxygen-rich blood

10. 30.3 The Heart and Circulation

11. 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

12. 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

13. 30.3 The Heart and Circulation The two pathways help maintain a stable body temperature.