This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: BIO 188 November 18, 2009 BIO 188 November 18, 2009 1. Today: 1. start with p. 5 from Mon notes (finish dual circuits) 2. minimal heart anatomy in lecture 1. you need to know whats in notes so we can talk 3. cardiac cycle 1. pressure and valves 4. how does a heart beat? 1. role of pacemaker cells Since 3-chambered hearts can segregate pulmonary and systemic circulations pretty well, why natural selection for 4-chambered hearts? Hypotheses? 2. Complete separation of pulmonary and systemic circuits 1. doesnt seem to be 1 advantage 3. With 3-chambered heart, systemic and pulmonary circuits have same blood systemic and pulmonary circuits have same blood pressure pressure 1. seen in crocodiles, birds, mammals Oxygenated blood in systemic arteries is bright red. What color is deoxygenated blood in systemic veins? How is direction of blood flow through the heart controlled? 4. Mechanical valves . Prevent baclflow 1. similar on L and R sides 2. atrioventricular (AV) valves: between atrium and ventricle 3. aortic and pulmonary valves: where are they?...... 5. Opening and closing of valves is passive ! 1. due to differences in blood pressure (P) across valve Cardiac Cycle keeps going and going and going Cardiac Cycle keeps going and going and going What is the cardiac cycle? What is the cardiac cycle? 6. Two phases: 1. Systole Systole : ventricles ventricles contract and eject blood contract and eject blood 2....
View Full Document
- Spring '08