1. Comparative Vertebrate Physiology Cardiovascular systems in vertebrates

2. Fish Heart anatomy

3. Fish Blood flow pathway

4. Amphibians Heart anatomy (spiral fold) Blood pathway (Spiral valve)

5. Reptiles Heart anatomy Ventricle divided into 3 chambers

6. Reptiles Blood flow pathway (non-crocodiles) Advantage during diving

7. Reptiles Crocodiles Heart anatomy Foramen of Panizza

8. Reptiles Blood flow pathway Advantage during diving

9. Birds Heart anatomy Renal portal shunt

10. Mammals Heart anatomy 4 chambers AV valves tricuspid, bicuspid Semilunar valves aortic, pulmonary

11. Conduction pathway Myogenic pacemaker

12. Conduction pathway Excitation sequence

13. Heart rate fluctuations Sympathetic parasympathetic influence

14. Pacemaker potential

15. Cardiac action potentials Amplitude, configuration and duration of AP’s differ at different sites of the heart

16. Refractory period Prolonged

17. Refractory period Prolonged Ca ++ and K + permeability

18. Ectopic pacemaker Extra heartbeat followed by a pause

19. Electrocardiogram

20. Ectopic pacemaker Cause: AV node taking over role of damaged SA node

21. Ectopic pacemaker Cause: blockage of conductive pathway

22. Cardiac cycle Systole/diastole Mid-to-late diastole Atria and ventricles relaxed Ventricles fill 80% Aortic and pulmonary valves closed SA node discharge 20% filling of ventricles EDV

23. Cardiac cycle Ventricular systole QRS complex First heart sound Isometric pressure build up Opening of aortic and pulmonary valves ESV Aortic pressure rises then falls Atrial pressure rises

24. Cardiac cycle Early diastole T wave 2nd. Heart sound (closure of aortic and pulmonary valves, dicrotic notch) AV valves open Atria fill with blood

25. Heart sounds Lub Caused by closure of AV valves Onset of systole Dub Caused by closure of aortic and pulmonary valves Onset of diastole