The document discusses the structure and function of the mammalian heart. It describes the major components of the heart including the atria, ventricles, tendinous cords, and valves. It explains the cardiac cycle which involves the coordinated contraction and relaxation of the atria and ventricles. The cardiac cycle allows for the flow of blood through the heart in two main stages: atrial systole which fills the ventricles, and ventricular systole which pumps blood from the heart.

1. The mammalian heart
Chapter 1B

2. Learning objectives
Relate the structure and operation of the mammalian
heart, including the major blood vessels, to its function.
Know the cardiac cycle

3. The structure of the heart

5. Tendinous cords and valves

6. Foramen ovale

7. Heart sounds (lub-dub)
 Lub – closing of AV valves
 Dub – closing of SL valves

8. Cardiac cycle
 Contraction of cardiac muscle – systole
 Relaxation of cardiac muscle – diastole
 Main stages of cardiac cycle(takes nearly 0.8 seconds):
 1. Atrial systole
 2. Ventricular systole
 3. Diastole

9. Position of valves in cardiac cycle
AV valves SL valves
Atrial systole Open Closed
Ventricular systole Closed Open
Diastole Open Closed