1. CIRCULATORY SYSTEM
FUNCTION OF THE HEART

2. Four Main Functions of the Circulatory System
Pump
___________ is the pump that circulates blood to all parts of the body
Blood transport system around body
Arteries, veins, and capillaries are the structures that take blood from the heart
Carries oxygen and nutrients to cells, carries away waste products
Lymph system
Returns excess tissue fluid to general circulation

3. Heart (see figure 13-2 pg. 262) Avg. 72 bpm, 100,000 beats per day
Superior and inferior vena cava bring deoxygenated blood to the ________ atrium
Cardiopulmonary circulation
Circulation form the heart to the ________.
Pulmonary artery
Takes blood from the right ________ to the lungs
Pulmonary veins
Bring _______ blood from the lungs to the left atrium
Aorta
Takes blood from the left ventricle to the rest of the body
Four heart valves which are:

4. Pump Heart is a double pump
Which means what?
Now look at the board for the order circulation
Also see figure 13-5 pg. 266

5. Heart Sounds “Lubb dupp” sound Comes from the valves closing
Lubb sound is heard 1st and made by tricuspid and bicuspid closing (S1 sound)
Loudest at the apex
Dupp sound is heard 2nd and is shorter and higher pitched (S2 sound)
Caused by the semilunar and pulmonary valves closing

6. Electrical Activity SA (sinoatrial) node Pacemaker
Sends out electrical impulses, spreads impulse over the atria and makes them contract
AV (atrioventricular) node
Carries impulse to Bundle of His
Located b/t the atria and ventricle
Bundle of His
Conducting fivers in septum
Divides into left and right branches in ventricles to Purkunje fibers
Purkunje fibers
Cause ventricles to contract

7. Cardiac Cycle 1 (see figure 13-6 pg. 268)
SA node>stimulates both artia>blood flows from atria to ventricles via tricuspid and bicuspid valves
At same time ventricles are relaxed allowing them to fill with blood = seminular valves closed so blood cannot enter pulmonary artery or aorta

8. Cardiac Cycle 2
AV node>stimulates contraction of both ventricles>blood pumped into the pulmonary artery and aorta
Atria are relaxed and tricuspid and bicuspid valves close

9. Cardiac Cycle 3
Ventricles relax>semilunar valves close>heart rests briefly (repolarization)
Cycle then begins again with the signal from the SA node
Each cardiac cycle takes 0.8 seconds and represents one heart beat