1. Cardiovascular System
Circulation

2. Valves ensure blood does not flow back into the atria & ventricles :
Right Atrium  Tricuspid Valve  Right Ventricle  Pulmonary Semilunar Valve
 Pulmonary Artery/Arterioles  Lungs (Pulmonary Capillaries)  Pulmonary Venules /Veins 
Left Atrium  Bicuspid/Mitral Valve Left Ventricle  Aortic Semilunar Valve
 Aorta  Body

3. A PA A

4. Revisit Systole & Diastole

5. Once leaving the heart, the blood must make its way back:
Left Ventricle  Aortic Semilunar Valve 
Aorta 
Arteries 
Arterioles (O2) 
Systemic Capillaries 
(Gas Exchange: O2 /CO2)
Venules (DeO2) 
Veins 
Superior & Inferior Vena Cavae (Cava-s) 
Right Atrium

6. Differences in Vessels
Arteries (“A” for “away”)
ALWAYS carry blood AWAY from the heart
USUALLY carry oxygenated blood
Have thicker walls than veins
Veins
ALWAYS carry blood TO the heart
USUALLY carry deoxygenated blood
Have valves

7. Differences in vessels, cont’d
Capillaries:
Exchange O2 for CO2 at body cells and CO2 for O2 at the lungs
Are microscopic, walls only one cell thick--allowing for the above

8. Arteries usually carry oxygenated blood, veins usually carry deox - what’s the exception?
Heart  pulmonary artery(deO2)  pulmonary arterioles (deO2 )  capillaries of lungs, where blood becomes oxygenated
Capillaries of Lungs  pulmonary venules (O2)  pulmonary veins (O2)  heart

9. Finalize the loop
Now that you have been introduced to all components of the circulatory loop, put them all together to show exactly where blood travels.
Indicate whether the blood is oxygenated (O2) or deoxygenated (DeO2) and where gas exchange occurs.

10. The Loop Right Atrium (deoxygenated) Tricuspid Valve Right Ventricle
Pulmonary Semilunar Valve
Pulmonary Artery
Pulmonary Arterioles
Pulmonary Capillaries (CO2 dropped off O2 picked up)
Pulmonary Venules (oxygenated)
Pulmonary Veins>>>>
Left Atrium
Bicuspid/Mitral Valve
Left Ventricle
Aortic Semilunar Valve
Aorta
Systemic Arteries
Systemic Arterioles
Systemic Capillaries (O2 dropped off, CO2 picked up)
Systemic Venules (deoxygenated)
Systemic Veins
Superior/Inferior Vena Cava

13. Looking at this loop…
Why do you think that it is important that arteries have thicker walls than veins?
Arteries have thicker walls to withstand the high pressure of the blood coming from the heart -- caused by the heart’s contractions.

15. Looking at this loop…
Why do you think that it is important that veins have valves?
By the time blood reaches the veins, its velocity and pressure have decreased. Valves prevent the backflow of blood.

17. Blood return to the heart is affected by
Valves
A strongly beating heart
Adequate arterial blood pressure
“Milking action” of skeletal muscle contraction
Changing pressures in the chest cavity caused by breathing

18. The heart & blood vessels are important in supplying the cells of the body with O2. But…
What about the cardiac tissue itself? How does the heart get the O2 that it needs?