Circulation. Valves ensure blood does not flow back into the atria & ventricles : Right Atrium ...
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Transcript of Circulation. Valves ensure blood does not flow back into the atria & ventricles : Right Atrium ...
Cardiovascular SystemCirculation
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
PA
A
A
Revisit Systole & Diastole
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
Differences in VesselsArteries (“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
Differences in vessels, cont’dCapillaries:
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
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
Finalize the loopNow 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.
The Loop1. Right Atrium
(deoxygenated)2. Tricuspid Valve3. Right Ventricle4. Pulmonary Semilunar
Valve5. Pulmonary Artery6. Pulmonary Arterioles7. Pulmonary Capillaries
(CO2 dropped off O2 picked up)
8. Pulmonary Venules (oxygenated)
9. Pulmonary Veins>>>>
10. Left Atrium11. Bicuspid/Mitral Valve12. Left Ventricle13. Aortic Semilunar Valve14. Aorta15. Systemic Arteries16. Systemic Arterioles17. Systemic Capillaries (O2
dropped off, CO2 picked up)
18. Systemic Venules (deoxygenated)
19. Systemic Veins20. Superior/Inferior Vena
Cava
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.
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.
Blood return to the heart is affected byValvesA strongly beating heartAdequate arterial blood pressure“Milking action” of skeletal muscle
contractionChanging pressures in the chest cavity
caused by breathing
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?