1. THE HEART LUNGS: Gas exchange

2. Structure of the Heart

3. the external surface of the heart is covered with blood vessels – the coronary arteries and veins
these provide food and oxygen for the muscle of the heart

5. there are 4 chambers inside the heart

6. there are 4 chambers inside the heart
2 atria (singular atrium)

7. RA LA
there are 4 chambers inside the heart
2 atria (singular atrium)

8. RA LA
there are 4 chambers inside the heart
2 atria (singular atrium)
2 ventricles

9. RA LA RV LV
there are 4 chambers inside the heart
2 atria (singular atrium)
2 ventricles

10. RA LA
valves RV LV
there are also valves that ensure the blood flows in the correct direction

11. RA LA RV LV
four blood vessels connect to the chambers of the heart

12. pulmonary vein RA LA RV LV
four blood vessels connect to the chambers of the heart
2 veins carrying blood to the heart

13. vena cava
pulmonary vein RA LA RV LV
four blood vessels connect to the chambers of the heart
2 veins carrying blood to the heart

14. vena cava
pulmonary vein RA LA RV LV
four blood vessels connect to the chambers of the heart
2 veins carrying blood to the heart
2 arteries carrying blood from the heart

15. vena cava
aorta
pulmonary vein RA LA RV LV
four blood vessels connect to the chambers of the heart
2 veins carrying blood to the heart
2 arteries carrying blood from the heart

16. vena cava
pulmonary artery
aorta
pulmonary vein RA LA RV LV
four blood vessels connect to the chambers of the heart
2 veins carrying blood to the heart
2 arteries carrying blood from the heart

17. RA LA RV LV
if we just look at the left side of the heart as it beats..

18. pulmonary vein RA LA RV LV

19. pulmonary vein RA LA
oxygenated blood from the lungs enters the left atrium via the pulmonary vein RV LV

20. pulmonary vein RA LA
oxygenated blood from the lungs enters the left atrium via the pulmonary vein RV LV

21. pulmonary vein RA LA
the left atrium contracts forcing blood through the valve into the left ventricle RV LV

22. pulmonary vein RA LA
the left atrium contracts forcing blood through the valve into the left ventricle RV LV

23. pulmonary vein RA LA
the left atrium contracts forcing blood through the valve into the left ventricle RV LV

24. pulmonary vein RA LA
the left atrium contracts forcing blood through the valve into the left ventricle RV LV

25. pulmonary vein RA LA
the left atrium contracts forcing blood through the valve into the left ventricle RV LV

26. aorta
pulmonary vein RA LA
the left ventricle contracts forcing blood out of the aorta to the body
the valve stops the blood flowing back into the left atrium RV LV

27. aorta
pulmonary vein RA LA
the left ventricle contracts forcing blood out of the aorta to the body
the valve stops the blood flowing back into the left atrium RV LV

28. aorta
pulmonary vein RA LA
the left ventricle contracts forcing blood out of the aorta to the body
the valve stops the blood flowing back into the left atrium RV LV

29. aorta
pulmonary vein RA LA
the left ventricle contracts forcing blood out of the aorta to the body
the valve stops the blood flowing back into the left atrium RV LV

30. aorta
pulmonary vein RA LA
the left ventricle contracts forcing blood out of the aorta to the body
the valve stops the blood flowing back into the left atrium RV LV

31. RA LA RV LV

32. RA LA
the left side of the heart receives oxygenated blood from the lungs and pumps it around the body RV LV

33. RA LA
the right side of the heart receives deoxygenated blood from the body and pumps it to the lungs to be oxygenated RV LV

34. The heart is divided into right and left sides
RIGHT SIDE
of heart
Receives
and pumps
DEOXYGENATED
BLOOD
LEFT SIDE
of heart
Receives
and pumps
OXYGENATED
BLOOD
4 chambers
ATRIA receive blood from VEINS
VENTRICLES pump blood away from heart in ARTERIES

35. Blood Vessels
The blood circulates around the body more than a thousand times a day
Arteries
Arterioles
Capillaries
Venules
Veins

37. Blood Vessels: Arteries
Carry blood Away from the heart
Carry oxygenated blood – except for the pulmonary artery which is going to the lungs to be re-oxygenated
Have thick, elastic walls to withstand high blood pressure
The blood moves in pulses due to the pumping action of the heart

39. Arterioles Smallest arteries Made mostly of smooth muscle
This means the diameter can vary, so blood can be diverted to where it is most needed.

40. Blood Vessels: Veins
Carry blood back to the heart – gravity means this is not an easy job!
Carry deoxygenated blood
Have thin walls because the blood travels at low pressure
Muscles around the veins contract to help move the blood back towards the heart
Veins have one-way valves to stop blood flowing backwards

41. Veins & Valves

42. Artery vs. Vein Structure
Thick muscular & elastic wall – gradually reduces the harsh surge of blood to a steadier flow
Larger Lumen (space in middle) – less resistance to blood flow

43. Blood Vessels: Capillaries
Join arteries to veins
Very tiny blood vessels that reach all the cells of the body – thin permeable walls
Capillaries provide cells with “food”, oxygen & water and remove wastes like carbon dioxide

44. Capillaries & transfer of materials