1. Features of a good transport system
A fluid to carry nutrients and gases
A pump to create pressure that will push fluid around the body
Exchange surfaces
Tubes or vessels – to carry fluid

2. Pulmonary cirulation – carries blood to the lungs to pick up oxygen
Single circulation
Double circulation:
Pulmonary cirulation – carries blood to the lungs to pick up oxygen
Systemic circulation – carries the oxygen and nutrients around the body to tissues.
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4. Advantages of a Double Circulation
Heart increases the pressure on blood after it has passed through the lungs so blood flows more quickly to the body tissues.
Systemic circulation can be at a higher pressure than the pulmonary circulation
Blood pressure in pulmonary system cannot be too high as it could damage lungs.

6. PULMONARY ARTERY
AORTA
PULMONARY VEIN
VENA CAVA
SEMI LUNAR
VALVE
LEFT ATRIUM
RIGHT ATRIUM
LEFT VENTRICLE
ATRIOVENTRICULAR
VALVES
RIGHT VENTRICLE

7. Valves in the heart prevent the backflow of blood

8. The internal structure of the heart
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9. Structure of the Heart

10. Why is a mammalian heart is divided into a right and left side?
Keeps oxygenated and deoxygenated blood separate
Allows as much oxygen as possible to be carried to the tissues
Allows different pressures to exist – left more pressure required to force blood to body
whereas right side requires less as forcing blood a shorter distance to lungs

11. Main adaptations of the heart
Composed of cardiac muscle
A specialised tissue that can contract automatically,
powerfully and without fatigue.
All cells in cardiac muscle are connected by specialised junctions called intercalated discs.
This allows the rapid spread of impulses through the muscle ensuring that all cells contract at the same time

12. Main adaptations of the heart
Thickness of the walls
The thickness of the walls in the different heart chambers reflects their function.
Atria: thin muscle as only pumps blood a short distance
Right Ventricle: thicker muscle than atria – forcing blood a further distance to lungs.
Left Ventricle: thickest walls – has to force blood all the way round body

13. Main adaptations of the heart
Valves
Ensure unidirectional flow through the heart and prevent backflow.
The AV valves
Location: between atria and ventricle
Function: to prevent blood flowing back into atria when ventricles contract
The Semilunar valves
Location: found at the openings of the aorta and pulmonary artery
Function: prevent backflow of blood into ventricles during diastole

14. Valve structures

15. The cardiac cycle © Pearson Education Ltd 2008
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16. Semi-lunar valves open
Atrial Systole
AV valves open
semi-lunar valves
closed
AV valves close
Filling of
ventricles
atrial systole
Ventricle
muscles contract
Pressure increases
Ventricular Systole
Ventricular Diastole
Semi-lunar valves
close
Ventricles relax
Semi-lunar valves open
Blood enters arteries
Pressure in the
ventricles falls
AV valves open

17. Action of the atrioventricular valves
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18. Describe the sequence of events involved in one heart beat
atrial systole / atria contract ;
blood passes into ventricles ;
atrioventricular / AV valves open ;
ventricular systole / ventricles contract ;
blood to, the arteries /Aorta and Pulmonary Artery;
via open, semilunar valves ;
Atrioventricular (AV) valves shut to stop backflow ;
relaxation / diastole, of ventricles (and atria) ;
semilunar, valves shut to stop backflow ;

19. Pressures changes in the aorta, left ventricle and left atrium during one
heartbeat
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20. Week 8
Describe how heart action is coordinated with reference to the sinoatrial node, the atrioventricular node and the Purkyne tissue.
Interpret and explain electrocardiogram (ECG) traces with reference to normal and abnormal heart activity.
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21. The pathway followed by the wave of excitation
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22. A normal ECG trace compared with others indicating an unhealthy heart
Week 8
A normal ECG trace compared with others indicating an unhealthy heart
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