1. Circulatory Systems

3. Exchange of materials
Animal cells exchange material across their cell membrane
fuels for energy
nutrients
oxygen
waste (urea, CO2)

4. Exchange of materials If you are a 1-cell organism that’s easy!
If you are many- celled that’s harder

5. What needs to be transported
Nutrients & Fuels: from digestive system
Respiratory Gases: O2 & CO2 from & to gas exchange systems: lungs, gills
Intracellular Waste: waste products from cells {water, salts, nitrogenous wastes (urea)}

6. Protective Agents
immune defences: white blood cells & antibodies
blood clotting agents
Regulatory Molecules: hormones

7. Circulatory Systems All animals have: circulatory fluid = “blood”
tubes = blood vessels
muscular pump = heart

9. Open circulatory system
Invertebrates: insects, arthropods, mollusks
Structure
no separation between blood & interstitial fluid
hemolymph

10. Closed circulatory system
Invertebrates: earthworms, squid, octopuses
Vertebrates

11. Closed circulatory system
Structure:
blood confined to vessels & separate from interstitial fluid
1 or more hearts
large vessels to smaller vessels
material diffuses between vessels & interstitial fluid

12. Vertebrate cardiovascular system
Chambered heart
atrium = receive blood
ventricle = pump blood out

13. Heart Structure
The wall separating the left and right sides of your heart is known as the septum.

14. Heart Structure
Each side has a thin walled atrium to collect blood above a more muscular ventricle that pumps blood.

15. Heart Structure
Between the different regions of the heart are valves to ensure blood only flows in one direction.

16. Mammalian Heart

17. Vertebrate cardiovascular system
Blood vessels
arteries = carry blood away from heart, arterioles
veins = return blood to heart, venules
capillaries = point of exchange, thin wall, capillary beds = networks of capillaries

18. Arteries
Arterioles
Capillaries
Venules
Veins

19. Two Systems in One
The left and right side of your heart do different functions.
The right side of your heart pumps blood to the lungs to exchange CO2 for O2 in the pulmonary circuit.

20. Two Systems in One
The left side of your heart pumps oxygen rich blood around your body in the systemic circuit.
Blood moving through the heart is the cardiac circuit.

21. Mammalian Circulation
Systemic Circulation
Pulmonary Circulation
Pulmonary Circulation
Systemic Circulation

22. Heart Valves 4 valves in the heart flaps of connective tissue
prevent backflow

23. Heart Valves Atrioventricular (AV) valve between atrium & ventricle
keeps blood from flowing back into atria when ventricles contract
“lub”

24. Heart Valves Semilunar valves between ventricle & arteries
prevent backflow from arteries into ventricles while they are relaxing
“dub”

25. Heart Sounds
The heart beat is actually controlled within the heart itself by two bundles of nerves.

26. Heart Sounds
The sinoatrial (SA) node acts as a pacemaker causing the atria to contract while the atrioventricular (AV) node ensures the ventricles contract a moment later.

27. Lub-dub, lub-dub closing of valves
“Lub”: recoil of blood against closed AV valves
“Dub”: recoil of blood against semilunar valves
Heart murmur
defect in valves causes hissing sound when stream of blood squirts backward through valve

28. Cardiac cycle 1 complete sequence of pumping heart contracts & pumps
heart relaxes & chambers fill

29. Cardiac cycle contraction phase systole: ventricles pumps blood out
relaxation phase
diastole: atria refill with blood