1. Heart, blood & circulation
Circulatory System
Heart, blood & circulation

2. P.g. 241 Monitoring your pulse

3. Circulatory system Unicellular do not need a circulatory system
Diffusion
E.g. protozoans
Simple multicellular organisms (2 body layers) do not need
E.g. sponges, jellyfish
gases diffuse directly into surrounding environment
No middle layer, both inside & outside are in contact with the environment

4. Challenges
Organisms with mesoderm (middle layer) need a system to circulate materials throughout their complex bodies
E.g. insects, all vertebrates
Cells in the mesoderm will not be in contact with oxygen & nutrients directly from the environment

5. Functions Carries nutrients to cells Carries waste away
Carries chemical messages (hormones)
Distributes heat
Maintains level of body fluid
Transports immune cells
Carries Oxygen from the lungs to cells

6. Open vs Closed Open Circulatory System Closed Circulatory System
Blood is pumped into open body cavities
Comes into direct contact with cells
Low-pressure
E.g. snails, insects, crustaceans
Closed Circulatory System
Blood is contained in blood vessels
Separated from extracellular fluid
High-pressure
E.g. earthworms, squid, humans

8. 3 Major Parts Blood – carries materials through the body
Blood vessels – routes blood travels
Heart – pumps (pushes) blood through the body

9. Blood 45%: erythrocytes (red blood cells)
Have hemoglobin proteins, carry 02

10. Blood <1%: leukocytes (white blood cells)
Function in immune responses
Some: destroy microbes using phagocytosis
Some: produce antibodies

11. Blood 55%: plasma (fluid)
Contains: proteins, water, vitamins, minerals, gases, waste, platelets (function in blood clotting)

12. Blood Vessels Blood vessels are one-way streets
Arteries – carry blood away from the heart
High pressure, strong, elastic

13. Blood Vessels Veins – carry blood back to the heart
Lower pressure, weaker
Valves keep blood moving in the correct direction (often against gravity)

14. Blood Vessels
Capillaries – connect arteries and veins, site of fluid and gas exchange between blood & body cells
Network
Thin & fragile

15. Similarly to the activity we did on p. g
Similarly to the activity we did on p.g.241 You must design an experiment to relate blood pressure to physical activity.
Use the outline provided.
Be sure you use compile and organize your data using appropriate formats. (tables, data, etc.)

17. Look at figure 2 on page 257 and label your heart picture.
What are all these words? :p

18. Heart (mammals) 4 chambers
Right atrium (top)
Right ventricle (bottom)
Left atrium (top)
Left ventricle (bottom)
Valves between chambers ensure one-way blood flow
Covered by the pericardium – bag filled with fluid that reduces friction between the heart and other tissues as it expands and contracts

20. Two pathways of circulation
Pulmonary Circulation – eliminates CO2 and oxygenates blood (lung pathway)

21. Two pathways of circulation
Systemic Circulation – delivers blood to all body cells and carries away waste (body pathway)

22. “Double Loop”

23. Path of Blood through the Heart
Deoxygenated blood enters right atrium through the vena cava

24. Path of Blood through the Heart
Blood passes through the tricuspid valve into the right ventricle

25. Path of Blood through the Heart
Blood passes through the pulmonary valve, into the pulmonary arteries and heads to the lungs

26. Path of Blood through the Heart
Blood returns from the lungs via the pulmonary veins and enters the left atrium

27. Path of Blood through the Heart
Blood passes through the bicuspid valve into the left ventricle

28. Path of Blood through the Heart
Oxygenated blood passes through the aortic valve into the aorta and heads to the body