Bio1.5 Life processes related to a mammal as a consumer Part Two: Blood circulation

1. Bio1.5 Life processes related to a mammal as a consumer Part Two: Blood circulation (transport of products of digestion within the body)

2. Why do we need blood circulation? • Organ system consisting of heart (pump), vessels (veins, arteries, arterioles, capillaries) • transports • Oxygen (from lungs) to the cells that need it for respiration (to produce energy) • Glucose (from small intestine) to the cells that need it for respiration (to produce energy) • Other molecules (food, hormones) that have been packaged by the liver • Wastes such as carbon dioxide to the lungs for exhalation, uric acid to the kidneys. • Transport of heat.

3. Components of blood: • 1. Red Blood Cells • Disc shaped, no nucleus • Contains Haemoglobin that binds to oxygen. Picks up oxygen where concentration is high and drops oxygen off where concentration in low. • Life span: 4 months (dies, broken down, iron stored in liver) • Made in bone marrow (ribs / breast bone)- EPO stimulate RBC production

4. Components of blood: • White Blood Cells • Also called leucocytes • Some engulf / eat / destroy bacteria at infection sites or in blood • Other produce antibody to inactivate pathogens • Made in red marrow of bones

5. Components of blood: • Platelets • Help clot blood to stop bleeding at wounds • Made when pieces of cytoplasm bud off larger cells • Plasma • Liquid part of blood, straw coloured • Carries dissolved substances (salts, + products of digestion: amino acids, glucose, + wastes (urea, CO2) + hormones (eg adrenalin) • Carries plasma proteins (for clotting), antibodies (for protection against pathogens)

6. *Components of Blood Red Blood Cells • Disc shaped, no nucleus • Haemoglobin pigment binds to oxygen weakly (oxygen released in tissue where oxygen is low) • Life span: 4 months (dies, broken down, iron stored in liver) • Made in bone marrow (ribs / breast bone) White Blood Cells • Also called leucocytes • Some engulf / eat / destroy bacteria at infection sites or in blood • Other produce antibody to inactivate pathogens • Made in red marrow of bones Platelets • Help clot blood to stop bleeding at wounds • Made when pieces of cytoplasm bud off larger cells Plasma • Liquid part of blood, straw coloured • Carries dissolved substances (salts, + products of digestion: amino acids, glucose, + wastes (urea, CO2) + hormones (eg adrenalin) • Carries plasma proteins (for clotting), antibodies (for protection against pathogens)

7. The journey of a drop of blood: Imagine you are observing the journey of a drop of blood that’s about to enter a villus to pick up nutrients, write a few sentences for each stage of its journey through the body, the highs and lows, happiness and tears... You can use textbooks, videos and other things to help you, a good place to start is the diagram on pg114 of the life study text book. (pg115 and 116 also very useful). Be sure to include what happens in the intestines, liver, veins, lungs, capillaries, heart, arteries and muscle cells. (e.g. loss/gain of substances?) Questions: Look at the structure of arteries and veins: what are the functions of artery, vein and capillary? why do arteries have much thicker walls? And veins with a bigger diameter? Why are the walls of capillaries so thin? Why don’t all arteries carry oxygenated blood and all veins carry deoxygenated blood. What gives the blood pressure to move around the body? Why is CO2 produced by cells? What’s the function of valves in your veins?

8. Questions: Name the four major components of blood and identify the major function of each. Identify the functions of the blood circulatory system. By what process do nutrients and oxygen from the blood get into the body cells?

9. Circulation: The picture shows the pulmonary (lungs) arteries and veins.

10. The three main parts of the circulatory system are heart, blood vessels and blood. And there are 3 types of blood vessels. They are artery, vein and capillary. Arteries carry blood away from the heart, veins carry blood towards the heart. Capillaries are the site where exchange of nutrients and oxygen happen.

11. 5 um 18 mm 30mm Arteries have pretty thick walls because it needs to sustain high pressure exerted by the heart, capillaries are a thousand times smaller than arteries and veins and that their cell wall is only one cell thick, and therefore very leaky which means that nutrients and oxygen from the blood can be passed to the cells.

12. However not all the fluid that get out of the blood returns to the blood, some are moved to another route called the lymph vessel, which has lymph nodes which has white cells that cleanses the blood and the fluid is returned to the vein later on.

15. *Heart Exterior http://wikieducator.org/The_Anatomy_and_Physiology_of_Animals/Heart_Worksheet

16. *Heart Interior

17. *Heart Interior (v2)

18. Blood Loss* Four classes: • Class I Hemorrhage involves up to 15% of blood volume. There is typically no change in vital signs. • Class II Hemorrhage involves 15-30% of total blood volume. A patient is often tachycardic (rapid heart beat). The body attempts to compensate with peripheral vasoconstriction. Skin may start to look pale and be cool to the touch. The patient may exhibit slight changes in behaviour. Saline solution is all that is typically required. Blood transfusion is not typically required. ABL about here (33%). ABL = allowable blood loss • Class III Hemorrhage involves loss of 30-40% of circulating blood volume. The patient's blood pressure drops, the heart rate increases, shock, capillary refill worsens, and the mental status worsens. Saline solution and blood transfusion are usually necessary. • Class IV Hemorrhage involves loss of >40% of circulating blood volume. The limit of the body's compensation is reached and aggressive resuscitation is required to prevent death.

19. Blood* • How much & how much can I lose? • Allowable blood loss calculator^ (amount you can lose before you need a transfusion) and estimate of total volume: http://www.manuelsweb.com/blood_loss.htm • NB: The hematocrit (Ht or HCT) or packed cell volume (PCV) or erythrocyte volume fraction (EVF) is the volume percentage (%) of red blood cells in blood. It is normally about 45% for men and 40% for women. • ^ who would need to know this? Why?

20. Questions • Why do arteries have thick walls whereas veins have thin walls? • What’s the function of valves in the veins? • What gives high pressure to the blood? • Choose the correct: Ateries carry blood away/to the heart. Veins carry blood away/to the heat.