2. The Circulatory System You’ve gotta have heart

3. Some Interesting Facts No cell is further than two cells away from a blood vessel that carries nutrients! Your circulatory system has 96 000 km of blood vessels…strung together they could circle the globe 2.5 times! Your heart is the size of your clenched fist! Your heart beats ~ 30 million times per year! An adult heart pumps nearly 18 173 litres of blood each day! During an average lifetime, the heart pumps enough blood to fill two ocean tankers! The average three year old has 1.1 litres of blood in their body; the average adult has 5 times that!

4. Purpose of the Circulatory System Brings oxygen and nutrients to cells Takes away wastes from cells Relays chemical messages (hormones) Maintains fluid levels Important in immunity

5. Blood Flow Through the Heart

6. Major Arteries

7. Types of Blood Vessels 1.Arteries: Carry blood away from the heart Carry oxygenated blood (except one) Usually at high pressure Thick, muscular walls Branch into smaller “arterioles”

8. Types of Blood Vessels 2. Veins: Carry blood to the heart All but one carry low oxygen blood Less pressure Thin, less muscular walls, and valves to prevent backflow Branch into “venules”

9. Types of Blood Vessels

10. 3. Capillaries: Carry blood from arterioles to venules Form a fine network through cells (capillary bed) No tissue is more than 0.1 mm away from a capillary! 1 cell thick – easy diffusion!

11. Bodyworlds Hey, guess why your face bleeds so much?

12. Bodyworlds

13. Types of Blood Vessels Coronary Arteries: Supply heart muscles with blood!

15. Components of the Blood Blood is composed of water, plasma and blood cells (P. 319) Plasma: The fluid portion of the blood 55% of a blood sample

16. Components of the Blood Red blood cells: Contain hemoglobin (O 2 taxis) No nucleus = more hemoglobin (280 million per RBC) Biconcave form – allows them to fit through capillaries 44.9% of a blood sample

17. Components of the Blood White Blood Cells: Fewer than RBC’s (1:700) Have a nucleus Destroy invading microbes Form antibodies 0.1% of a blood sample

18. Components of the Blood Platelets: For blood clotting Are cell fragments Stick to sharp edges in otherwise smooth vessels

19. Bone Marrow RBCs, WBCs and platelets are all produced in the bone marrow

20. Blood Doping See Page 323

21. Regulating Heart Beat The S.A. (sinoatrial) node, also known as the pacemaker sends an electrical impulse to start the heart contraction. Both atria contract The A.V. (atrioventricular) node then tells the ventricles to contract. Double pump “Lub Dub” is the sound of the valves flapping shut

22. Regulating Heartbeat

23. ECG - Electrocardiogram

24. Blood Pressure 1. Systolic (top number) Normal = 120 mmHg The pressure of blood surging through the artery, causing expansion 2. Diastolic (bottom number) Normal = 80 mmHg Heart rests, blood is still, pressure drops

25. The Circulatory System and Exercise Exercise increases CO 2 content in blood, which leads to higher breathing and heart rates (think HR lab). The benefits of exercise are many: 1. Improved body system functions. 2. Improved blood supply to muscles, organs, tissues, etc. 3. Reduced ‘bad’ cholesterol levels. 4. Improved strength, bone density and self-esteem. 5. Improved oxygen capacity and usage!

26. Circulatory System Problems - Jigsaw Form expert groups! Share info!

27. Circulatory System Technology Nitroglycerine: A drug used to treat angina by dilating the coronary arteries. Bypass surgery: A blood vessel is removed from leg and is used to redirect blood flow around a blocked coronary artery. Angioplasty: A small balloon is inserted through a catheter and inflated in order to reduce the narrowing of an artery. Pacemaker: An artificial device that electrically stimulates the heart to beat

28. Bypass Operation

29. Angioplasty

30. Pacemaker