1. Topic 6.2 + Option H5 Transport System IB Biology

2. Components of Transport System Blood Heart Blood Vessels

3. Types of Circulation 1) Pulmonary heart – lungs – heart 2) Systemic heart – body – heart

4. Types of Circulation 3) Coronary blood vessels that supply heart muscle with oxygen and nutrients / remove waste products

5. Blood Plasma – fluid Red blood cells or erythrocytes – produced in the bone marrow of large bones / transport O2 and CO2 White blood cells (lymphocytes and phagocytes) – produced in the bone marrow / belong to immune system Platelets - cell fragments that help blood clotting

6. (antibodies) urea + HEAT

10. left: to receive + pump blood to the body2 types of chambers: atrium + ventricle 4 chambers: 2 atria/2 ventricles Cardiac muscle: involuntary Ultimate control: Autonomic Nervous System (ANS)

11. Heart Structure

12. Blood Vessels Arteries carry blood Away from heart; strong thick walls; smooth muscle (elastic); fibrous coat; small lumen = ↑ pressure Veins carry blood back to heart; large lumen; thin wall/muscle; ↓ elastic; valves Capillaries connect arteries and veins; no valves; pores; no muscle/not elastic extremely thin (1 cell thick) = fast exchange

13. Blood Pressure Blood applies pressure to the walls If it is too low - cells might not get enough O2 If it is too high - vessels can rupture (heart attack, stroke) Salt can increase blood pressure Normal blood pressure: 120/80 mm Hg

14. Coronary Heart Disease Slow build up of plaque (lipids, cholesterol) = ATHEROSCLEROSIS Arteries become harder, less flexible Less space for blood Coronary arteries supply O2 to heart cells Thrombosis = clot = heart attack = heart cells die Factors affecting coronary heart disease (CHD): Age, race, heredity, gender, cholesterol levels, blood pressure, obesity, diabetes, smoking, sedentary lifestyle, stress

17. Impulse spreads to both atria → atria contract together

18. Atrio-Ventricular node (AVN) picks up the impulse in lower right atrium septum and conduces to the ventricles through fibers

19. Ventricles contract: AV valves close / semi-lunar valves open (SISTOLE)

21. Exercise = ↑CO2 / ↓O2 = medulla oblongata (brainstem) takes over

22. Chemoreceptors detect ↑CO2 = H+ causes decrease in pH

24. Cardiac Cycle One whole heartbeat Sistole = contraction / Diastole = relaxation Valves prevent backflow Sound = valves closing 1st = atrio-ventricular valves (mitral, tricuspid) 2nd = semilunar valves (aortic, pulmonary) Important = valves open and close depending on pressure inside chambers/blood vessels Atria systole = pressure not too great (thin walls, most blood already moved to ventricles) Ventricular systole = pressure great inside both ventricles