1. Functions of Human Circulatory System Chp. 8 Includes transport of: 1. oxygen 2. carbon dioxide 3 nutrients 4. water 5. ions 6. hormones 7. antibodies 8. metabolic wastes

2. The Human Circulatory System • 4 chambered heart • Arteries • Capillaries • Veins

4. Arteries • muscular vessels carrying blood away from heart • carry oxygenated blood • Exception- pulmonary artery (to lungs)

5. Capillaries • thin walled (one cell layer) vessels • arise from arterioles (tiny arteries) • form capillary beds • all exchange between blood & cells occurs here

6. Veins • Venules receive blood from the capillaries • Low oxygenated blood transferred to veins • Veins carry low O2 blood to heart • Exception- pulmonary vein carries oxygenated blood • Thin walled & flattened • Nearer to body surface than arteries

7. Circulation Through Human Heart Body blood enters RIGHT SIDE of HEART Right atrium ----> right ventricle ----> Pulmonary artery ----> alveoli inlungs----> oxygenated blood --> Pulmonary Veins ----> Left Atrium. ----> Left Ventricle ----> blood leaves through Aorta (first artery) ---> flows to body

9. Control of the Heart • Extrinsic (outside) • Intrinsic (within)

10. Extrinsic (outside) control of heart beat • autonomic nervous system • adrenal hormone epinephrine • heart itself can secrete regulatory hormones when changes in blood pressure in the atria are detected.

11. Intrinsic (within) control • Origin of heart beat • Sinoatrial (SA) node ( pacemaker) • May be influenced by autonomic nervous system

12. Human Circulatory System Circuits • Hepatic Portal Circuit • Renal Circuit • Cardiac Circuit • Systemic Circuit

13. Capillaries • composed of interlocking cells • one cell thick • nutrients, ions, water, & oxygen diffuse here • Blood moves from capillary to a venule, picks up: • ions • Water • carbon dioxide • metabolic wastes • nutrients from intestine Materials leave capillaries by three mechanisms: 1. Diffusion 2. Hydrostatic pressure 3. Pinocytosis

14. Veins • Entering blood volume equals that leaving arteries • blood pressure is much lower than in arteries

15. Movement through veins assisted by: • one way flap-like valves allow blood to move in one direction (toward heart) • some smooth muscle around larger veins that contracts and moves blood • limb and breathing movements literally massages veins and squeezes blood along

16. Arterioles and Capillaries Figure 8.2

17. Capillary Structure Figure 8.4

18. Lymphatic System • Function: maintain blood volume; also functions in immune system • Structure • Blind-ended capillaries • Lymphatic vessels • Lymph

19. The Heart Figure 8.8

20. The Heart • Structure • Layers; epicardium, myocardium, endocardium • Chambers: two atrias, two ventricles • Valves • Two atrioventricular valves: tricuspid and bicuspid (mitral) • Two semilunar valves: pulmonary and aortic

21. Pulmonary Circuit: Oxygenation of Blood • Deoxygenated blood through the vena cava to the right atrium • Deoxygenated blood through the right atrioventricular valve to the right ventricle • Deoxygenated blood through the pulmonary semilunar valve to the pulmonary trunk and the lungs • Oxygenated blood through the pulmonary veins to the left atrium • Oxygenated blood through the left atrioventricular valve to the left ventricle

22. Systemic Circuit: Delivery of Oxygenated Blood to Tissues and Return of Blood to the Heart • Oxygenated blood through the aortic semilunar valve to the aorta • Oxygenated blood through branching arteries and arterioles to the tissues • Oxygenated blood through the arterioles to capillaries • Deoxygenated blood from capillaries into venules and veins • Ultimately to the vena cava and into the right atrium

23. Cardiac Cycle Figure 8.12

24. Heart Sounds and Heart Valves • Lub-dub • Heart murmurs

25. Cardiac Conduction System Coordinates Contraction • SA node: cardiac pacemaker • AV node: relay impulse • AV bundle and Purkinje fibers: carry impulse to ventricles Figure 8.14

26. Electrocardiograms (EKG/ECG) • Three formations • P wave: impulse across atria • QRS complex: spread of impulse down septum, around ventricles in Purkinje fibers • T wave: end of electrical activity in ventricles • Arrythmias, ventricular fibrillation

27. Electrocardiograms (EKG/ECG) (cont.) Figure 8.15B, C

28. Blood Pressure • Definitions: “normal” • Systolic pressure • Diastolic pressure • Measurement: sphygmomanometer

29. Blood Pressure • Hypertension: high blood pressure • Definition • The silent killer • Risk factors • Hypertension: blood pressure too low • Clinical signs: dizziness, fainting • Causes: orthostatic, severe burns, blood loss

30. Regulation of the Cardiovascular System: Baroreceptors • Baroreceptors: pressure receptors in aorta andcarotid arteries • Steps in mechanism • Blood pressure rises, vessels stretched • Signals sent to brain in the cardiovascular center • Heart signaled to lower heart rate and force of contraction • Arterioles vasodilate, increasing blood flow to tissues • Combined effect lowers blood pressure

31. Regulation of the Cardiovascular System: Nervous and Endocrine Factors • Medulla oblongata signals • Sympathetic nerves: constrict blood vessels, raising blood pressure • Parasympathetic nerves: dilate blood vessels, lowering blood pressure • Hormones: epinephrine (adrenaline) • Local requirements dictate local blood flow

32. Cardiovascular Disorders • Angina pectoris: A warning • Myocardial infarction/heart attack: permanent cardiac damage • Congestive heart failure: decrease in pumping efficiency • Embolism: blockage of blood vessels • Stroke: impaired blood flow to the brain

33. Reducing the Risk of Cardiovascular Disease • Smoking: Don’t • Blood lipids: monitor cholesterol levels • Exercise: regular and moderate • Blood pressure: treat hypertension • Weight: being overweight increases risk of heart attack and stroke • Control of Diabetes Mellitus: early diagnosis and treatment delays onset of related problems • Stress: avoid chronic stress

34. Cardiac Anatomy Quiz 2 1 4 6 3 7 5 8 13 9 14 10 11 12 15 Test Yourself, page 172

35. Blood • Connective tissue • plasma matrix + 3 types cells Plasma = 90% water + 10% plasma solids. Solids include: urea amino acids glucose hormones ions fats proteins

36. The 3 Major Blood Proteins albumins - large proteins that bind impurities & some toxins, aid in transport of hormones, fatty acids and ions, help maintain osmotic balance. globins - include antibodies (immunoglobins) fibrinogen - important in blood clotting

37. Blood Cells • Erythrocytes • Leukocytes • Platelets

38. Erythrocytes (red blood cells) • small, disk-like shape • no nucleus • cannot reproduce • last 4 months then rupture • produced by red bone marrow • contain hemoglobin • carry oxygen

39. Leukocytes (white blood cells) • Nucleus present • Active in immune system • most are neutrophils that engulf microorganisms • Basophils • Eosinophils • lymphocytes

40. Platelets (thrombocytes) • tiny • numerous • cell fragments • aid blood clotting

41. Circulatory system + lymphatic system = Proper Osmotic Conditions

42. Three Fluid Regions Of Body 1) fluid of blood and lymph 2) interstitial fluid - watery fluid between and among cells 3) intracellular fluid