1. Circulation and Respiration Chapter 22

2. Up in Smoke Most new smokers are under age 15 Smoking damages circulatory and respiratory systems Smokers increase risk of respiratory infections, cancers, high blood pressure, stroke, and heart attack

3. Impacts, Issues Video Up In Smoke

4. The Circulatory System Works with other organ systems Maintains volume, solute concentration and temperature of interstitial fluid Interstitial fluid and blood are body’s internal environment

5. Blood Circulation Blood flows through blood vessels Heart generates force to keep blood moving Closed system –Blood is confined to vessels and heart Open system –Blood mingles with fluid in tissues

6. Types of circulatory systems Circulatory Systems

7. Blood Flow and Gas Exchange Rate of blood flow varies with diameter of blood vessels Slowest flow in smallest vessels, the capillaries Gases are exchanged between blood and interstitial fluid across capillary walls

8. Vertebrate Circulatory Systems Fish –Two-chambered heart, one circuit Amphibians –Three-chambered heart, two partially separate circuits Birds and mammals –Four-chambered heart, two entirely separate circuits

9. Circulatory systems Circulatory Systems

10. Double Circuits In birds and mammals Right half of heart –Pulmonary circuit –Heart to lungs and return Left half of heart –Systemic circuit –Heart to body tissues and return

11. Functions of Blood Transports oxygen and nutrients to cells Carries carbon dioxide and wastes away from cells Helps stabilize internal pH Carries infection-fighting cells Helps equalize temperature

12. Components of Blood Plasma –Water –Proteins –Dissolved materials Cells –Red blood cells –White blood cells –Platelets

13. red blood cell white blood cell platelets Fig. 22-3a, p.363

14. Erythrocytes (Red Cells) Most numerous cells in blood Transport oxygen and carbon dioxide Colored red by oxygen-binding pigment (hemoglobin) Have no nucleus when mature

15. Leukocytes (White Cells) Function in housekeeping and defense Cell types BasophilsDendritic cells EosinophilsB cells NeutrophilsT cells Macrophages

16. Platelets Membrane-bound cell fragments Derived from megakaryocytes, which arise from stem cells Release substances that initiate blood clotting

17. Human Heart Is a Double Pump Partition separates heart into left and right sides Each pumps blood through a different circuit

18. Pulmonary Circuit Heart to lungs Oxygenates blood right pulmonary arteryleft pulmonary artery capillary bed of right lung pulmonary trunk capillary bed of left lung (to systemic circuit) pulmonary veins lungs (from systemic circuit) heart

19. Systemic Circuit Starts at aorta Carries oxygenated blood to body tissues capillary beds of head and upper extremities (to pulmonary circuit) aorta (from pulmonary circuit) heart capillary beds of other organs in thoracic cavity capillary bed of liver capillary beds of intestines capillary beds of other abdominal organs and lower extremities

20. Human blood circulation Blood Circulation

21. Four Chambers Each side has two chambers –Upper atrium –Lower ventricle Valves between atria and ventricles

22. Heart Anatomy superior vena cava right semilunar valve right pulmonary veins right atrium right AV valve right ventricle inferior vena cava septum myocardium heart’s apex arch of aorta trunk of pulmonary arteries left semilunar valve left pulmonary veins left atrium left AV valve left ventricle endothelium and connective tissue inner layer of pericardium Major Vessels

23. The human heart The Human Heart

24. Cardiac Cycle Diastole (mid to late). Ventricles fill, atria contract. Diastole (early). Both chambers relax. Ventricular systole (atria are still in diastole). Ventricles eject.

25. Cardiac cycle Cardiac Cycle

26. Conduction and Contraction SA node in right atrium is pacemaker Electrical signals cause contraction of atria Signal flows to AV node and down septum to ventricles SA node

27. Blood Vessels Arteries: carry blood away from heart Arterioles: diameter is adjusted to regulate blood flow Capillaries: diffusion occurs across thin walls

28. Blood Pressure Highest in arteries, lowest in veins Usually measured in the brachial artery Systolic pressure is peak pressure –Ventricular contraction Diastolic pressure is the lowest pressure –Ventricular relaxation

29. Measuring Blood Pressure

30. Hypertension Blood pressure above 140/90 Tends to be genetic May also be influenced by diet Contributes to atherosclerosis “Silent killer”, few outward signs

31. Atherosclerosis Arteries thicken, lose elasticity Fill up with cholesterol and lipids High LDL increases risk

32. Atherosclerosis in arteries of heart Causes heart attacks Coronary Artery Disease

33. Risk Factors SmokingGenetics High cholesterolHigh blood pressure ObesityDiabetes AgeGender

34. Respiratory System Works with the circulatory system to deliver oxygen and remove carbon dioxide Also helps regulate acid-base balance

35. Respiration –Physiological process by which oxygen moves into an animal’s internal environment and carbon dioxide moves out Aerobic respiration –Cellular process, produces ATP –Oxygen is used –Carbon dioxide is produced

36. Factors In Gas Exchange Surface-to-volume ratio –Small, flat animals Ventilation –Adaptations enhance exchange rate Respiratory pigments –Hemoglobin and myoglobin

37. Surface-to-Volume Ratio As animal size increases, surface-to- volume ratio decreases Small, flat animals can use the body surface as their respiratory surface Larger animals have special structures to increase respiratory surface, such as gills or lungs

38. Human Respiratory System pharynx (throat) larynx (voice box) trachea (windpipe) pleural membrane intercostal muscle diaphragm epiglottis Bronchiole Alveoli

39. NASAL CAVITY PHARYNX (THROAT) EPIGLOTTIS LARYNX (VOICE BOX) TRACHEA (WINDPIPE) LUNG (ONE OF A PAIR) BRONCHIAL TREE PLEURAL MEMBRANE ORAL CAVITY (MOUTH) INTERCOSTAL MUSCLES DIAPHRAGM Fig. 22-21a, p.374

40. bronchiole alveolar duct alveoli alveolar sac (sectioned) Fig. 22-21b, p.374

41. alveolar sac pulmonary capillary Fig. 22-21c, p.374

42. Human respiratory system Human Respiratory System

43. Breathing Moves air into and out of lungs Occurs in a cyclic pattern called the respiratory cycle One respiratory cycle consists of inhalation and exhalation

44. Inhalation Diaphragm flattens External intercostal muscles contract Volume of thoracic cavity increases Lungs expand Air flows down pressure gradient into lungs

45. Normal (Passive) Exhalation Muscles of inhalation relax Thoracic cavity recoils Lung volume decreases Air flows down pressure gradient and out of lungs

46. Respiratory Cycle Respiratory cycle

47. red blood cell air space inside alveolus pore for airflow between alveoli Cutaway View of Alveolus (see next slide)

48. Respiratory Membrane Area between an alveolus and a pulmonary capillary Oxygen and carbon dioxide diffuse across easily alveolar epithelium capillary endothelium fused basement membranes of both epithelial tissues

49. Oxygen Transport Most oxygen is bound to heme groups in hemoglobin in red blood cells Hemoglobin has higher affinity for oxygen when it is at high partial pressure (in pulmonary capillaries) Lower affinity for oxygen in tissues, where partial pressure is low

50. Control of Breathing Nervous system controls rhythm and magnitude of breathing Breathing is adjusted as a result of changes in –Carbon dioxide levels –Oxygen levels –Blood acidity

51. Bronchitis Irritation of the ciliated epithelium that lines bronchiole walls Caused by air pollutants, smoking, or allergies Excess mucus causes coughing, can harbor bacteria Chronic bronchitis scars and constricts airways

52. Emphysema Irreversible breakdown of lung tissue Lungs become inelastic May be caused by a genetic defect Most often caused by smoking

53. Emphysema

54. Effects of Smoking Shortened life expectancy Increased rate of cancers Increased rate of heart disease Impaired immune function and healing Harmful to fetus

55. Heimlich Maneuver