2. Human Respiratory System

3. How it works. The simple task of the respiratory system is to supply the blood cells with oxygen.

4. When we breathe. Respiration is achieved through the mouth, nose, trachea, lungs and diaphragm. Oxygen then enters through the mouth and nose. Oxygen cell.

5. Organization of the Respiratory System The respiratory system is divided into the upper respiratory system, above the larynx, and the lower respiratory system, from the larynx down

6. Components of the Respiratory System Figure 23–1

7. The Respiratory Tract Consists of a conducting portion: from nasal cavity to terminal bronchioles Consists of a respiratory portion: the respiratory bronchioles and alveoli - Are air-filled pockets within the lungs where all gas exchange takes place

8. Image of the Respiratory System

9. Figure 23.3c Figure 23.3 The Nose, Nasal Cavity, and Pharynx

12. Bronchi – the two large passageways that lead from the trachea to your lungs (one for each lung) -- the bronchi are further subdivided into bronchioles -- eventually, the further subdivisions lead to tiny air sacs called alveoli -- alveoli are in clusters, like grapes -- capillaries surrounding each alveolus is where the exchange of gases with the blood occurs The diaphragm is the muscle that causes you to breath -- hiccups are involuntary contractions of the diaphragm

13. Figure 23.10a Figure 23.10 The Bronchi and Lobules of the Lung

14. Figure 23.10b Figure 23.10 The Bronchi and Lobules of the Lung

15. Overview Respiration = gas exchange - - Occurs at the levels of the lungs and tissues (external respiration) and cell (internal or cellular respiration). External respiration: - Pulmonary ventilation: movement of air in and out of the lungs -Gas exchange in the alveoli -Gas transport in the blood -Gas exchanges between blood and tissues

16. Respiratory airway: Alveoli Alveolar wall is formed by simple squamous epithelium = type I cells (SSE)  gas exchange Respiratory membrane: membrane separating alveolus from blood capillary. Large surface area from the numerous alveoli  better gas exchange Presence of elastic fibers between alveoli

17. Airways Upper airways: - nose to pharynx Lower airways: - Conducting airway: larynx  bronchioles - Respiratory airway: alveoli

18. Blood supply to the lungs

19. Figure 23.2 Figure 23.2 The Respiratory Epithelium of the Nasal Cavity and Conducting System

20. The Respiratory Defense System Consists of a series of filtration mechanisms Removes particles and pathogens

21. Components of the Respiratory Defense System Goblet cells and mucous glands: produce mucus that bathes exposed surfaces Cilia: sweep debris trapped in mucus toward the pharynx (mucus escalator)

22. Components of the Respiratory Defense System Filtration in nasal cavity removes large particles Alveolar macrophages engulf small particles that reach lungs

23. The Nose Air enters the respiratory system: through nostrils or external nares into nasal vestibule Nasal hairs: are in nasal vestibule are the first particle filtration system

24. The Nasal Cavity The nasal septum: divides nasal cavity into left and right Mucous secretions from paranasal sinus and tears: clean and moisten the nasal cavity Superior portion of nasal cavity is the olfactory region: provides sense of smell

25. Air Flow From vestibule to internal nares: through superior, middle, and inferior conchae

26. The Palates Hard palate: forms floor of nasal cavity separates nasal and oral cavities Soft palate: extends posterior to hard palate divides superior nasopharynx from lower pharynx

27. The Nasal Mucosa Warm and humidify inhaled air for arrival at lower respiratory organs Breathing through mouth bypasses this important step

28. The Pharynx A chamber shared by digestive and respiratory systems Extends from internal nares to entrances to larynx and esophagus

29. Divisions of the Pharynx Nasopharynx Oropharynx Laryngopharynx

30. The Nasopharynx Superior portion of the pharynx Contains pharyngeal tonsils and openings to left and right auditory tubes

31. The Oropharynx Middle portion of the pharynx Communicates with oral cavity

34. The Laryngopharynx Inferior portion of the pharynx Extends from hyoid bone to entrance to larynx and esophagus

35. Anatomy of the Larynx Figure 23–4

36. Cartilages of the Larynx 3 large, unpaired cartilages form the larynx: the thyroid cartilage the cricoid cartilage the epiglottis

37. The Thyroid Cartilage Also called the Adam’s apple Is a hyaline cartilage Forms anterior and lateral walls of larynx Ligaments attach to hyoid bone, epiglottis, and laryngeal cartilages

38. The Cricoid Cartilage Is a hyaline cartilage Form posterior portion of larynx Ligaments attach to first tracheal cartilage

39. The Epiglottis Composed of elastic cartilage Ligaments attach to thyroid cartilage and hyoid bone

40. Cartilage Functions Prevents entry of food and liquids into respiratory tract During swallowing: the larynx is elevated the epiglottis folds back over glottis Thyroid and cricoid cartilages support and protect: the glottis the entrance to trachea

41. The Glottis Figure 23–5

42. Sound Production Air passing through glottis: vibrates vocal folds produces sound waves Sound Variation Sound is varied by: tension on vocal folds voluntary muscles Speech is done at the larynx

43. Anatomy of the Trachea Figure 23–6

44. The Trachea Also called the windpipe Extends from the cricoid cartilage into pulmonary bronchi where it branches into right and left pulmonary bronchi

45. The Tracheal Cartilages 15–20 tracheal cartilages: strengthen and protect airway discontinuous where trachea contacts esophagus Ends of each tracheal cartilage are connected by: an elastic ligament and trachealis muscle

46. The Primary Bronchi Right and left primary bronchi: separated by an internal ridge (the carina) The Right Primary Bronchus Is larger in diameter than the left Descends at a steeper angle

47. NEW SEATS TODAY For all classes (except 2a, 4a, 2b, 3b) TEST ON THE RESPIRATORY SYSTEM next FRIDAY

48. The Lungs Left and right lungs: are in left and right pleural cavities The base: inferior portion of each lung rests on superior surface of diaphragm

49. The Right Lung Has 3 lobes: superior, middle, and inferior separated by horizontal and oblique fissures

50. The Left Lung Has 2 lobes: superior and inferior are separated by an oblique fissure

51. Relationship between Lungs and Heart Figure 23–8

52. Lung Shape Right lung: is wider is displaced upward by liver Left lung: is longer is displaced leftward by the heart forming the cardiac notch

53. A Primary Bronchus Branches to form secondary bronchi (lobar bronchi)

54. Secondary Bronchi Branch to form tertiary bronchi, also called the segmental bronchi

55. Bronchitis Inflammation of bronchial walls: causes constriction and breathing difficulty

56. The Bronchioles Each small bronchi branches into multiple bronchioles Bronchioles branch into terminal bronchioles: 1 tertiary bronchus forms about 6500 terminal bronchioles

57. Alveolar Organization Respiratory bronchioles are connected to alveoli along alveolar ducts Alveolar ducts end at alveolar sacs: common chambers connected to many individual alveoli

58. An Alveolus Has an extensive network of capillaries Is surrounded by elastic fibers

59. Inflammation of Lobules Also called pneumonia: causes fluid to leak into alveoli compromises function of respiratory membrane

60. Mechanics of breathing Boyle’s law: The pressure of a gas in a closed container is inversely proportional to the volume of the container. Air flow in the lungs is driven by the differences in pressure between the atmosphere and the alveoli P.atm is constant  changes in P.alv drive ventilation

61. Gas Pressure and Volume Figure 23–13

62. Atmospheric Pressure The weight of air: has several important physiological effects Boyle’s Law Defines the relationship between gas pressure and volume: As volume decreases, pressure increases In a contained gas: external pressure forces molecules closer together movement of gas molecules exerts pressure on container

63. Figure 23–14 Mechanisms of Pulmonary Ventilation

64. Figure 23–16a, b The Respiratory Muscles

65. Figure 23–16c, d

66. 3 Muscle Groups of Inhalation 1.Diaphragm: contraction draws air into lungs 75% of normal air movement 2.External intracostal muscles: assist inhalation 25% of normal air movement 3.Accessory muscles assist in elevating ribs: sternocleidomastoid serratus anterior pectoralis minor scalene muscles

67. Pleura and negative pressure Pneumothorax: lung collapse due to air entering in the pleural cavity

68. Respiratory Disorders: Chronic Obstructive Pulmonary Disease (COPD) Slide 13.40b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Features of these diseases  Patients almost always have a history of smoking  Labored breathing (dyspnea) becomes progressively more severe  Coughing and frequent pulmonary infections are common

69. Chronic Obstructive Pulmonary Disease (COPD) Slide 13.43 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 13.13

70. Lung Cancer Slide 13.44 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Accounts for 1/3 of all cancer deaths in the United States  Increased incidence associated with smoking  Three common types  Squamous cell carcinoma  Adenocarcinoma  Small cell carcinoma

71. Sudden Infant Death syndrome (SIDS) Slide 13.45 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Apparently healthy infant stops breathing and dies during sleep  Some cases are thought to be a problem of the neural respiratory control center  One third of cases appear to be due to heart rhythm abnormalities

72. Asthma Slide 13.46 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Chronic inflamed hypersensitive bronchiole passages  Response to irritants with dyspnea, coughing, and wheezing

73. Asthma Slide 13.46 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Chronic inflamed hypersensitive bronchiole passages  Response to irritants with dyspnea, coughing, and wheezing

74. Developmental Aspects of the Respiratory System Slide 13.47b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Important birth defects  Cystic fibrosis – oversecretion of thick mucus clogs the respiratory system  Cleft palate

75. Aging Effects Slide 13.48 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Elasticity of lungs decreases  Vital capacity decreases  Blood oxygen levels decrease  Stimulating effects of carbon dioxide decreases  More risks of respiratory tract infection

76. Respiratory Rate Changes Throughout Life Slide 13.49 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Newborns – 40 to 80 respirations per minute  Infants – 30 respirations per minute  Age 5 – 25 respirations per minute  Adults – 12 to 18 respirations per minute  Rate often increases somewhat with old age