Survey of Anatomy & Physiology Chap 13


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Survey of Anatomy & Physiology Chap 13

  1. 1. 13 The Respiratory System: It's a Gas
  2. 2. Respiratory System  Respiratory system's primary function: to transport oxygen from atmosphere to bloodstream to be utilized by cells, tissues, organs for process of cellular respiration, which is necessary to sustain life
  3. 3. Respiratory System  Respiratory system moves 12,000 quarts of air per day in and out of lungs  Respiratory system removes waste gas— carbon dioxide—so it doesn't build up in toxic levels
  4. 4. Cellular Respiration Needs Oxygen  Cellular respiration depends on continuous supply of oxygen, found in abundance in air we breathe  Using oxygen produces carbon dioxide, which would become toxic if allowed to build in bloodstream; must be removed
  5. 5. Cardiopulmonary System  Respiratory system closely related to heart and circulatory system; they are sometimes grouped together as cardiopulmonary system
  6. 6. Anatomy of Respiratory System  Components of respiratory system:  Two lungs that serve as vital organs  Upper and lower airways that conduct gas in and out of the system  Terminal air sacs called alveoli surrounded by network of capillaries that provide for gas exchange
  7. 7. Anatomy of Respiratory System  Components of respiratory system:  Thoracic cage that houses, protects, facilitates function for the system  Muscles of breathing that include the main muscle, the diaphragm, and accessory muscles
  8. 8. Figure 13-1 The various components of the respiratory system Watch Video on “Respiratory System”
  9. 9. Ventilation versus Respiration
  10. 10. Ventilation versus Respiration Ventilation: bulk movement of air into and out of lungs where gas exchange takes place
  11. 11. Ventilation versus Respiration Respiration: process of gas exchange, where oxygen added to blood and carbon dioxide removed
  12. 12. External Respiration versus Internal Respiration
  13. 13. External Respiration versus Internal Respiration External respiration: gas exchange in lungs occurs between blood and air in the external atmosphere
  14. 14. External Respiration versus Internal Respiration Internal respiration: oxygenated blood transported internally via cardiovascular system to cells and tissues; oxygen moves into cells as carbon dioxide removed
  15. 15. Table 13-1 Gases in the Atmosphere Air contains many gases, predominantly nitrogen, which is a support gas that keeps lungs open with its constant volume and pressure
  16. 16. Table 13-1 Gases in the Atmosphere Next highest concentration found in air is oxygen, essential to life; carbon dioxide is found in very small concentrations
  17. 17. Figure 13-2 Contrast of ventilation and external and internal respiration We have reserve of oxygen to last 4 to 6 minutes; after that we will die if we don't get more oxygen
  18. 18. The Airways and Lungs  Respiratory system is series of branching tubes called bronchi and bronchioles
  19. 19. The Airways and Lungs  Airways transport atmospheric gas deep within lungs to small air sacs called alveoli, which represent terminal end of respiratory system
  20. 20. The Airways and Lungs  Each alveolus is surrounded by capillaries; combination called alveolar-capillary membrane; represents connection between respiratory and cardiovascular systems
  21. 21. Structures of Upper Airway
  22. 22. Function of Upper Airway Structures Nose Mouth Larynx Pharynx
  23. 23. Figure 13-3 The upper airway and vocal cords
  24. 24. Upper Airways of Respiratory Tract  While some people breathe through their mouths, we are meant to breathe through our noses  Rigid structure made of cartilage and bone
  25. 25. Upper Airways of Respiratory Tract  Nasal cavity: behind nose, divided into three main regions Vestibular Olfactory Respiratory
  26. 26. Figure 13-4 The nasal regions
  27. 27. Regions of the Nose Three Main Regions
  28. 28. Vestibular Region of Nose  Vestibular region: located inside nostrils and contains coarse nasal hairs that act as first line of defense for respiratory system  These hairs (vibrissae) covered with sebum, greasy substance secreted by sebaceous glands of nose  Sebum helps trap particles; keeps hairs soft and pliable
  29. 29. Olfactory Region of Nose  Olfactory region: located on roof of nasal cavity, allowing air to be held there so it can be sampled
  30. 30. Respiratory Region of Nose  Respiratory region  Air warmed to body temperature and moistened in this region inside nasal cavity, which is lined with mucous membranes and richly supplied with blood  There are three scroll-like bones (turbinates) that split incoming air into three channels, providing more surface area
  31. 31. Respiratory Region of Nose  Respiratory region  Turbinates serve to make incoming air current more turbulent, bringing more air in contact with mucous membranes for warming and moisture, adding 650 to 1,000mLs of water each day to moisten air to 80% relative humidity
  32. 32. Mucociliary Elevator  Cells in epithelial lining of airways of respiratory system are called pseudostratified ciliated columnar cells  Consists of single layer of tall columnlike cells that have nuclei at different heights, giving appearance of two or more layers  Each columnar cell has 200 to 250 cilia on its surface
  33. 33. Mucociliary Elevator  Goblet cells and submucosal glands are interspersed.  Mucus resides as two layers: Cilia reside in sol layer; contains thin, watery fluid that allows them to beat freely Top layer is gel layer that is more viscous and sticky, trapping small particles
  34. 34. Mucociliary Elevator Cilia act as tiny "oars" resting in watery sol layer and beat 1,000 to 1,500 times per minute and propel gel layer and its trapped debris onward and upward about one inch per minute to be expelled
  35. 35. Mucociliary Elevator  In nose, debris-laden secretions pushed toward front of nasal cavity to be expelled through nose  Pseudostratified ciliated columnar epithelium propels gel layer toward oral cavity to be expectorated with cough or swallowed into stomach
  36. 36. The Sinuses  Skull contains air-filled cavities called sinuses that connect to nasal cavity via small passageways  Located around nose and sometimes referred to as paranasal sinuses  Cavities help prolong and intensify sound produced with our voice and helps to lighten weight of head
  37. 37. The Sinuses  Three different sinuses: Frontal, Ethmoid and Maxillary  Sinuses do not exist at birth  Develop as we grow; facial features changes influenced by sinuses as we mature  Sinuses also help to warm and moisturize air
  38. 38. Pharynx: Three Parts  Pharynx, or throat, is hollow muscular structure beginning behind nasal cavity, lined with epithelial tissue  Pharynx can be divided into three sections  Nasopharynx  Oropharynx  Laryngopharynx
  39. 39. Figure 13-7 The nasopharynx, oropharynx, and laryngopharynx and related structures
  40. 40. First Part: Nasopharynx  Nasopharynx is uppermost section, beginning behind nasal cavity  Section contains lymphatic tissue called adenoids; passageways into middle ear called Eustachian tubes  Air from nasal cavity passes through nasopharynx
  41. 41. Second Part: Oropharynx  Oropharynx is located behind oral, or buccal, cavity  Conducts not only atmospheric gas but also food and liquid  Air breathed through both nose and mouth passes through here, and anything that is swallowed
  42. 42. Second Part: Oropharynx  Tonsils are part of lymph system  Palatine tonsils are located in oropharynx, as are lingual tonsils located at back of tongue  During swallowing, uvula and soft palate move in posterior and superior position to protect nasopharynx and nasal cavity from entry of food or liquid; can be overcome by forceful laughing
  43. 43. Third Part: Laryngopharynx  Laryngopharynx is lowermost portion of pharynx  Air breathed and/or swallowed passes through laryngopharynx  Swallowed materials pass through esophagus to get to stomach  Air travels through larynx and trachea on its way to lungs
  44. 44. The Larynx  Semi rigid structure composed of cartilage connected by muscles and ligaments that provide movement of vocal cords to control speech  “Adam's apple” (thyroid cartilage) is largest of cartilages found in larynx
  45. 45. The Larynx and Glottis  Cricoid cartilage lies beneath it, providing structure and support for airways so they do not collapse  Glottis is opening that leads into larynx and eventually lungs
  46. 46. The Epiglottis  Leaf-shaped flap like fibrocartilage  Closes over opening to larynx when you swallow; opens up when you breathe, as part of swallowing reflex (glottic or sphincter mechanism)  Seals so food does not enter lungs
  47. 47. Figure 13-8 The upper airway and related infections
  48. 48. Vocal Cords as Dividing Line  Vocal cords act as dividing line between upper and lower airways  Lower airway starts below vocal cords  Upper airway ends at vocal cords
  49. 49. Respiratory Diseases Complete the Respiratory Diseases Worksheet Due Thursday Nov 12, 2013 Also due: Take home quiz on Anatomy of the Heart
  50. 50. The Lower Respiratory Tract  Resembles upside-down tree, sometimes called tracheobronchial tree  From vocal cords, air enters trachea, or windpipe, 4½˝ long tube lined with ciliated mucous membrane
  51. 51. The Trachea and Esophagus  C-shaped cartilage found in anterior portion of trachea provide rigidity and protection for exposed airway in neck  Esophagus lies in area where C opens up posteriorly; room for esophagus to expand when you swallow larger chunks of food
  52. 52. Trachea and Mainstem Bronchi  Trachea is largest pipe; can be thought of as trunk of tree  Trachea begins branching (bifurcating) at center of chest into left and right mainstem bronchi (bronchus is singular form)
  53. 53. Trachea and Mainstem Bronchi  Site of bifurcation is called carina  Next bronchi must branch into five lobular bronchi; correspond to five lobes of lungs carina
  54. 54. Bronchi of the Lung  Each lung lobe further divided into specific segments; next branching of bronchi called segmental bronchi  At point from trachea down to segmental bronchi, tissue layers of bronchi are all the same, only smaller, as they branch downward
  55. 55. Figure 13-10 Three Tissue layers in the bronchi • Epithelial layer contains mucociliary escalator • Middle is lamina propria layer which contains smooth muscle, lymph, and nerve tracts • Third layer is protective and supportive cartilaginous layer
  56. 56. Bronchi in Lung Segments  Branching continues to tiny subsegmental bronchi that branch deep within each lung segment  Cartilaginous rings become more irregular and eventually fade away  Closer to gas exchange regions, airways simplify to make it easier for gas molecules to pass through
  57. 57. Bronchi Lead to Bronchioles  Bronchioles average 1 mm in diameter  Cilia, goblet cells, and submucosal glands are almost all gone  There is no gas exchange yet
  58. 58. Terminal Bronchioles Terminal bronchioles mark border between conducting and respiratory zones
  59. 59. Respiratory Bronchiole  Next airways beyond terminal bronchioles are respiratory bronchioles, because some gas exchange occurs here
  60. 60. Alveolar Ducts to Alveoli  Alveolar ducts originate from respiratory bronchioles,  These give way to alveoli
  61. 61. Figure 13-11 Conduction and gas exchange structures and functions
  62. 62. Alveoli and Pulmonary Capillaries  Alveoli are terminal air sacs, surrounded by numerous pulmonary capillaries  Together capillaries and alveoli make up functional unit of lung known as alveolar capillary membrane  Adults have 300–600 million alveoli, with total of 80 square meters (m2) surface area for oxygen molecule to diffuse across into capillaries
  63. 63. Pulmonary Circulation  Blood from right heart entering pulmonary capillaries is high in carbon dioxide and low in oxygen
  64. 64. Gas Exchange at Alveolar Capillary Membrane Gas exchange takes place and pulmonary capillary increases in oxygen concentration before traveling to left heart to be pumped around to tissues
  65. 65. Gas Exchange at Alveolar Capillary Membrane 1. The pressure of oxygen in the alveolus is higher than in the capillary and by SIMPLE DIFFUSION, the oxygen enters the circulatory system
  66. 66. Gas Exchange at Alveolar Capillary Membrane 2. The pressure of carbon dioxide in the capillary is higher than in the alveolus and by SIMPLE DIFFUSION, the CO2 enters the respiratory system and is exhaled
  67. 67. Gas Exchange at Cellular Membrane 3.At the tissue level, the pressure of oxygen in the capillary is higher than in the tissue and by SIMPLE DIFFUSION, the oxygen enters the cell.
  68. 68. Gas Exchange at Cellular Membrane 4.The pressure of carbon dioxide in the cell is higher than in the venule and by SIMPLE DIFFUSION, the carbon dioxide enters the circulatory system
  69. 69. Housing of the Lungs and Related Structures  Lungs reside in thoracic cavity and are separated by region called mediastinum, which contains esophagus, heart, great vessels, and trachea  Breathing in and out causes lungs to move within thoracic cavity
  70. 70. Pleura of the Lungs To prevent irritation of lungs moving against thorax, each lung wrapped in sac or serous membrane called visceral pleura
  71. 71. Pleura of the Lungs  Thoracic cavity and upper side of diaphragm lined with continuation of membrane called parietal pleura
  72. 72. Pleural Space with Fluid Between these two pleural layers is pleural space (intrapleural space), which contains slippery liquid called pleural fluid that reduces friction as individual breathes
  73. 73. The Lungs  Conical-shaped with rounded peaks (apex) extending 1 to 2 inches above clavicle  Base of lungs rest on right and left hemi diaphragm with right lung base a bit higher to accommodate liver Cardiac impression Medial surface of lung has deep, concave cavity that holds heart, called cardiac impression, and is deeper on left side
  74. 74. Hilum of The Lungs Hilum is area where root of each lung is attached, containing main stem bronchus, pulmonary artery and vein, nerve tracts, and lymph vessels
  75. 75. The Lobes of the Lungs  Right lung has three lobes: upper, middle, lower lobes; divided by horizontal and oblique fissures  Left lung has one fissure, oblique fissure, and therefore has only two lobes: upper and lower lobes  Lingula is area of left lung that corresponds with right middle lobe
  76. 76. The Lobes of the Lungs  Left lung has only two lobes because largest part of heart is located in left lung area  Right lung is larger, with 60% of gas exchange occurring here
  77. 77. Figure 13-15 Structures of the thoracic cavity
  78. 78. The Protective Bony Thorax  Bony and cartilaginous frame providing freedom of movement  Protects organs of chest  Includes rib cage, sternum, and thoracic vertebrae to which each rib attaches  Sternum, or breastbone, is centrally located; comprised of manubrium, body, and xiphoid process
  79. 79. The Protective Bony Thorax True ribs (pairs 1– 7): called vertebro sternal; connect to sternum and vertebrae Pairs 8–10: called false ribs or vertebro costal; connect to costal cartilage of superior rib and to thoracic vertebrae
  80. 80. Figure 13-17 The thoracic cage
  81. 81. How We Breathe Respiratory control center is in medulla oblongata which is part of the brain stem and is continuous with the spinal cord
  82. 82. How We Breathe Inspiration: active process in which diaphragm is sent signal via phrenic nerve, causing it to contract and flatten downward, increasing thoracic cavity space
  83. 83. How We Breathe Increase in thoracic cavity volume decreases pressure, creating lower pressure in lungs than outside, allowing air to rush into lungs
  84. 84. Figure 13-18 How we breathe Ease of ventilation is called compliance •High compliance: little effort required to expand lungs •Low compliance: more difficult to expand lungs
  85. 85. How We Breathe Exhalation: passive act; diaphragm relaxes, which decreases amount of space in thoracic cavity; pressure in lungs becomes greater than atmospheric pressure; air is pushed out of lungs
  86. 86. How We Breathe While we can consciously influence breathing rate, Our breathing rate is normally controlled by level of carbon dioxide in blood
  87. 87. How We Breathe  If carbon dioxide levels rise, it means that not enough CO2 is being ventilated  When this occurs, chemoreceptors in medulla oblongata send signals to respiratory muscles to increase rate and depth of breathing
  88. 88. Factors Affecting Breathing Rate
  89. 89. How We Breathe  Accessory Muscles include:  Scalene muscles in neck  Sternocleido mastoid  Pectoralis major  Pectoralis minor
  90. 90. Figure 13-19 The accessory muscles of exhalation Accessory muscles of exhalation assist in more forceful and active exhalation by increasing abdominal pressure
  91. 91. How We Breathe Main accessory muscles of exhalation are abdominal muscles that push up diaphragm or the back muscles that pull down and compress thoracic cage
  92. 92. Emphysema Affects lung compliance: Bronchioles become damaged and wider, allowing air into lungs, increasing compliance but making it much more difficult to breathe out Breathing then requires the use of more accessory muscles
  93. 93. Damage to the Lungs
  94. 94. Figure 13-14 Asthma and emphysema
  95. 95. Figure 13-20 Classes of drugs used to treat respiratory disorders
  96. 96. GAS EXCHANGE Complete the GAS EXCHANGE WORKSHEET IN CLASS Use a RED pencil to represent the direction of the oxygen movement and BLUE for the direction of the carbon dioxide movement