Medic 14 A&P Chapter 15 notes

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Medic 14 A&P Chapter 15 notes
2013-04-22 08:08:50
Medic 14

Ch 15
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  1. Objective:
    Describe the primary functions of the respiratory system.(pp. 547-478)
  2. 5 Basic functions of the respiratory system
    • Providing a large area fro gas exchange between air and circulating blood.
    • Moving air to and from the gas exchange surfaces of the lungs 
    • Protecting the respiratory surfaces from dehydration and temoerature changes and defending against invading pathogens 
    • producing sounds that permit speech,singing, and non verbal auditory communication 
    • providing olfactory sensations to the CNS for the sense of smell
  3. Major anatomical structures of the respiratory system are
    • the nose (nasal cavity, and paranasal sinuses)
    • Pharynx (throat)
    • larynx(voicebox)
    • trachea (windpipe)
    • bronchi(conducing passageways)
    • alveoli(exchage surfaces)
  4. Respiratory tract
    airways that carry air to and from the exchange surfaces of the lungs
  5. Objective:
    Describe how the delicate respiratory exchange surfaces are protected from pathogens, debris, and other hazards. (pp.548)
  6. Respiratory tract divided into
    • Conducting tract
    • respiratory tract
  7. conducting portion
    entrance of nasal cavity to larger bronchi
  8. respiratory portion
    smallest and most delicate bronchioles and alveoli
  9. Conduction portion also
    filter,warm, and humidify  the air, thereby protect he alveoli from debris ,pathogens,and enviromental extremes.
  10. Objective:
    Relate the respiratory functions to the structural specialzations of the tissues and organs in the respiratory system.(pp.458-560)
  11. Nasal vestibule
    space enclosed with coarse hairs that extend across the tissue of the nostils and guard the nasal cavity from large airborne patricels
  12. Anterior portion of the nasal septum is formed of
    hyaline cartilage
  13. nasal cavity and much of the rest of the respiratory tract are lined by a protective mucous membrane called the
    respiratory mucosa
  14. Pharynx (throat)
    Is shared by the respiratory and digestive system
  15. Pharynx extends from
    the internal nares ad the entrances of the esophagus
  16. Three subdivisions of the pharynx
    • nasopharynx
    • oropharynx
    • laryngopharynx
  17. Nasopharynx
    • connected to the nasal caivity by the internal nares and extends to the posterior edge of the soft palate
    • lined with typical respiratory epithelium
    • contains pharongeal tonsil and entrances to auditory tubes
  18. Oropharynx
    • soft palate to the base of the tongue 
    • palatine tonsils lie in the lateral walls
  19. Laryngopharynx
    • extends between the level of the hyoid bone and entrance to the esophagus
    • stratified squamous epithelium
  20. Glottis
    Inhaled air leaves the pharynx and enters the larynx throguh the glottis
  21. larynx
    • voice box
    • consists of 9 cartilages stabalized by ligaments, skeletal muscles or both
  22. Three larges cartilages of the larynx
    • epiglottis
    • throid cartilage
    • cricoid cartilage
  23. Three pairs of smaller cartilage
    • arytenoid 
    • corniculate
    • cuniform
  24. two pair of ligaments
    • false vocal cords
    • true vocal cords
  25. food or liquid touch the vocal cords....
    the coughing relfex is activated
  26. trachea (windpipe)
    • begins at the 6th cervical vertebra where it attached to the cricoid cartilage 
    • ends at the 5th thoratic vertebra in the mediastium
  27. walls of trachea contain 15 to 20
    trachial cartilages that are c shaped
  28. Each trachial cartilage are connected by an elastic ligament and the
    trachealis muscle, a band of smooth muscle
  29. Sympathetic stimulation
    increases the diameter of the trachea
  30. Bronchi
    • Right/left primary bronchi to
    • broncial tree 
    • secondary bronchi (enter the lobes of lung)
    • secondary bronchi  divide to form 9-10 tertiary bronchi in each lung
  31. When cartilates around the bronchi disapear they are called
  32. Sympathetic innervation leads to
    relaxation of the smooth muscles in the walls of bronchilses causing bronchodilation
  33. Parasympathic innervation
  34. Terminal bronchioles
    supply air to a lobule of the lung
  35. lobule
    segment of lung tissue bounded by tissue partitions  supplied by a single bronchiole and accompanied by brancehs of pulmonary arteries and veins
  36. Aveolar ducts
    openins at the ends of bronchioles
  37. Aveolar sacs
    common chambers connected to multiple individual aveoli
  38. aveolar epithelium consitst of
    thin simple squamous
  39. Avelor marcophages
    phagocttize dust and debris in the lung
  40. Spetal cells
    secrete surfactant onto aveolar surfaces
  41. Respiratory distress syndrome
    • lack of surfactant
    • exhausing effort to inflating the deflated lung
  42. Objective:
    Describe the physical principles that govern the movement of air into the lungs and the diffusion of gasses into and out of the blood( pp.560)
  43. 3 steps of respiration
    • Pulmonary ventilation
    • gas exchange
    • gas transport
  44. Pulmonary ventilation
    physical movement of air into and out of the lungs
  45. Gas exchange
    involves gas diffusion at two sites: across the alveor air spaces and alveolar capillaries, and across the capillary cell membranes between blood and other tissue
  46. Gas transport
    involces transport of O2 and CO2 to and from alveolar capilaries and the capillary beds in other tissues
  47. Hypoxia
    Oxygen staved tissues
  48. Anoxia
    oxygen supply cut off
  49. Objective:
    Describe the actions of respiratory muscles on respiratory movement. (pp.560-565)
  50. Respiratory Cycle
    • Inhalation(inspiration)
    • Exhalation(expiration)
  51. We breath to maintain adequate
    Aveolar ventilation
  52. Diaphram
    • Forms the flood of the thoracic cavity
    •  dome shaped and projects upward into the thoratic cavity compressing the lungs
  53. Rib cage
    elevation of the rib cage increases the volume of the thoratic cavity whereas owereing decreases the volume
  54. Complience
    • indication of the lungs resilience and abilty to expand
    • lower the complience the greater the force required to fill and empty the lungs
  55. Modes of breathing
    • quiet breathing
    • forced breathing
  56. quiet breathing
    • 75% Diaphragm
    • 25% intercostals
    • inhalation involves muscular contraction
    • exhalation is passive
  57. Forced breathing
    • Inhalation and exhalation are active
    • involves accessory muscles during inhalation
    • internal intercostals and abdominal muscles during exhalation
  58. Tidal volume
    is the amount of air moved into or out of the lungs during a single respiratory cycle
  59. Expiratory reserve volume
    • during a normal,quiet respiratory cucle under resting conditions the tidal volume averages 500 mL
    • The amount that can be expelled at such a respiratory cycle is 1000 mL- ERV
  60. Inspiratory reserve volume
    • IRV is the ammount of air that can be taken in over and above the resting tidal volume
    • 3300mL male vrs 1900mL female
  61. vital capacity
    the sum of the IRV and ERV
  62. Residual volume
    • is the ammount that remains in the lungs even after a maximal exhalation
    • typicallt 1200 in male and 1100 in female
  63. Minimal volume
    • chest cavity has been penetrated the ammount of air in the respiatory system is reduced to the minimal volume
    • because surfactant prevents the collapse of aveolar surfaces
  64. Anatomic dead space
    150 mL left over in passageways
  65. Objective:
    Describe how oxygen and carbon dioxide are transported in the blood (pp.565-572)
  66. Gas exchange between blood and aveolar vair across the membrane depends on
    • The partial pressures of the gases involved
    • diffusion of molecules between a gas and a liquid
  67. N2 is the most abundent gas and accounts for what % of the atmospheric gas molecules
  68. % O2 in atomosphere
  69. Atmospheric pressure at sea level is
    760 mmHg
  70. Partial pressure
    • pressure contributed by a single gas
    • and is abbreviated at P
  71. Partial pressures (mmHg) and normal gas concentrations(%)in the air
    Inhaled Air(dry)
    • (N2) 597(78.6%)
    • (O2) 159 (20.9%)
    • (H2O) 3.7(0.5%)
    • (CO2) 0.3 (0.04%)
  72. Partial pressures (mmHg) and normal gas concentrations(%)in the air
    Aveolar Air(saturated)
    • (N2) 573(75.4%)
    • (O2) 100 (13.2%)
    • (H2O) 47(6.2%)
    • (CO2) 40 (5.2%)
  73. Partial pressures (mmHg) and normal gas concentrations(%)in the air
    Exhaled Air(saturated)
    • (N2) 569(74.8%)
    • (O2) 116 (15.3%)
    • (H2O) 47(6.2%)
    • (CO2) 28 (3.7%)
  74. Respiration is divided into
    • Internal 
    • External
  75. Internal respiration
    Diffusion between blood and interstital fluid across the endothelial cells of capillary walls
  76. External respiration
    is the diffusion of gases between the blood and alveolar air across the respiratory membrane.
  77. Deoxygenated blood delieverd by the pulmonary arteries has _____ PO2 and a _____ PCO2 then aveolar air
    lower, higher
  78. Diffusion between the alveolar air and pulmonary capillaries thus
    elevates the PO2 of Blood while lowering its PCO2
  79. Blood departs Aveoli with a PO2 and a PCO2 of
    • 100 mmHg PO2
    • 40 mmHg PCO2
    • roughly
  80. Normal interstital fulid has PO2/PCO2 of
    • 40 mmHg PO2
    • 45 mmHg PCO2
    • roughly
  81. Three ways Hb releases Hb
    • PO2 
    • pH
    • Temperature
  82. Carbon Dioxide in the blood stream
    • dissolve in plasma
    • bind to Hb within red blood cells
    • be converted ti a molecule of carbonic acid H2CO3) All three process are completely reversable
  83. Hb+O2<-->HbO2
  84. When Ph declines  hemoglobin releases
    bound O2
  85. 7 % of CO2 is
    absorbed by peripheral cappillaries and transported as disolved gas molecules
  86. Carbaminohemoglobin
    23% CO2 transported this way
  87. Carbonic acid
    • 70% CO2 transported as bicarbonate ions
    • molecules dissociate immediately into a hydrogen and a bicarbonate ion
  88. Carbonic anhdrasey
    CO2+H2O<------> H2CO3 <-->H+ + HC)-3

    CO2+H2O<---> H+ HCO-3
  89. Chloride shift
    Mass movement of chloride Ions into RBC
  90. Objective:
    Describe the major factors that influence the rate of respiration (pp.573)
  91. Under normal conditions cellular rates of absorption and generation are ______ by the rates of delivery and removal at the capillaries .
  92. Rates on the cellular level are _____ to the oxygen absorption and carbon dioxide exretion at the lungs.
  93. Equilibrium is restored through homeostatic mechanism that involve
    • Changes in blood flow and oxygen delivery under local control
    • Changes in the depth and rate of respiration under the control of the brain's respiratory centers
  94. If peripheral tissue becomes more active
    intersitial PO2 falls and PCO2 rises
  95. The more oxygen delivered the more co2 is
    carried away
  96. Rise in PCO2 levels cause the relaxation of
    smooth muscles in the walls of arterioles in the area, which increases blood flow
  97. PCO2 increases
    bronchioles dilate
  98. PCO2 decline
    bronchiles constrict
  99. Involuntary respiratory centers are located where and what do they regulate?
    • Meulla oblongata and the pons
    • regulate the respiratory muscles and control the frequency and depth of breathing
  100. voluntary control reflects the
    cerebral cortex
  101. Respiratory centers are three pairs of
    nuclei in the reticular formation of the pons and medulla oblongata
  102. Respiratory rhythmicity centers
    set the pace for respiration
  103. Each center can be subdivided into a DRG and a VRG that have
    • Dorsal respiratory group ,insiratory center
    • Ventral respiratory group, expiratory group
  104. DRG functions in
    every respiratory cycle
  105. During quiet breathing, the neurons of the insoratory center
    gradually increase stimulation of the inspiratory muscles, for two seconds and then inspiratory center becumse silent for next three seconds
  106. VRG only functions during
    • forced breathing
    • when it activates the acessory muscles involved in ihalation and exhalation
  107. Objective: Identify the reflexes that regulate inspiration (pp. 574-575, 577)
  108. What receptors modify activites by sensory information to respiratory center
    • mechanoreceptors (baro and stretch)
    • chemoreceptors
  109. Induced changes are called
    respiratory reflexes
  110. Mehanoreceptors respond to
    changes in volume in lungs andchanges in arterial blood pressure
  111. Inflation reflex
    prevents lungs from overexpanding
  112. deflation reflex
    inhibits the expiratory center and stimulates the inspiratory center when lungs are collapsing
  113. Together the reflexes are known as the
    hering breuer reflexes
  114. Chemorecptors sensitive to