Respiratory System 1

  1. Why Do We Breathe?
    • ATP synthesis requires oxygen and produces carbon dioxide
    • Respiratory and circulatory systems work together to bring oxygen to tissues and remove carbon dioxide
    • Sometimes called cardiopulmonary system
    • Disorders of lungs directly affect the heart and vice versa
    • Respiratory and urinary systems work together to regulate acid/base balance
  2. Respiratory System Functions
    • Provide extensive surface for O2 and CO2 exchange
    • Allow production of sounds for speaking
    • Facilitates smell
    • Regulates pH of bodily fluids
    • Regulates blood pressure (angiotensin II)
    • Pressure gradients promote venous blood flow
    • Expel abdominal contents during urination, defecation, and childbirth
  3. Conducting Division
    • Passages that serve for air flow, not gas exchange
    • Nose, pharynx, larynx, trachea, bronchioles
  4. Respiratory division
    • Gas exchange regions
    • Alveoli of lungs
  5. Upper respiratory Tract
    • In head and neck
    • Nose through larynx
  6. Lower Respiratory Tract
    • Organs of thorax
    • Trachea through lungs
  7. Respiratory Epithelium
    • Goblet cells secrete mucus
    • Cilia project mucus towards pharynx, where it's swallowed into digestive tract
    • Called mucociliary elevator below pharynx, where cilia beat mucus in an upward direction
    • Best protection against invading pathogens, allergens, and dust
  8. Cystic Fibrosis
    • Gene responsible for regulating components of mucus is mutated, so mucus is unusually thick
    • Mucus can't be carried by cilia, so pathogens are trapped and infection is common
  9. Nose
    • Warms, cleanses, and humidifies inhaled air
    • Extends from nostrils to posterior nasal apertures
    • Facial part shaped by nasal bone and cartilage
  10. Nasal Fossae
    Right and left halves of nasal cavity; divided by septum
  11. Septums of the Nose
    Vomer, perpendicular plate, septal cartilage
  12. Vestibule
    • Opening of nasal cavity
    • Vibrissae in vestibule block insects and debris
  13. Nasal Conchae
    • Folds of tissue with meatus beneath each one
    • Air must contact mucous membrane before continuing on
    • Ensures trapping most dust
  14. Pharynx
    • Muscular funnel between posterior nasal apertures and larynx
    • Shared by respiratory and digestive systems
  15. Nasopharynx
    • Posterior to nasal apertures
    • Receives eustachian tubes from middle ears
    • Houses pharyngeal tonsil
    • Large particles can't make sharp turn and get caught in mucosa near tonsil
    • Passes only air
  16. Oropharynx
    • Space between soft palate and epiglottis
    • Contains palatine tonsils
    • Pass air, food, drink from oral cavity and nasopharynx
  17. Laryngopharynx
    • From epiglottis to esophagus
    • Lies posterior to larynx
    • Passes air, food, drink
  18. Functions of the Larynx
    • Keeps food and drink out of the airway
    • Epiglottis guards superior opening of larynx
    • Stands vertically at rest
    • When swallowing, extrinsic muscles pull larynx upward and tongue pushes epiglottis downward to meet it and close off larynx (food goes to esophagus)
    • Vestibular folds: close the larynx during swallowing
    • Vocal cords/glottis: Involved in sound production (phonation)
  19. Vocal Cords
    • Intrinsic muscles of larynx move arytenoid and corniculate cartilage
    • Adducted cords create higher pitch
    • Abducted cords create lower pitch
    • Length and thickness of cords determine range of pitches able to be produced
  20. Trachea
    • Supported by C-shaped rings of hyaline cartilage
    • Maintains structure
  21. Intubation and Tracheostomy
    Methods of bypassing upper respiratory system
  22. Right Lung
    • Shorter, wider
    • 3 Lobes: superior, middle, and inferior
    • Horizontal and oblique fissure
  23. Left Lung
    • Taller, narrower
    • 2 Lobes: superior and inferior
    • Oblique fissure
  24. Main (primary) Bronchi
    • Each main (primary) bronchi: branches into 65,000 terminal bronchioles
    • Supported by c-shaped hyaline cartilage
  25. Lobar (secondary) Bronchi
    • Supported by cartilage plates
    • One lobar bronchus to each lobe
  26. Segmental (tertiary) Bronchi
    • Supported by cartilage plates
    • 10 in right lung, 8 in left
    • Each ventilates a bronchopulmonary segment
  27. Bronchial Tree
    • All divisions have elastic connective tissue which allows for expansion during inhalation and then recoils to expel air during exhalation
    • Mucosa layer has smooth muscle to allow for constriction/dilation of airway
    • Sympathetic innervation: causes bronchodilation
    • Parasympathetic innervation: causes bronchoconstriction
    • Pulmonary artery branches follow bronchial tree to alveoli
    • Bronchial artery arises from thoracic aorta to provide bronchial tree with blood
  28. Bronchioles
    • No cartilage
    • Pulmonary lobule: part of lung ventilated by one bronchiole
    • Divides into 50-80 terminal bronchioles
    • Each terminal bronchiole divides into two or more respiratory bronchioles
    • Respiratory bronchioles have alveoli budding off of them
  29. Alveoli
    • 150 million in each lung
    • Three types of cells:
    • Squamous (type 1) alveolar cells: thin, broad; allow for rapid gas diffusion between alveoli and bloodstream
    • Great (type II) alveolar cells: repair epithelium, secrete pulmonary surfactant (coats alveoli to prevent them from collapsing during exhalation)
    • Alveolar macrophages (dust cells): phagocytose dust particles, then ride up mucociliary escalator to be swallowed
  30. Pleurae
    • Fluid-filled cavity surrounding lungs
    • Reduces friction when lungs expand
    • Create pressure gradient to assist with lung inflation
    • Prevent spread of infection from one organ to another
  31. Pulmonary Ventilation (breathing)
    • Consists of repetitive respiratory cycles: one complete inspiration, one complete expiration
    • Quiet respiration: quiet, effortless
    • Forced respiration: deep, rapid (exercise)
    • Depends on pressure difference between lungs and external environment
    • Respiratory muscles change lung volume, which changes pressure
Card Set
Respiratory System 1
Respiratory System