Respiratory System

  1. Major divisions of the respiratory system
    • Conducting portion
    • - nasal cavity
    • - nasopharynx
    • - larynx
    • - trachea
    • - bronchi
    • - terminal bronchioles
    • Respiratory portion
    • - respiratory bronchioles
    • - alveolar ducts
    • - alveoli
  2. Nasal cavities
    Paired chambers separated by bony/cartilage septum

    • Each chamber is divided into:
    • 1. vestibule
    • 2. respiratory segment
    • 3. olfactory segment
  3. Vestibule of nasal cavity
    • Site of comm w/ ext. environment
    • Stratified squamous keratinized (w/ hairs)
  4. Where does the transition of epithelium occur in the nasal cavity?
    End of vestibule

    • a) Stratified squamous keratinized (w/ hairs)
    • b) Pseudostratified columnar ciliated (w/ goblet cells)
  5. What is respiratory epithelium?
    • Pseudostratified columnar ciliated epithelium
    • (w/ goblet cells)

    Basal cells give rise to respiratory epithelium
  6. Respiratory segment of nasal cavity
    • Lined w/ respiratory epithelium
    • - underlying LP attached to periosteum
    • - lateral wall charachterized by chonchae (a.k.a. turbinates)
  7. Function of conchae / turbinates
    • 1. increase surface area
    • 2. cause turbulance
    • 3. warm / moisture air
    • 4. trap particulate in mucus
  8. Lamina propria of the nasal cavity
    • Very vascular (warms air)
    • Contains mucus glands w/ serous demilunes
    • - demilune cells secrete lysozyme (antibacterial)
  9. Olfactory segment of nasal cavity
    • Lined by olfactory epithelium (pseudostrat. columnar)
    • Has 4 cell types:
    • 1) Olfactory cells
    • 2) Sustentacular cells
    • 3) Basal cells
    • 4) Brush cells
  10. Olfactory cells (olfactory segment)
    • Special visceral sensory cells (bipolar neurons / can regenerate)
    • - Olfactory vesicle (apical surface) w/ non-motile cilia (receptors)
    • - Axon arise from basal part of cell
    • - Axons form olfactory n. (CN I)
  11. Sustentacular cells
    • Mechanical / metabolic support for olfactory sensory cells
    • (similar role to glial cells)
  12. Basal cells
    • Mitotic cells
    • - renew sensory / sustentacular cells in olfactory epithelium
  13. Brush cells
    • General sensory cells innervated by trigeminal n. (CN V)
    • Signal touch from olfactory epithelium
    • (also found in respiratory epithelium)
  14. What are bowman's glands?
    Glands w/in olfactory epithelium (wash away olfactory molecules)
  15. Nasopharynx
    • Posterior to nasal cavity (joins w/ oropharynx)
    • - lined w/ respiratory epithelium
    • - posterior wall contains pharyngeal tonsil (adenoids)
  16. Structure / Function of epiglottis
    • - core of elastic cartilage
    • - lingual surface (strat. squam.)
    • - laryngeal surface (pseudostrat. col.)
    • - LP contains mixed mucous / serous glands
  17. Larynx
    • Connects pharynx to trachea
    • Characterized by laryngeal cartilages
    • - maintain patancy of larynx
    • - major role in vocalization
  18. False Vocal Folds
    (ventricular folds)
    • Upper pair of folds in larynx
    • Covered w/ pseudostrat. columnar
    • Lots of serous glands w/in LP
  19. True Vocal Folds
    (vocal cords)
    • Lower pair of folds in larynx
    • - Covered w/ strat. squamous
    • - Parallel bundles of elastic fibers form vocal ligaments
    • - Vocalis mm. parallel to ligaments
  20. Vocalis muscles
    • Skeletal muscles
    • Lie parallel to vocal ligaments
    • Innervation: vagus n. (CN X)
  21. Tracheal mucosa
    • Pseudostrat. ciliated columnar w/ elastic-rich LP
    • cilia beat in unison upward (move mucus to oropharynx)

    • Epithelium rests on very thick BM (dense packed collagen)
    • LP = loose CT (immune cells, diffuse / nodular lymphatics)
  22. Cell types within tracheal mucosa
    • Ciliated cells
    • Goblet cells
    • Brush cells (gen. sensory)
    • Small granule cells (similar to enteroendocrine)
    • Basal cells (repopulate epithelium)
  23. Cartilaginous layer of trachea
    • Hyaline cartilage (16-20, c-shaped)
    • Posteriorly C-shaped cartilage attached by trachealis m. (smooth m.)
  24. Bronchial cartilage
    • Similar to trachea except rings (not c shaped)
    • As bronchi enter lungs, rings replaced by plates
  25. Primary bronchi: intrapulmonary or extrapulmonary
    • Extrapulmonary
    • (outside the lungs)
  26. Layers of intrapulmonary bronchus
    • Starting from the lumen
    • Respiratory epithelium (some goblet cells)
    • Smooth muscle
    • Cartilage plates
  27. Bronchiole components
    • Larger bronchioles = respiratory epithelium
    • Distally -> ciliated columnar -> simple cuboidal
    • Goblet cells found in only largest bronchioles
    • Cartilage replaced w/ smooth muscle (w/ some BV)
  28. Where are clara cells first found? What do they do?
    • First found in the bronchioles
    • Secrete CC16
  29. What is the function of CC16
    • Prevent adjacent bronchiole wall adhesion during expiration
    • (secreted by clara cells)
  30. Smallest conduction part of respiratory tract? What type of epithelium?
    • Terminal bronchioles
    • Simple cuboidal epithelium w/ clara cells
  31. Respiratory bronchiole epithelium
    • Simple cuboidal epithelium
    • Proximal: Ciliated & Clara cells
    • Distally: Clara cells predomninate
  32. Where is the first site of gas exchange?
    Respiratory bronchioles
  33. Alveoli
    • Outpouchings of the lumen of respiratory bronchioles
    • (main site of gas exchange)
  34. Alveolar epithelium
    • Type I pneumocyte:
    • Squamous cells (95% of alveolar lining)
    • Attached to surrounding cells via tight junctions

    • Type II pneumocyte:
    • Secretory cells (surfactant)
Author
mnm2186
ID
33793
Card Set
Respiratory System
Description
Exam 3
Updated