Pulmonary Histology S1M3

  1. The patency of the respiratory system is maintained by what elements
    Bone, cartilage, and fibrous tissues
  2. What components make up the respiratory portion of the respiratory system
    • Bronchioles
    • Alveolar ducts and sacs
    • Alveoli
  3. What are the three parts of the nasal cavity
    • Vestibule
    • Respiratory segment
    • Olfactory segment
  4. What cell type is the vestibule lined by
    Stratified squamous epithelium, continuous with the outside skin
  5. What are the stiff hairs in the vestibule called
    Vibrissae, they trap large particulate matter
  6. What is in the dermis of the vestibule that assists in trapping foreign particulate
    Sebaceous and sweat glands which secretions aide in catching particles
  7. What lies just posterior to the nasal cavity
    Three bony shelves called nasal conchae (turbinates)
  8. What is the function of the nasal conchae
    They warm the air, moisten the air, clean the air, and create a turbulence in the air.
  9. What happens to the type of epithelium posterior to the vestibule
    It transitions from stratified squamous to respiratory epithelium
  10. Where does the respiratory epithelium cover
    From just behind the vestibule to the small bronchioles
  11. What is respiratory epithelium composed of
    Ciliated pseudostratified columnar epithelium with goblet cells
  12. Almost all of the nose is covered by the respiratory epithelium except
    Vestibule and chemosensory area
  13. What are the five cell types found in the respiratory epithelium (Pseudostratified ciliated columnar epithelium)
    • Ciliated columnar
    • Mucous goblet cells
    • Brush cells
    • Basal cells
    • Small granule cells
  14. What is unique about the ciliated cells in the respiratory epithelium
    They all beat in unison
  15. What is the job of the goblet cells in the respiratory epithelium
    They secrete mucus which acts as a blanket over the ciliated cells
  16. What act as the anchoring site for ciliary axonemes
    Basal bodies
  17. When there are abundant cilia, what other organelle must be close
    Mitochondria for ATP production
  18. What is kartageners syndrome
    • Immotile cilia due to a lack of dynein
    • Make men sterile and mucus airways don't clear well
  19. What is the job of a brush cell
    They have several microvilli that act as sensory receptors
  20. Microvilli on brush cells can be mistaken for
  21. What is the purpose of basal cells in the respiratory epithelium
    They can differentiate into sustentacular cells and olfactory cells
  22. What is the purpose of the granule (enteroendocrine) cells
    They secrete bombesin and seritonin that control the functioning of other cells in the respiratory epithelium
  23. What can granules be mistaken for
    Basal cells but are differentiated by the many granules inside
  24. What is beleived to be the function of bombesin and seritonin in the lungs and where else can they be found
    Regulate smooth muscle tone, bronchial flow, and airway secretions. They can also be found in the GI tract
  25. What type of epithelium are the olfactory epithelium
    Pseudostratified columnar epithelium (different form respiratory epithelium)
  26. What cells are in the olfactory epithelium
    • Olfactory receptor cells (neurons)
    • Supporting cells (sustentacular)
    • Basal cells
  27. The nasal cavity is usually divided into what three parts
    • Vestibule
    • Respiratory segment
    • Olfactory segment
  28. What are the two conditions that must be met for a compound to have a smell or odor
    • Volatile
    • High enough concentration to interact with olfactory receptors
  29. What compounds have the widest range of odors
  30. What happens to an olfactory receptor when an odor binds to it
    It undergoes a structural change then binds and activates the olfactory-type G protein on the inside of the olfactory receptor neuron
  31. What is the structure of an olfactory sensory neuron
    It has modified immotile cilia on their free surface containing odorant receptor proteins and a single axon extending to the brain
  32. How long does one olfactory neuron live
    Around a month
  33. What makes new olfactory neurons
    Basal cells
  34. What is the significant of Olfactory cells
    • Bipolar neurons
    • Spans the breadth of the whole epithelium
    • Nucleus is centrally located
    • 2 cytoplasmic processes (dendritic and proximal)
    • Cilia on its surface
    • Only neurons in the body exposed directly to the external environment
  35. What bone must the axons of the olfactory neurons penetrate to reach the olfactory bulb
    Cribriform bone
  36. Sustentacular cells (supporting cells) have what characteristics
    • Ovoid cells
    • Nucleus on apical end
    • Narrow base broad apex
    • Microvilli
    • Yellow brown pigment
  37. What is the job of the supporting (sustenacular) cells
    They provide physical and metabolic support to olfactory cells
  38. What are bowmans glands and their job
    Olfactory glands. Serous secreting glands which act as a solvent for odorous substances to be cleared for new ones to be brought in
  39. How are the olfactory neurons different then all other neurons
    • They are subjected to the outside world
    • They attach many molecules instead of just one
  40. Each olfactory neuron expresses how many receptors
    Just one
  41. Olfactory receptors are coupled to what and act on what channels
    G protein acting on ion channels
  42. Olfactory cells synapse on what cells
    Mitral cells in the olfactory bulb
  43. Naegleria fowleri
    The brain eating amoeba that enters the nasal cavity and into the olfactory bulb
  44. What is the difference in epithelial types from the nasopharynx and the oral and laryngeal pharynx
    • Naso is lined by respiratory epithelium
    • Oral and Laryngeal are lined by stratified squamous epithelium
  45. What is the job of the larynx
    • Voice box
    • Control of air pathway separating it from food
  46. True vocal chords consist of
    • Stratified squamous epithelium
    • Vocal ligament
    • Vocal muscle
  47. The false vocal cords are made of
    • Respiratory epithelium
    • Lamina propria (w/many exocrine glands)
  48. Metaplasia
    The reversible replacement of one cell type to another (not the same as dysplasia)
  49. Dysplasia
    Abnormal development of cells, usually indicates beginning of neoplasia
  50. The trachea is surrounded by C rings and attached at their ends by
    • Smooth muscle
    • Dense fibroelastic ligament (attaches other rings)
  51. The open cartilage C rings in the trachea face what structure
  52. In what layer of the trachea are the seromucous glands located
  53. What are the three layers of the trachea
    • Mucosa
    • Submucosa
    • Adventitia
  54. What makes up the mucosa of the trachea
    • Respiratory Epithelium
    • Thick basal lamina
    • Lamina propria
  55. What is the lamina propria of the trachea rich in
    Elastic fibers and lymphocytes
  56. As the airways get smaller what gets more prevalent and what gets less prevalent
    • Smooth muscle is more prevalent
    • Cartilage, Glands, goblet cells, and height of epithelial cells gets diminished
  57. Lamina propria is another name for
    Basement membrane
  58. What happens to the cartilaginous rings of the bronchi when they enter the lungs
    They are no longer C shaped rings but become a cartilaginous plate of irregular shape
  59. When do the bronchi become bronchioles
    When the cartilaginous plates disappear
  60. What are the effects of the parasympathetic and sympathetic innervation on the bronchioles
    • Para - Contraction
    • Symp - Relaxation
  61. Bronchioles contain no
    Cartilage or seromucous glands
  62. Clara cells
    • Dome shape cells with short microvilli found only in the bronchioles
    • They are identified by their bulging apical cytoplasm
  63. What is the function of the Clara cells
    • To protect the bronchiole epithelium
    • Detoxify harmful substances
    • Divide and differentiate to form ciliated and non ciliated epithelial cells
  64. What substances in the Clara cells are secreted that protect the bronchioles
    • Clara cell secretory protein (CCSP) a product of lung
    • surfactant
    • Glycosaminoglycans (GAG's) that prevent luminal adhesion
    • Both decrease inflammatory response
  65. How do the Clara cells detoxify harmful substances
    They contain Cytochrome P450 that metabolizes airborne toxins often contained in the ER
  66. Clara cells do not form ciliated cells in the
    Respiratory epithelium
  67. Gas exchange in the lungs happens where
    In the Alveoli only
  68. The wall of the aveolar ducts which seperate the aveoli are made up of
    Elastic, collagen, and smooth muscle fibers
  69. What is the only portion of the respiratory tree that doesn't contain smooth muscle
    Alveolar sacs (but it is in the ducts)
  70. What type of cells are found on the alveoli
    • Alveolar cells (pneumocytes) Type I and II
    • Alveolar macrophages
  71. What is the purpose of the two types of alveolar cells
    • Type I gas exchange
    • Type II secrete surfactant
  72. What kind of cells are pneumocyte type I
    • Simple squamous epithelial cells
    • Joined by tight junctions
  73. What are type I pneumocytes made by
    • Type II
    • They don't divide on their own
  74. What are type II pneumocytes made up of
    Cuboidal cells
  75. What is the purpose of surfactant
    Reduces the surface tension at the blood air barrier and prevents collapse of alveoli
  76. Surfactant is rich in
    Phospholipids and phosphotidylcholine
  77. What happens when there is not enough surfactant in the body
    It leads to cyanosis and respiratory distress syndrome (RDS) happens most frequently in children
  78. What are newborns treated with that are low in surfactant
    Synthetic surfactant and glucocorticoid therapy which can cross the placenta
  79. How does glucocorticoid therapy treat low surfactant
    It stimulates type II pneumocytes to secrete surfactant
  80. What are the components of the blood air barrier
    • Alveolar epithelial cells
    • Basal lamina of alveolar epithelium
    • Basal lamina of capillary endothelium
    • Endothelial cell of capillary network
  81. Alveolar macrophages are also called
    Dust cells
  82. Where do the alveolar macrophages do their work
    • In the air space and the interalveolar septum
    • Uniquely they move between air and liquid
  83. How are alveolar macrophages often removed
    They are moved up the bronchioles by the ciliary tract and swallowed getting destroyed in the stomach
  84. Alveoli have pores that have what function and name
    • The pores of Kohn
    • Found in the interalveolar septum
    • They equalize the pressure in the alveoli and allow macrophages in
  85. What happens to the lungs in emphysema
    Destruction of the interalveolar wall making fewer but larger alveoli
  86. Many people with COPD also have
    Chronic bronchitis and emphysema
Card Set
Pulmonary Histology S1M3