5 Structure and Function of the Airways Flashcards
Q: Which interface is designed for gas exchange? What else does this interface need to be able to do? why?
A: Interface between external air and alveolar region for gas exchange
other substances breathed in as well -> must be equipped to defend itself
Q: What the 2 main functions of the airways? What facilitates these functions? (3) Describe. (3,2,2)
A: conduit to conduct O2 to alveoli; conduct CO2 out of lung = gas exchange
facilitated by
- mechanical stability : cartilage -> keeps open
- cartilage is C-shaped with opening at back of trachea for oesophagus (C shaped so doesn’t make it difficult for food to go down) -> allows for bronchoconstriction
- cartilage is slightly offset compared to each other -> ++ tensile strength)= less easily compressed - control of calibre (smooth muscle)
- protection and “cleansing”
Q: Name 7 cell categories.
A: Lining cells
Contractile cells
Secretory cells
Connective tissue
neuroendocrine
Vascular cells
Immune cells
Q: Name the 4 lining cells.
A: Ciliated, intermediate, brush, basal
Q: What are contractile cells called? (2)
A: Smooth muscle (airway, vasculature)
Q: Name 3 secretory cells. Include 2 locations.
A: Goblet (resp epithelium and reproductive tracts- are cells in their own right), mucous (specialised epithelium cells), serous (glands)
Q: Name 2 connective tissue cells. 3 examples?
A: Fibroblast, interstitial cell (elastin, collagen, cartilage)
Q: Name 4 neuroendocrine cells.
A: Nerves, ganglia, neuroendocrine cells, neuroepithelial bodies
Q: Name 3 (+1) vascular cells.
A: Endothelial, pericyte, plasma cell (+ smooth muscle)
Q: Name 6 immune cells.
A: Mast cell, dendritic cell, lymphocyte, eosinophil, macrophage, neutrophil
Q: What mixture lines airway epithelium? What does it contain? (9) Produced by?
A: Mucus- mucins, water, electrolytes, plasma, mediators, inorganic salts, antiseptic enzymes (such as lysozymes), immunoglobulins, glycoproteins such as lactoferrin and mucins
goblet cells
Q: In airway epithelium, what moves mucus along? process name? What does airway epithelium act as? What are the 2 main cells of airway epithelium?
A: movement of mucous by cilia -> mucociliary clearance
physical barrier
- ciliated
- goblet
Q: What is produced by airway epithelium? (2) Name 6 examples, including what produces it for some.
A: production of regulatory and inflammatory mediators
- NO by NOS
- CO by hemeoxygenase
- Arachidonic acid metabolites e.g. prostaglandin
- Chemokines e.g. ILs
- Cytokines e.g. GM-CSF
- Proteases
Q: What do ciliated cells contain? What are cilia? structure? role? What lies on top of cilia?
A: ++ mitochondria
cilia: have apical “hooks” (engage with mucus); 9+2
metacronal beating to move mucous to back of throat with particles etc.
mucous layer on top of cilia
Q: What do goblet cells contain lots of? What happens to this structure? (2) What is the structure of this structure outside of the goblet cell?
A: mucin granules in highly condensed form
hydrates when fuses with cell membrane -> expelled
when they are released- increase in size by 600 (many 100) fold (take in water)
Q: What is also part of airway epithelium? where? (3) What do these structures contain and what do they do? (3)
A: Airway submucosal glands
- between 2 epithelial (or goblet) cells
- extend down past basal lamina
- > basal part embedded in smooth muscle layer
- mucous cells secrete mucous
- serous cells secrete antibacterials (e.g. lysozyme)/
- glands also secrete water and salts (e.g. Na+ and Cl-)
