Respiratory Anatomy Flashcards
Histologically, what makes up the bronchi?
Cartilage, goblet cells and glands extend to the end of the bronchi
Histologically, how far do the Pseudostratified Ciliated Columnar Cells extend?
Pseudostratified ciliated columnar cells (clear mucus from lungs) extend from the bronchi to BEGINNING of terminal bronchioles, then they transition to cuboidal cells
Histologically, how far do the airway smooth muscle cells extend?
They extend from the bronchi to the END of terminal bronchioles (sparse beyond this point)
What is the function of the conducting zone?
Warms, humidifies and filters air but does not participate in gas exchange, considered “anatomic dead space”
What structures make up the conducting zone (large airways + small airways)?
Large airways: nose, pharynx, larynx, trachea and bronchi
Small airways: bronchioles that further divide to terminal bronchioles
What is the function of the respiratory zone?
Participates in gas exchange
What structures make up the respiratory zone?
Respiratory bronchioles, alveolar ducts and alveoli
everything distal to the terminal bronchioles
Histologically, which cells make up the respiratory bronchioles?
Cuboidal cells
Histologically, which cells make up the alveoli?
Simple Squamous Cells
alveolar macrophages clear debris and participate in immune response
When do cilia terminate?
In respiratory bronchioles
Which type of pneumocyte is more abundant in the alveoli?
Type I (make up 97% of alveolar surfaces)
Which type of pneumocyte secretes surfactant?
Type II
Which type of pneumocyte proliferates during lung damage?
Type II
Type II cells serve as precursors to Type I cells and other Type II cells
Which type of pneumocyte is squamous?
Type I, which are more abundant and line the alveoli, are squamous; thin for optimal gas diffusion
Which type of pneumocyte is cuboidal and clustered?
Type II
What is the function of surfactant?
Decreases alveolar surface tension and prevents alveolar collapse (atelectasis)
What type of cells are Club (Clara) Cells and where are they found?
Nonciliated; low-columnar/cuboidal with secretory granules
Found in the bronchioles, NOT in the alveoli
What is the function of Club (Clara) Cells?
Secrete a component of surfactant
Degrade toxins via the cytochrome P450 pathway
Act as reserve cells
What is the equation for collapsing pressure?
Collapsing Pressure (P) = 2 (surface tension) / Radius
At what stage of breathing do alveoli have the greatest tendency to collapse?
Expiration b/c the radius decreases as air is expired from the lungs (law of Laplace)
What is the major component of pulmonary surfactant?
It’s a complex mix of lecithins, the most important of which is: dipalmitoylphosphatidylcholine
What does surfactant synthesis begin during gestation and when are mature levels achieved?
Begins around week 26
Mature levels are achieved at week 35
What lecithin-to-sphingomyelin ratio in the amniotic fluid indicates fetal lung maturity?
> 2
How many lobes are in the right lung?
3 lobes (superior, middle and inferior)
