Updated: 12/23/2020

Microanatomy of the Lung

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
7 7
0
0
0%
0%
Evidence
4 4
0
0
Topic
Key Images
https://upload.medbullets.com/topic/117002/images/alveoli.jpg
Overview
  • Airway lining
    • pseudostratified ciliated columnar cells extend to the bronchioles 
      • mucus secretions are swept out of the lungs toward the mouth by ciliated cells
      • smoking causes these cells to undergo metaplasia 
        • replaced by stratified squamous
    • simple ciliated columnar epithelium extends to the terminal bronchioles
    • ciliated cuboidal cells extend to the respiratory bronchioles
    • alveolar sac are composed of pneumocytes
      • macrophages clear debris in alveoli
    • goblet cells extend to the larger bronchioles but stop before the terminal bronchioles
  • Type I pneumocytes
    • 97% of alveolar surfaces
    • line the alveoli
    • squamous
    • thin for optimal gas diffusion
    • form blood-gas barrier with pulmonary capillary endothelial cells 
  • Type II pneumocytes
    • 3% of alveolar surfaces
    • secrete pulmonary surfactant within lamellar bodies 
      • dipalmitoyl phosphatidylcholine
      • lowers the alveolar surface tension
    • cuboidal and clustered 
    • serve as precursors to type I cells and other type II cells
    • proliferate during lung damage
  • Club (Clara) cells
    • nonciliated
    • columnar with secretory granules
    • secrete component of surfactant
    • degrade toxins
    • act as reserve cells
  • A lecithin-to-sphingomyelin ratio of > 2.0 in amniotic fluid is indicative of fetal lung maturity
Topic Rating

Please rate topic.

Average 5.0 of 3 Ratings

 

Questions (7)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M1.PL.15.71) A 67-year-old male with a 40 pack-year history of smoking visits his physician with a complaint of coughing up blood and recent unintentional weight loss. The physician is concerned about lung cancer given the patient's smoking history. A full workup demonstrates a suspicious lung mass and a lung biopsy is subsequently performed. Which of the following figures correctly demonstrates the type of epithelium which is normally found in the tracheobronchial tree? Tested Concept

QID: 106495
FIGURES:
1

Figure A

5%

(5/96)

2

Figure B

5%

(5/96)

3

Figure C

2%

(2/96)

4

Figure D

6%

(6/96)

5

Figure E

78%

(75/96)

M 1 D

Select Answer to see Preferred Response

(M1.PL.14.70) A 67-year-old man is hospitalized after several days of fever and increasing shortness of breath. Respiratory viral panel returns positive for influenza A and the patient is started on a standard five day course of oseltamivir. Despite therapy, his shortness of breath continues to worsen and his oxygen saturation decreases to the point where ICU transfer and intubation are required. Chest radiograph shows bilateral infiltrates. Clinical criteria are consistent with development of Acute Respiratory Distress Syndrome (ARDS). After several weeks of supportive therapy, the patient improves with lung function returning to near normal. Which of the following processes is involved in the regeneration of alveolar lining after damage to alveoli occurs? Tested Concept

QID: 106485
1

Squamous cell proliferation

3%

(2/60)

2

Sweeping of debris out of the alveoli by ciliated cells

0%

(0/60)

3

Excess mucus production by goblet cells

2%

(1/60)

4

Proliferation of surfactant-secreting cells

83%

(50/60)

5

Proliferation of club cells

8%

(5/60)

M 1 E

Select Answer to see Preferred Response

Evidence (5)
Topic COMMENTS (15)
Private Note