21: Embryo, ARDS, OLD

Question 1

function of type I vs type II pneumocytes

Answer 1

type I: facilitate gas exchange

type II: produce surfactant, replace type Is (like SCs)

Question 2

alveolar pores of Kohn

Answer 2

allow air/bacteria/fluid to travel between alveoli

Question 3

MC cause of COPD and chronic bronchitis

Answer 3

smoking

Question 4

why does Hb go up in chronic bronchitis

Answer 4

smoking -> exposure to CO -> binds Hb -> shifts O2 dissociation curve to the left -> reduces O2 carrying capacity -> compensates by making more Hb

Question 5

why is smoking-related emphysema centrilobular?

Answer 5

causes constriction of the terminal bronchiole -> dilation starts at the respiratory bronchiole and moves distally

Question 6

four components of asthma

Answer 6

1. recurrent airway obstruction
2. airway hyper-responsiveness
3. airway inflammation
4. variable remodeling

Question 7

four physiologic things that happen in asthma + the mediators that cause them

Answer 7

1. bronchoconstriction: leukotrienes C4D4E4, histamine, prostaglandin D2, Ach
2. Mucus secretion: Leukotrienes C4D4E4
3. increased vascular permeability: leukotrienes C4D4E4
4. Recruitment of inflammatory cells: ILs

Question 8

Four diagnostic criteria for ARDS

Answer 8

1. Acute onset sx
2. PaO2/FiO2 <200
3. Bilateral infiltrates on CXR
4. Non-cardiac in nature

Question 9

What PaO2/FiO2 is required to dx ALI

Answer 9

<300