Lungs 4 Flashcards
Compare lung volumes standing vs supine
Supine - inc IRV and dec ERV; inc IC and dec FRC
What is the FRC when standing vs supine?
Supine - 2L
Standing - 3L
What can advanced spirometry measure that basic can’t?
RV, FRC, TLC
What is the gas used to measure RV in advanced spirometry? Why?
Helium - cheap, inert, negligible amount in the atmosphere
Why aren’t other noble gases used for advanced spirometry?
Neon, argon, and xenon - expensive
Radon - reactive in ground (2nd cause of lung cancer)
_______ is the difference in compliance between inspiration and expiration
Hysteresis
When replacing air with saline in the lungs, how does compliance change?
higher compliance, lower hysteresis d/t dec surface tension
How does obstructive lung disease impact pulmonary compliance?
Inc lung volume, inc compliance, dec PTP, dec tissue recoil - hard to exhale
How does restrictive lung disease impact pulmonary compliance?
Dec lung volume, dec compliance, inc PTP, inc tissue recoil - hard to inhale
What are the vital capacities of a normal, obstructive, and restrictive lung?
Normal - 4.5 L
Obstructive - 6 L
Restrictive - 3 L
Emphysema is an example of ______ lung disease, while fibrosis is an example of _______ lung disease
Obstructive, restrictive
What are the 2 components of elastic recoil pressure? Which contributes more?
1/3 elastic tissue
2/3 surface tension
What is the relationship between lung volume and airway resistance?
Inc lung volume = dec airway resistance (inc diameter)
Alveoli open with ________, while large airways open with ________
inc volume
dec/neg pleural pressure
Surfactant ______ surface tension, ________ compliance
breaks, increasing
Surfactant is made up of __% lipids and __% proteins
90% lipids, 10% proteins
Surfactant lipids are ________, meaning they attract and repel water
amphipathic
What are the 2 main surfactant lipids called?
Dipalmitoylphosphatidylcholine
Unsaturated phosphatidylcholine
- both 31% each
What are the 9 lipids that make up surfactant?
- Dipalmitoylphosphatidylcholine
- Unsaturated phosphatidylcholine
- Phosphatidylglycerol
- Phosphatidylinositol
- Phosphatidylserine
- Phosphatidylethanolamine
- Sphingomyelin
- Neutral lipids
- Other lipids
What are the roles of surfactant lipids?
Lower surface tension and change proliferation and cytotoxicity of lymphocytes
What are the roles of surfactant proteins?
- Enhance chemotaxis and phagocytosis
- Aggregation and opsonization of micro-organisms
- Inhibit the growth of pathogens
Which surfactant proteins are hydrophilic? Hydrophobic?
Hydrophilic - SP-A and SP-D
Hydrophobic - SP-B and SP-C
______ cells are mucous-secreting cells in the upper airway
Goblet
______ cells are surfactant-secreting cells in the lower airway
Clara/club
Differentiate between type I and type II alveolar cells
Type I - flat/long, gas exchange
Type II - cube-shaped, secrete surfactant via exocytosis
Are there more type I or type II alveolar cells? Which takes up more gas exchange surface area?
2x more type II than type I
Type II take up 5-10% of SA
Type I take up 90-95% of SA
How is surfactant stored in alveoli? How does it work?
Tubular myelin - storage net for surfactant; falls off during inspiration/negative pressure and floats to the air/water interface to break up water molecules
PPV causes surfactant to _____
decrease
_________ scavenge old surfactant
Alveolar macrophages
_____ cells secrete inflammatory mediators
Mast
How many alveoli are there?
500 million, decrease with age, but can regrow slowly
How many capillaries are estimated per alveolus?
1,000
How large is the surface area for gas exchange?
70m^2 - size of a tennis court
Mast cells primarily secrete _______
histamine
