Flashcards in Pulmonary Deck (34):
Anatomical Dead Space (and the generations which make it up)
Volume of anatomical dead space
transitioning from conducting to respiratory
Volume of lung which participates in gas exchange
What type of cells produce surfactant?
Alveolar type II
Important Connections for Interdependence of bronchioles
Channels of Martin (interbronchial)
Channel of Lambert (bronchiole-alveoli)
Pores of Kohn (interalveolar --> collateral ventilation)
Change in volume during normal breathing
Inspiratory Reserve Volume
Volume which can be inhaled on top of Vt
Expiratory Reserve Volume
Volume which can be exhaled beyond Vt
Volume that remains in lung even after forced expiration
Total you can inspire
IC= IRV +Vt= 3500mL
Functional Residual Capacity
Volume of air in lungs when all respiratory muscles are relaxed.
FRC=ERV + RV =2400mL
Max air which can be moved from deep expiration to deep inspiration.
VC= IRV + Vt +ERV= 4700mL
Tung Lung Capacity
Total volume of air held by the lungs
TLC= IRV + Vt + ERV + RV = 5900mL
What method can measure FRC?
Amount of air you can push out in 1 sec/ total amount of air you can push out
Volume of respiratory region (non-dead space)
Methods which can measure RV
3 flow types and the generations they're associated with.
Turbulent: Generations 0-9
Laminar: Generations 10-16
Diffusive: Generations 17-23 (occurs continuously and independent of respiratory cycle)
Elastic work is proportional to...
Non-elastic work is proportional to...
Elastic --> Tidal Volume
Non-elastic (restriction-based) --> Frequency of Breathing
4 Causes for Hypoxemia
(1) Hypoventilation (no change in AaDO2)
(2) Diffusion Limitation (thickness, reduced area, etc.)
(3) Shunt (no change from increased O2)
Hypoxia vs Hypoxemia
•Hypoxia- deprivation of the body or specific organs due to mismatch in oxygen supply and tissue demands
•Hypoxemia- when oxygen concentration in arterial blood is too low
◦PaO2 less than 80 mmHg
◦Signs visible less than 60 mmHg
- Initial Hypertension
- Bradycardia (vagally induced)
- Splenic contraction
Hypoxic Loss of Conciousness
Calculating Physiological Dead Space
Vd/Vt = (PaCO2- PeCO2)/PaCO2
(what could be expired - what is expired)/what could expired
Normal ratio: .2-.35
Vt: in place to normalize physiological dead space for a given tidal volume
The amount of gas transferred is proportional to the area (A), and difference in partial pressure
Describes the factors which aid diffusion; tells us CO2 diffuses 22x better than O2
When a part of the lung has low ALVEOLAR PO2, blood is shifted from hypoxic areas to well-perfused areas (so as to not waste blood where it won't be ventilated)
Causes of AaDO2
- Anatomic shunt
- Bronchial/Pulmonary veins
The concentration of a solute gas in a solution is directly proportional to partial pressure of that gas above the solution.
C= kH (P)= concentration is solution= dissolving constant (pressure)
Function of CO
In the presence of small amounts of CO, affinity for O2 is greatly enhanced and unloading is prevented (hence suffocation).
When intracellular [H+] and [HCO3-] increase in erythrocytes, HCO3- diffuses out and Cl- in, to maintain electrical neutrality
The presence of O2 decreases the affinity of hemoglobin for CO2 and assists in the unloading of CO2 from the blood to the alveolar spaces