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Flashcards in Pulmonary Deck (34):
1

Anatomical Dead Space (and the generations which make it up)

Conducting airways.

Generations 1-16

2

Vd

Volume of anatomical dead space

150mL

3

Transition zone

transitioning from conducting to respiratory

generations 17-19

4

Volume of lung which participates in gas exchange

2500mL

5

What type of cells produce surfactant?

Alveolar type II

6

Important Connections for Interdependence of bronchioles

Channels of Martin (interbronchial)
Channel of Lambert (bronchiole-alveoli)
Pores of Kohn (interalveolar --> collateral ventilation)

7

Vt

Tidal Volume

Change in volume during normal breathing

500mL

8

IRV

Inspiratory Reserve Volume

Volume which can be inhaled on top of Vt

3000mL

9

ERV

Expiratory Reserve Volume

Volume which can be exhaled beyond Vt

1200mL

10

RV

Residual Volume

Volume that remains in lung even after forced expiration

1200mL

11

IC

Inspiratory Capacity

Total you can inspire

IC= IRV +Vt= 3500mL

12

FRC

Functional Residual Capacity

Volume of air in lungs when all respiratory muscles are relaxed.

FRC=ERV + RV =2400mL

13

VC

Vital Capacity

Max air which can be moved from deep expiration to deep inspiration.

VC= IRV + Vt +ERV= 4700mL

14

TLC

Tung Lung Capacity

Total volume of air held by the lungs

TLC= IRV + Vt + ERV + RV = 5900mL

15

What method can measure FRC?

Helium dilution

16

FEV1/FVC

Amount of air you can push out in 1 sec/ total amount of air you can push out

should 75-80%

17

Volume of respiratory region (non-dead space)

2.5-3L

18

Methods which can measure RV

-Helium dilution
-Body plethysmography

19

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)

20

Elastic work is proportional to...

Non-elastic work is proportional to...

Elastic --> Tidal Volume

Non-elastic (restriction-based) --> Frequency of Breathing

21

4 Causes for Hypoxemia

(1) Hypoventilation (no change in AaDO2)
(2) Diffusion Limitation (thickness, reduced area, etc.)
(3) Shunt (no change from increased O2)
(4)V/Q inequality

22

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

23

Diving Response

- Initial Hypertension
- Vasoconstriction
- Bradycardia (vagally induced)
- Splenic contraction

24

Hypoxic Loss of Conciousness

20-25mmHg

25

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

26

Fick's Law

The amount of gas transferred is proportional to the area (A), and difference in partial pressure

27

Graham's Law

Describes the factors which aid diffusion; tells us CO2 diffuses 22x better than O2

28

Hypoxic Vasoconstriction

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)

29

Causes of AaDO2

-V/Q inequality
- Anatomic shunt
-Thebesian vessels
- Bronchial/Pulmonary veins

30

Henry's Law

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)

31

Function of CO

In the presence of small amounts of CO, affinity for O2 is greatly enhanced and unloading is prevented (hence suffocation).

32

Chloride Shift

When intracellular [H+] and [HCO3-] increase in erythrocytes, HCO3- diffuses out and Cl- in, to maintain electrical neutrality

33

Haldane effect

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

34

4 Major Types of Tissue Hypoxia

HYPOXIC HYPOXIA (decreased PaO2 leading to leading to insufficient O2 delivery to tissues)

CIRCULATORY HYPOXIA (reduced blood flow to tissues)

ANEMIC HYPOXIA (inability to carry sufficient oxygen)

HISTOTOXIC HYPOXIA (inability to utilize oxygen-- poisoning)