Pulmonary 1

Question 1

Inspiratory Reserve Volume (IRV)

Answer 1

The additional volume person is CAPABLE of inhaling after normal, quiet inhalation

Question 2

Tidal Volume (TV)

Answer 2

Volume of air inhaled and exhaled during normal breathing ~500mL

Question 3

Residual Volume (RV)

Answer 3

Volume remaining in lungs after maximal exhalation

Question 4

Expiratory Reserve Volume (ERV)

Answer 4

The additional volume person is CAPABLE of exhaling after normal, quiet exhalation

Question 5

Total Lung Capacity (TLC)

Answer 5

Volume of gas in lungs after maximal inhalation
~7L
TLC = TV + RV + ERV + IRV

Question 6

Vital Capacity (VC)

Answer 6

Max volume of air that can be exhaled AFTER maximal inhalation

VC = TV + IRV + ERV

Question 7

Functional Vital Capacity (FVC)

Answer 7

Vital Capacity measured at maximum force

Question 8

Inspiratory Capacity (IC)

Answer 8

Maximum volume that can be inspired after expiration after normal quiet breathing

IC = TV + IRV

Question 9

Functional Residual Capacity (FRC)

Answer 9

Volume remaining in lungs after normal TV exhaled

FRC = ERV + RV

With Helium:
(C1)(VS) = (C2)(VS + FRC)
FRC = (VS) x (C1/C2-1)

Question 10

Define the Conducting and Gas exchange Airways

Answer 10

Conducting
Mouth to Terminal Bronchioles
ONLY air movement
No Gas Exchange
Branch up to 23 times
Radius decreases with each branch
Anatomical Dead Space ~150 mL

Gas Exchange Airway
Respiratory bronchioles to Alveoli
GAS EXCHANGE/Surfactant production

Question 11

Type I and Type II alveolar cells

Answer 11

Epithelial cells

Type I = GAS EXCHANGE
Very Thin

Type II = SURFACTANT
NO Gas Exchange

Question 12

Two important concepts about the lungs from top to bottom

Answer 12

1. Gravity- Blood pressure will be lower at the top and Higer at the bottom
2. Stretch- Amount of stretch from top to bottom depends on the mass below that point (SLINKY)

Question 13

Resistance and area, formula and relationship

Answer 13

R ~ 1/A

Area = (Pie)r2

R ~ 1/(Pie)r2 or R ~ 1/r2

Resistance in the conducting zone will increase with each branch until we get to the Respiratory zone where surface area greatly increases and resistance is almost nothing.

Question 14

Two Important cells in conducting airways

Answer 14

Goblet cells- produce mucus
Prevents large things like
sand from getting to alveoli
Everywhere above alveoli
Including respiratory bronchioles
Ciliated cells move mucous up and out
Located where goblet cells are

Question 15

Alveolar macrophages

Answer 15

Dust cells- Phagocytose Pathogens

Question 16

Clara Cells and Goblet cells relationship

Answer 16

Clara cell are secretary cells in terminal bronchioles, they increase in number the further down we are in the bronchioles, while, goblet cells decrease/are absent in terminal bronchioles

Question 17

Kulchitke cells

Answer 17

Neuroendocrine cells secrete paracrine factors and part of diffuse neuroendocrine system.

Question 18

Relationship of pressure flow and resistance in lungs.

Answer 18

Pulmonary circulation is low pressure, low resistance and high flow, think Ohms law (Flow equals change in pressure over resistance)

Best vascularized area in body, 100% ob blood from RA goes through the lungs which is the same as the mat of blood gsong through the rest of the body. It MUST BE LOW RESISTANCE

If we decrease resistance, we increase flow. Ohms law

Question 19

Important features of Respiratory Zone.

Answer 19

1. Respiratory bronchioles and alveolar ducts
2. Cross sectional area increases, but MOST IMPORTANTLY - Surface area increases allowing for gas exchange
3. Velocity of flow decreases-gas stops and comes back out
4. Ficks

Question 20

Ficks Principal

Answer 20

Ficks = (Area)(Diffusion)(C1-C2)
———————————-
T

C = concentration or it can be pressure P1-P2
T= Thickness of membrane
Thinner the wall, easier the gas exchange
Larger the area the greater the gas exchange
Diffusion = how well a particular molecule diffuses

Question 21

Fused Basal Lamina

Answer 21

Basement membrane of capillary lumen and Type I cells of alveoli fuse together to form fused basal lamina. Used for gas exchange.

Question 22

Whole Body Plethymograpy

Answer 22

Based on Boyle’s law

P1)(V1) = (P2)(V2
Used for measuring FRC

Question 23

What can Spirometry measure an not measure

Answer 23

It can measure all the components of Vital Capacity (TV, ERV, IRV)

It CANNOT measure residual volume so we measure functional residual capacity with helium

Question 24

What are the primary functions of FRC?

Answer 24

1. O2 reserve/bank when needed
2. Keeps intrapleural pressure negative
3. IS maximizes FRC
4. Point when elastic recoil and chest wall are balanced

Question 25

Ventilation of exhaled air

MINUTE VENTILATION

Answer 25

Ve = R x VT

Ve is always larger than Va because some air is in the conducting airways

Ve~7.5 L/min (500 L/breath, 15 breaths/min)

Question 26

Alveolar ventilation

Answer 26

Ventilation of respiratory zones of the lungs

Va = R (VT - VD)

Va = Ve - VD

Va ~
VD~ 150 ml/breath, at 15 breaths per minute VD is approximately 2.25 L/min

Question 27

Determining Dead Space

Answer 27

Volume of Gas that does not eliminate Co2

VD = PaCo2 - PECo2
—– ———————-
VT PaCo2

Simplified:

VD = VT x PaCo2 - PECo2
———————-
PaCo2

PaCo2 = Arterial Co2
PECo2 = Exhaled Co2
Assume arterial Co2 = Alveolar Co2

Question 28

Partial pressures of room air compared to that of inspired gas

Answer 28

Room Air = 21% O2 and 79% N2
Ptot = (0.21 x 760) + (0.79 x 760)

Inspired gas = is humidified
H2O takes up ~ 47mm Hg
Ptot still must equal 760

PItot = 47mmhg
+ (0.21 x (760-47))
+ (0.79 x (760- 47))

If someone has a fever the partial pressure of H2O will increase leaving less room for O2

Question 29

What is unique about the

Pressure of alveolar O2

Answer 29

Must consider the exchange of O2 and Co2.
Assume PaCo2 = PACo2
arterial = Alveolar
Must consider metabolism as well
Respiratory exchange quotient = 0.8 on a mixed diet

PAO2 = PIO2 - (PaCo2 / R)
= 150 - 50
= 100
So from a blood gas we can figure out PAO2
This will also change at different altitudes

Question 30

Alveolar gas equation at SEA LEVEL

Define each equation

Answer 30

PAO2 = FiO2 x (760-47) - pACo2/R

~100mmHg

PAO2 = partial pressure of alveolar oxygen
FiO2 = Fractional concentration of inspired O2
760 = total brometric pressure of the atmosphere at sea level in mmHg
47 Partial pressure of water vapor in alveolus pACo2 = Partial pressure of Co2 coming from blood in mmHg
R = Respiratory exchange quotient

Question 31

What is the Respiratory exchange quotient?

Answer 31

The amount of Co2 generated per O2 molecule utilized

At basal metabolic rate it is 0.8

Question 32

What is the pressure of Arterial 02

Answer 32

In a healthy inividual at sea level ~95 mmHg

Question 33

What is a normal Alveolo-arterial gradient

When will it change

Answer 33

Alveolar pressure at sea level is ~100, so the Alveoli-arterial gradient ranges from 5-10 mmHg

It is INCREASED when there is a diffusion problem, Alveolus to artery

Problem in ANY non-ventilated or poor diffusion space

Question 34

DLco and related formulas

What will make DLco cage and why?

Answer 34

DLco = (A/T) x Dco

DLco = Vco /PAco

we get values using Ficks law
Vgas = A x Diffusion constant X (P1-P2)
———————————————–
Thickness

Deco give us lung diffusion for for CO and tells us how well gasses (O2) will diffuse across a membrane

DLco DECREAESES as someone gets sick- as someone gets thicker O2 will struggle more to cross the membrane than CO2, this is because CO2 is soluble in blood

This is why we give O2 - OXYGEN will help if diffusion is really poor

Question 35

Explain the lung Zones

Answer 35

Zone I = alveoli most stretched and capillaries most compressed (Low ventilation because alveoli already stretched, least profusion)

Zone II =Alveoli mediumly stretched and capillaries medium size

Zone III = Alveoli least stretch and blood vessels largest. (Most Profusion, most ventilation because the smaller UNSTRETCHED alveoli will get the most flow)