Respiratory Physiology

Question 1

Conduction Zone

Answer 1

Conduits to gas exchange, including respiratory structures that do not participate in gas exchange.

Question 2

Respiratory Zone

Answer 2

Site of gas exchange

Question 3

How many orders of branching happens in the bronchial tree?

Answer 3

23

Question 4

How many alveoli do the lungs have?

Answer 4

300 million

Question 5

Which type of epithelium are alveolar walls made of?

Answer 5

Squamous epithelium

Type I cells

Question 6

Which cells secrete surfactant?

Answer 6

Type II cuboidal cells

also secrete antimicrobial proteins

Question 7

Left lung anatomy

Answer 7

Smaller

2 lobes separated by oblique fissure

Question 8

Right lung anatomy

Answer 8

3 lobes separated by oblique (inferior) and horizontal fissures (superior)

Question 9

Pleurae

Answer 9

Thin, double layered serosa
Parietal pleura sits on thoracic wall
Visceral pleura on external lung surface
Pleural fluid provides lube and surface tension

Question 10

What is atmospheric pressure at sea level?

Answer 10

P(atm) 760 mm Hg

Question 11

Intrapulmoary pressure

Answer 11

AKA intra-alveolar pressure
Fluctuates with breathing
Always eventually equalizes with P(atm)

Question 12

Intrapleural Pressure

Answer 12

P(ip)  
Pressure in pleural cavity
Fluctuates with breathing
Always a negative pressure 
< Patm and Ppul

Question 13

Two inward forces promoting lung collapse?

Answer 13

Elastic recoil of lungs

Surface tension of alveolar fluid

Question 14

Force that enlarges the lungs?

Answer 14

Elasticity of chest wall pulling lungs outward

Question 15

What happens if P(ip) = P(pul)?

Answer 15

The lungs collapse

Question 16

P(pul) - P(ip) =?

Answer 16

Transpulmonary Pressure

The greater the transpulmonary pressure, the larger the lungs

Question 17

Atelectasis

Answer 17

Lung collapse
Lack or air delivery, collapsed alveoli
Pneumothorax

Question 18

Boyles Law

Answer 18

P1V1 = P2V2

Pressure varies inversely with volume

Question 19

Factors that influence pulmonary ventilation

Answer 19

Airway resistance
Alveolar surface tension
Lung compliance

Question 20

Airway resistance

Answer 20

Friction is the major source

Gas flow is inverse to resistance

Question 21

Where is highest resistance in bronchiole tree?

Answer 21

Medium sized bronchi

Question 22

Where is the least resistance?

Answer 22

Terminal bronchioles

Question 23

Which drug reduces airway resistance?

Answer 23

Epinephrine

Question 24

Lungs with COPD showed __ - __% reduction in the number of terminal bronchioles.

Answer 24

72 - 89%

Question 25

Surfactant

Answer 25

Detergent-like lipid that discourages alveolar collapse. | Produced by type II cells

Question 26

Lung compliance

Answer 26

Normally high | Surfactant helps by reducing surface tension

Question 27

Tidal Volume (TV)

Answer 27

Amount of air inhaled or exhaled with each breath under resting conditions. Average: 500ml

Question 28

Inspiratory reserve volume (IRV)

Answer 28

Amount of air that can be forcefully inhaled after a normal tidal volume inhalation. Male: 3100 Female: 1900

Question 29

Expiratory reserve volume (ERV)

Answer 29

Amount of air that can be forcefully exhaled after a normal tidal volume exhalation. Male: 1200 Female: 700

Question 30

Residual Volume (RV)

Answer 30

Amount of air remaining in the lungs after a forced exhalation average: 1200

Question 31

Inspiratory Capacity (IC)

Answer 31

Tidal volume + IRV

Question 32

Functional residual capacity (FRC)

Answer 32

ERV + RV

Question 33

Vital Capacity (VC)

Answer 33

TV + IRV + ERV

Question 34

Total lung capacity (TLC)

Answer 34

Sum of all lung volumes

Question 35

Average total lung capacity?

Answer 35

Males: 6000 Females: 4200

Question 36

Average volume of dead space?

Answer 36

150 ml

Question 37

N2 %

Answer 37

78.6

Question 38

O2 %

Answer 38

20.9

Question 39

CO2 %

Answer 39

.04

Question 40

H2O %

Answer 40

.46

Question 41

CO2 is ___ times more soluble than O2 in water.

Answer 41

20 times

Question 42

How long does it take for the partial pressures of O2 in the alveoli and blood vessels to reach equilibrium?

Answer 42

.25 seconds | 104 mmHg

Question 43

CO2 diffuses in equal amounts with ?

Answer 43

Oxygen

Question 44

Ventilation-Perfusion Coupling

Answer 44

The amount of gas reaching the alveoli and the amount of blood reaching the alveoli must be equal for efficient has exchange.

Question 45

When alveolar CO2 is high, bronchioles _____.

Answer 45

Dilate

Question 46

When alveolar CO2 is low, bronchioles ______.

Answer 46

Constrict

Question 47

Oxygen autoregulates ______ Diameter.

Answer 47

Arteriole

Question 48

An increase in body temperature shift the curve to the?

Answer 48

Right

Question 49

Decrease in the pH shifts the curve to the?

Answer 49

Right Bohr effect Decreases affinity for O2

Question 50

In what form is CO2 predominantly transported in the blood?

Answer 50

Bicarbonate ions

Question 51

Slow shallow breathing causes pH to?

Answer 51

drop

Question 52

True of false. CO2 is the most powerful factor controlling respiration

Answer 52

true