Respiratory Dr. Nene Block 2

Question 1

What are the parts of the Conducting Zones?

Answer 1

The first 16 generations (bronchi, bronchioles and terminal bronchioles)

Question 2

What are the parts of the Respiratory Zones?

Answer 2

The last 7 generations (respiratory bronchioles, alveolar ducts and sacs) - the transitional and respiratory zone

Question 3

Defense Mechanism in the Respiratory System: What will clear large particles from 10 - 15 MCM?

Answer 3

Coughing, sneezing, upper airways trapping

Question 4

Defense Mechanism in the Respiratory System: What will clear Medium Size particles from 2 - 10 MCM?

Answer 4

Mucociliary transport

Question 5

Defense Mechanism in the Respiratory System: What will clear Small Size particles less than 2 MCM?

Answer 5

Phagocytosis and macrophages

Question 6

What is the measurement of Alveolar P?

Answer 6

Decreases to about -1 cmH2O during inspiration
- Rises to about +1 cmH2O during expiration.

Question 7

What is the measurement of Transpulomary P?

Answer 7

Increases from -5 to -6.5 cmH2O during inspiration
- Returns to pre-inspiratory value at the end of expiration.

Question 8

What is the measurement of Intrapleural P?

Answer 8

Decreases from -5 to -7.5 cmH2O during inspiration
- Returns to pre-inspiratory value during expiration

Question 9

More negative intrapleural P during inspiration produces what?

Answer 9

greater transverse stretch through the airways → ↓ airways resistance

Question 10

What is Surfactant?

Answer 10

It reduces surface tension and increase compliance to decrease work

Question 11

If Lungs have high compliance…..?

Answer 11

High compliance – lungs are easy to expand
Lungs with low compliance need higher transpulmonary P to expand than lungs with higher compliance

Question 12

What disease causes increase in compliance?

Answer 12

Emphysema (↓ elastic fibers), age

Question 13

What is normal compliance?

Answer 13

Normal compliance - 0.2 L/cm H2O (varies with lung volume)

Question 14

What are the causes of decrease in compliance?

Answer 14

Scar tissue in the lungs (TB, fibrosis)
- Pulmonary edema
- Surfactant deficiency
- Impede lung expansion (i.e., paralysis of intercostal muscles)

Question 15

What is lung compliance?

Answer 15

Is expressed as a change in the lung volume (V) per unit change in the transpulmonary P (P): V/P
Is the ease with which an organ can be stretched (is reciprocal of elasticity)

Question 16

What diseases have abnormally high lung compliance (steeper slope) and ↓ tendency of the lungs to collapse?

Answer 16

Obstructive lung diseases
Obstruction disorders will have more air in expiration in the lungs, air trapping, FRC volume is more (the volume after inspiration)

Question 17

What diseases have abnormally low lung compliance?

Answer 17

Restrictive lung diseases
Restrictive disorders will have less air entry and less air going out

Question 18

What are the functions of surfactant, balloon picture!

Answer 18

Prevention of emptying of small alveoli into large alveoli
Mechanism that stabilizes alveoli from collapsing:
↓ in the alveolar size → ↑ concentration of surfactant in the liquid lining → additional reduction in the surface tension and a decrease in the intra-alveolar pressure.
Law of Laplace: P =2T/r (P – pressure, T – surface tension, r – radius)

↓ in the radius of the alveolus → ↑ P in the alveolus → empting of the small alveoli into the bigger ones and their collapse (atelectasis)

Question 19

What factors affect Airway Resistance?

Answer 19

Depends on the tube length, tube radius, & interaction between moving gas molecules

	R = 8 η l	 η – dynamic viscosity π r4              r, l - radius and length of the tube

Turbulent flow increases resistance

Small bronchioles can be occluded by smooth muscle contraction (wall), mucus, or edema of the wall

Question 20

What control does the ANS have on bronchial smooth muscle tone?

Answer 20

Activation of β2 AR → relaxation of smooth muscle fibers → dilation of the airways → ↓ resistance to air flow
Activation of M-cholino-receptors → contractions of smooth muscles in the bronchioles → ↓ diameter of the airways → ↑ resistance to air flow, which helps in distribution of air flow in the lungs (is blocked by atropine)

Question 21

What control does the ANS have on bronchial smooth muscle tone?

Answer 21

Activation of β2 AR → relaxation of smooth muscle fibers → dilation of the airways → ↓ resistance to air flow
Activation of M-cholino-receptors → contractions of smooth muscles in the bronchioles → ↓ diameter of the airways → ↑ resistance to air flow, which helps in distribution of air flow in the lungs (is blocked by atropine)

Question 22

What is Inspiratory Reserve Volume?

Answer 22

The maximum volume of air that can be taken over and above the tidal volume, potential volume at the end of quite inspiration

Question 23

What is Tidal Volume?

Answer 23

the volume of air entering the lungs during single quite inspiration (is equal to the volume which leaves the lungs during quite expiration): 0.5 L (M/F)

Question 24

What is Expiratory Reserve Volume?

Answer 24

The maximal volume of air expelled by active expiration after the end of quite expiration, potential volume at the end of quite expiration

Question 25

What is Inspiratory Capacity?

Answer 25

The maximum volume of gas that can be inspired from the end expiratory position
IC = TV + IRV

Question 26

What is Residual Volume?

Answer 26

The amount of air remaining in the lungs and air ways after a maximal expiratory effort

Question 27

What is Vital Capacity?

Answer 27

The maximal volume of air that a person can expire (regardless of time required) after a maximal inspiration
VC = TV + IRV + ERV

Question 28

What is Functional Residual Capacity?

Answer 28

Normal end expiratory volume
FRC = RV + ERV

Question 29

What is Total Lung Capacity?

Answer 29

The maximal volume of air in the lungs and airway
TLC = VC + RV

Question 30

On the Flow Volume Loop, where is the Effort Independent Region?

Answer 30

To the RIGHT of the curve

Question 31

On the Flow Volume Loop, where is the Expiratory Flow Rate?

Answer 31

To the LEFT of the curve

Question 32

What is the MOA of the Flow Volume Loop?

Answer 32

Mechanism: dynamic airways compression by expiratory effort limits maximal expiratory air flow

Question 33

What is Anatomic dead space?

Answer 33

The volume of the conducting system of the airways (is ventilated but doesn’t take part in gas exchange)
Dead space ventilation = dead space volume x RR = 150 mL x 12 = 1.8 L/min

Question 34

What is Alveolar (functional) dead space?

Answer 34

The volume of alveolar spaces, which are ventilated but not perfused,  0 mL
Alveolar ventilation = (TV – dead space volume) x RR = 350 mL x 12 = 4.2 L/min

Question 35

What are obstructive disorders and what do they do?

Answer 35

↑ in the airway resistance due to narrowing or occlusion of the airways (i.e., asthma, chronic bronchitis, emphysema (only effect DLCO) – distraction of the lung parenchyma, tumors of the bronchial tree) problems in the interstitial lung
Prolonged expiration, decrease in VC and FVC, Increase in TLC, RV and FRC

Question 36

What are Restrictive disorders and what do they do?

Answer 36

Restrictive disorders:
Generalized decrease in all lung compliance (i.e., pulmonary fibrosis, silicosis, TB, lung edema; constriction of the chest cage – kyphosis, scoliosis, fibrotic pleurisy) problems in lung expansion
FEV1 is normal or greater than normal

Question 37

Why does PVR fall as flow increases?

Answer 37

Capillaries that were already open, now distend further.
Capillaries that were formerly closed, now open (recruitment)

Question 38

What chemical factor controls the resistance of blood flow in the pulmonary circuit?

Answer 38

Hypoxic vasoconstriction