Mechanics of Breathing

Question 1

What is the relationship between pressure and volume

Answer 1

pressure and volume are inversely proportional

Question 2

For air to move into the lung pressure should be _______ (below or above) atmospheric pressure

Answer 2

below

Question 3

Air moves from a region of ______ pressure to region of ______ pressure

Answer 3

high to low

Question 4

Lung has a tendency to _____

Answer 4

collapse

Question 5

Chest wall has a tendency to ______

Answer 5

expand

Question 6

Which pressure is an index of intrapleural pressure

Answer 6

esophageal pressure

Question 7

True or false,

Intrapleural pressure is higher than alveolar and atmospheric pressure

Answer 7

False. it is lower than both

Question 8

True or False

Gravity and posture affects pleural pressure

Answer 8

True

Question 9

which muscle is the main muscle of inspiration

Answer 9

Diaphragm

Question 10

Why is inspiration mostly affected when the diaphragm is paralyzed?

Answer 10

because the diaphragm is the main muscle of inspiration

Question 11

Which muscles are the accessory muscles of inspiration

Answer 11

sternocleidomastoid and scalene muscles

Question 12

Which muscles are the accessory muscles of expiration

Answer 12

abdominal (rectus abdominus etc.) & internal intercostal muscles

Question 13

What organ muscle or tissue initiates inspiratory effort

Answer 13

brain

Question 14

an increase in thoracic volume results in a ______ in intrapleural pressure

Answer 14

decrease

Question 15

Upon inspiration, transmural pressure ____

Answer 15

increases

Question 16

Alveoli ____ (expand or collapse) in response to increased transmural pressure

Answer 16

Expand

Question 17

During inspiration does alveolar pressure fall below or go above atmospheric pressure

Answer 17

Falls below

Question 18

As you inspire does tidal volume increase or decrease

Answer 18

Increase

Question 19

As you inspire does intrapleural pressure increase or decrease

Answer 19

decrease

Question 20

As you inspire does airflow become negative or positive

Answer 20

negative

Question 21

As you inspire does tidal volume increase or decrease

Answer 21

decrease

Question 22

As you inspire does transmural pressure increase or decrease

Answer 22

increase

Question 23

Lung volume ____ (increases or decreases) with increase in transpulmonary pressure

Answer 23

increases

Question 24

small volume increase is due to opening of ____ airways

Answer 24

proximal

Question 25

In which condition is the lungs more compliant: emphysema or fibrosis

Answer 25

Emphysema

Question 26

the slope of the pressure-volume curve in respiration is a measure of what

Answer 26

compliance

Question 27

When the lungs are inflated with saline is there less or more hysteresis

Answer 27

Less hysteresis

Question 28

Does a saline filled lungs have greater or less surface tension compared to an air filled lung

Answer 28

It has less surface tension

Question 29

When surface tension increases does the lungs collapse or expand

Answer 29

it collapses

Question 30

is pressure directly or indirectly proportional to radius

Answer 30

Indirectly proportional

Question 31

Which two factors aid the stability of the alveoli

Answer 31

Pulmonary surfactant Alveolar interdependence

Question 32

Surfactant increase compliance or elastance

Answer 32

compliance

Question 33

Surfact keeps alveoli dry and hence prevents_____

Answer 33

pulmonary edema

Question 34

how can loss of surfactant lead to pulmonary edema

Answer 34

In the absence of surfactant there is increase in surface tension which increases pressure in the alveoli and this pulls water from pulmonary capillaries to alveoli

Question 35

At volumes above FRC, pressure is ______

Answer 35

positive

Question 36

At volumes below FRC, pressure is ______

Answer 36

negative

Question 37

There is minimal lung volume when the airway pressure is ____-

Answer 37

zero

Question 38

A _______ (negative/positive) pressure indicated the chest wall is trying to expand

Answer 38

negative

Question 39

At what volume does the relaxation pressure become of the chest wall become 0mmHg

Answer 39

75% volume

Question 40

there is a balance between elastic recoil and chest expansion at which point on the pressure-volume curve

Answer 40

at the function residual capacity at 0mmHg

Question 41

Will an increased or decreased radius decrease resistance

Answer 41

increased radius will decrease resistance

Question 42

Air flow is high when , gas density is ______ (high/low) and the tube radius _____ (large/small)

Answer 42

high large

Question 43

transitional flow is seen at which point in vessels

Answer 43

branching points

Question 44

Which sized bronchi have the greatest resistance

Answer 44

medium size

Question 45

4 factors affecting airway resistance

Answer 45

lung volume tone of bronchial smooth muscle density & viscosity of inspired gas chemical irritants