Normal Breathing

Question 1

What initiates inspiration?

Answer 1

Contraction of the diaphragm and external intercostal muscles

Question 2

What happens to the thoracic cavity during inspiration?

Answer 2

expands

Question 3

How does thoracic expansion affect pleural pressure?

Answer 3

Pleural pressure becomes more negative (pressure in thoracic cavity drops)

Question 4

What happens to transmural pressure during inspiration?

Answer 4

increases

Question 5

transmural pressure?

Answer 5

alveolar pressure − pleural pressure

Question 6

How does increased transmural pressure affect the lungs?

Answer 6

expand

Question 7

What happens to intrapulmonary airways during inspiration?

Answer 7

expand due to increased transmural pressure

Question 8

What happens to alveolar volume during inspiration?

Answer 8

Alveolar volume increases

Question 9

How does increased alveolar volume affect alveolar pressure?

Answer 9

Alveolar pressure decreases

Question 10

When does air flow into the lungs during inspiration?

Answer 10

When alveolar pressure falls below atmospheric pressure

Question 11

Which structures are affected by pleural pressure?

Answer 11

Intrapulmonary structures only

Question 12

Which pressure acts on extrathoracic airways?

Answer 12

Atmospheric pressure

Question 13

What happens to extrathoracic airways during inspiration?

Answer 13

constrict

Question 14

Why do extrathoracic airways narrow during inspiration?

Answer 14

Atmospheric pressure exceeds airway pressure → inward collapse tendency

Question 15

what happens to pleural pressure in expiration?

Answer 15

increase

Question 16

what happens to alveolar pressure in expiration?

Answer 16

increase

Question 17

What causes alveolar pressure to rise during expiration?

Answer 17

Elastic recoil of the lungs as pleural pressure increases and lung volume decreases.

Question 18

normal inspiratory-to-expiratory time ratio at rest?

Answer 18

1 : 1.5–2

Question 19

Why does peak inspiratory flow occur late in inspiration?

Answer 19

Intrapulmonary airways progressively expand

Airway resistance decreases as lung volume increases

Flow rises and peaks near end-inspiration

Question 20

Why are inspiratory sounds loudest at end-inspiration?

Answer 20

airflow is highest when airway resistance is lowest near peak lung volume

Question 21

Why does peak expiratory flow occur early in expiration?

Answer 21

Lung elastic recoil is strongest at high lung volumes

Pressure gradient is greatest at the start of expiration

Flow then gradually declines as recoil decreases

Question 22

end-expiratory pause?

Answer 22

A brief period at the end of expiration when:

Alveolar pressure = atmospheric pressure

No net airflow

Question 23

What primarily drives airflow during expiration?

Answer 23

Elastic recoil of the lungs

Question 24

normal bronchovesicular sounds?

Answer 24

Low-pitched, continuous lung sounds heard during normal pulmonary auscultation

Question 25

bronchovesicular sounds originate?

Answer 25

Central and small airways

Question 26

Why do central/small airways generate sound?

Answer 26

Smaller cross-sectional area → higher airflow velocity → turbulence → sound

Question 27

Why are bronchovesicular sounds softer at the chest wall?

Answer 27

filtered by lung parenchyma, reducing intensity

Question 28

How are lung sounds transmitted to the stethoscope?

Answer 28

Conducted through the pleural space and chest wall

Question 29

Are inspiratory or expiratory sounds louder in normal lungs?

Answer 29

Inspiratory sounds > expiratory sounds

Question 30

Why are inspiratory sounds louder than expiratory sounds?

Answer 30

Inspiratory airflow is stronger despite shorter inspiratory time Airways widen during inspiration, reducing resistance and increasing flow

Question 31

Why can normal lung sounds be difficult to detect?

Answer 31

Obesity, thick chest wall, muscle mass, or poor patient cooperation

Question 32

Can upper airway sounds be heard during thoracic auscultation?

Answer 32

yes

Question 33

When are upper airway sounds often louder?

Answer 33

inhalation

Question 34

Where are upper airway sounds loudest on thoracic auscultation?

Answer 34

Thoracic inlet (closest to trachea and larynx)

Question 35

What systems are evaluated during thoracic auscultation?

Answer 35

Cardiac and pulmonary

Question 36

Why is shorter tubing preferred?

Answer 36

Conducts quiet sounds better

Question 37

bell of the stethoscope detect best?

Answer 37

Low-frequency sounds (heart, GI)

Question 38

a tunable diaphragm detect?

Answer 38

Both low- and high-frequency sounds (ideal for lungs)

Question 39

What is proper patient positioning for lung auscultation?

Answer 39

Standing, head up, mouth closed, nasal breathing

Question 40

What pressure should be used for low-frequency sounds?

Answer 40

gentle

Question 41

What pressure should be used for lung sounds?

Answer 41

Firm pressure (reduces low-frequency noise)

Question 42

Where are cranial lung lobes auscultated?

Answer 42

ICS 2–4, mainly ventral

Question 43

What should be heard in cranial lung lobes?

Answer 43

Lung sounds, not heart sounds (cranial to heart)

Question 44

Which regions correspond to right middle and caudal subsegment of left cranial lobe?

Answer 44

ICS 4–6, dorsal and ventral

Question 45

what sounds are expected in ICS 4-6

Answer 45

Mixed lung and heart sounds Lung sounds are quieter Good area for tunable diaphragm: Firm pressure → lung Gentle pressure → heart

Question 46

Where are caudal lung lobes auscultated?

Answer 46

ICS 6–9, dorsal and middle lung fields

Question 47

Why perform cervical auscultation at the thoracic inlet?

Answer 47

To assess referred upper airway sounds

Question 48

Intrathoracic airway obstruction → worse on which flow

Answer 48

exhalation; Pleural pressure > airway pressure → Airway gets compressed from the outside

Question 49

Extrathoracic airway obstruction → worse on which flow

Answer 49

inhalation; airway collapses during inspiration