Lung Ventilation Flashcards Preview

ESA 3 - Respiratory System > Lung Ventilation > Flashcards

Flashcards in Lung Ventilation Deck (72)
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1

What happens when the bronchioles in the lungs dilate? 

They increase their volume and lower the pressure inside the lungs, moving air in 

2

What does the parietal pleura secrete? 

Fluid

3

What is the purpose of the fluid secreted by the parietal pleua? 

The surface tension adheres the two pleural layers together 

4

What is the parietal pleura attached to? 

The chest wall 

5

What is the result of the parietal pleura being attached to the chest wall? 

When the chest wall expands, the parietal pleura moves wtih it, as does the visceral pleura 

6

What is the visceral pleura attached too? 

The lung

7

What is the result of the attachment of the visceral pleura to the lung? 

When the chest wall expands, the lung expands 

8

What do the external intercostal muscles do? 

Elevate the ribs in a 'bucket handle' type movement 

9

How much of chest expansion is the chest wall responsible for during quiet respiration? 

30%

10

What does the diaphragm do to expand the chest? 

Contracts and descends 

11

How much of chest expansion is the diaphragm responsible for during quiet respiration? 

70%

12

What muscles are involved in inhalation during quiet breathing? 

  • Diaphragm
  • External intercostals 

 

13

What muscles are involved in exhalation during quiet breathing? 

None 

14

What muscles are involved in inhalation during forced breathing? 

  • Diaphragm 
  • External intercostals 
  • Scalene 
  • Pectoralis minor 
  • Sternocleidomastoid
  • Serratus anterior

 

15

What muscles are involved in exhalation during forced breathing? 

  • Internal intercostals 
  • Innermost intercostals 
  • Abdominal muscles 

16

What happens to blood flowing through alveolar capillaries? 

It picks up oxygen and loses carbon dioxide by diffusion of those gases across the alveolar wall 

17

What is the rate of gas exchange in the alveolar capillaries determined by? 

  • Area available for gas exchange 
  • Resistance to diffusion 
  • Gradient of partial pressure 

 

18

In a normal lung, what is the exchange area? 

Around 80m2

19

What creates the large area for exchange in the lungs? 

The huge number of alveoli

20

In normal lungs, is the area available for exchange a limiting factor on gas exchange? 

No 

21

What provides resistance to diffusion in the alveoli? 

Although the diffusion pathway is short, there are several structures between the alveolar as and the alveolar capillary blood 

22

What must the alveolar gas diffuse through to reach the alveolar capillary blood? 

  1. Gas in the alveoli 
  2. The alveolar epithelial cell 
  3. Interstitial fluid
  4. Capillary endothelial cell
  5. Plasma
  6. RBC membrane 

5 cell membranes, 3 layers of intracellular fluid and 2 layers of extracellular fluid

23

How long is the diffusion distance between alveolar gas and alveolar capillary blood? 

Less than 1 micron

24

What gases must diffuse through the barrier between alveolar gas and alveolar blood?

Oxygen and carbon dioxide 

25

What is the rate of diffusion across the alveoli affected by for most of the barrier (the cells, membranes, and fluid)?

Solubility of gas in water 

26

How does the diffusion rate of carbon dioxide differ from that of oxygen? 

It diffuses 21 types as fast for a given gradient 

27

Why does carbon dioxide diffuse across the alveoli faster than oxygen? 

Because it is more soluble 

28

How much faster than oxygen does carbon dioxide diffuse for a given gradient? 

21 times as fast

29

What is the result on gas exchange at the alveoli of carbon dioxide diffusing much faster than oxygen?

Anything affecting diffusion will only change oxygen transport, as that is limiting (if there is a problem affecting the exchange of gases, oxygen will be affeted first)

30

What must be true of the partial pressure if the tissues of the body are to be properly supplied with oxygen and carbon dioxide? 

The partial pressure of oxygen and carbon dioxide in the alveolar gas must be kept very close to their normal values