Pulmonary blood flow, gas exchange and transport 1 Flashcards Preview

Respiratory Block > Pulmonary blood flow, gas exchange and transport 1 > Flashcards

Flashcards in Pulmonary blood flow, gas exchange and transport 1 Deck (32)
Loading flashcards...
1
Q

Do both alveolar ventilation and compliance incline or decline with height from base of lung to the apex?

A

Decline

2
Q

Bronchial circulation - what is it supplied by? where do these arise?

A

Nutritive

Supplied via bronchial arteries from systemic arteries

3
Q

Pulmonary circulation - Describe the flow and pressure

A

Gas exchange

High flow and low pressure - only 25mmHg

4
Q

What does A stand for?

A

Alveolar

5
Q

What does a stand for?

A

arterial blood

6
Q

What does v stand for?

A

mixed venous blood eg pulmonary artery

7
Q

PACO2

A

Partial pressure of carbon dioxide in aveolar air

8
Q

PaO2

A

Partial pressure of oxygen in arterial blood

9
Q

What 3 things is the rate of diffusion across the membrane directly proportional to?

A

Partial pressure gradient
gas solubility
Available surface area

10
Q

What is the rate of diffusion inversely proportional to?

A

Thickness of the membrane

11
Q

Is oxygen or carbon dioxide more soluble in water?

A

Carbon dioxide

12
Q

Emphysema and PO2

A

Destroys alveoli and reduces surface area

PO2 in alveoli is normal/low and blood is low

13
Q

Fibrotic lung disease and PO2

A

Thick alveolar membrane so low rate of diffusion

Loss of lung compliance effects ventilation. Same values as emphysema

14
Q

Pulmonary oedema and PO2

A

Fluid increases diffusion distance so PO2 in blood low

15
Q

Asthma and PO2

A

Increased airway resistance and decreased ventilation so low PO2 in alveoli and blood

16
Q

Ventilation

A

Air getting into the alveoli

17
Q

Perfusion

A

Local blood flow

18
Q

What are ventilation and perfusion measured in?

A

L/min

19
Q

What is the distribution of blood flow in lungs influenced by? (2)

A

Blood pressure

Alveolar pressure

20
Q

Is blood flow directly or inversely related to vascular resistance?

A

Inversely

21
Q

Base of lung - arterial and alveolar pressure

A

Arterial is higher so vascular resistance is low

22
Q

Apex of lung - arterial and alveolar pressure

A

Alveolar is higher so vascular resistance is high

23
Q

Above what rib shows a serious mismatch in blood flow and ventilation? What is done about this?

A

Rib 3

Auto regulated at apex of lung to correct the ratio

24
Q

If ventilation is greater that perfusion is the ratio greater or less than 1?

A

Greater

25
Q

If perfusion is greater than ventilation is the ratio greater or less than 1?

A

Less

26
Q

What happens if PCO2 is high and PO2 is low?

A

Blood does not get oxygenated and oxygenated blood from other areas is diluted

27
Q

What happens to blood flow and where is it directed when tissue PO2 is low?

A

Underventilated alveoli arterioles constrict to direct blood flow to better ventilated areas

28
Q

What does high PCO2 do the the bronchi?

A

Mild bronchodilation

29
Q

Does constriction in response occur in only systemic vessels, pulmonary vessels or both?

A

Pulmonary only

30
Q

Shunt

A

The passage of blood through areas of the lung that are poorly ventilated (ventilation<

31
Q

Alveolar dead space

A

Alveoli that are ventilated but not perfused

32
Q

Physiological dead space

A

Alveolar DS + Anatomical DS