Ventilation Perfusion Mismatch Flashcards Preview

Respiratory System > Ventilation Perfusion Mismatch > Flashcards

Flashcards in Ventilation Perfusion Mismatch Deck (9)
Loading flashcards...
1
Q

What is ventilation?

A

Amount of air to enter the lungs

2
Q

What is perfusion?

A

Amount of blood flowing to lungs

3
Q

What is the normal V/Q ratio?

A

1

4
Q

What happens with inadequate ventilation?

A

PaCO2 rises
PaO2 falls
New steady state established
Blood equilibriates

5
Q

What happens when alveolar PaO2 falls?

A

Hypoxic vasoconstriction - diverts blood to ventilated alveoli

6
Q

What can cause a V/Q <1 ?

A
Asthma - airway narrowing
COPD - airway collapse
Pneumonia - exudate in alveoli
NRDS - collapse alveoli 
Pulmonary oedema - fluid in alveoli
7
Q

What is the effect of hyperventilation?

A

PCO2 decreases

PO2 normal

8
Q

What occurs when V/Q <1?

A

Low pO2

High pCO2

9
Q

What occurs when V/Q >1?

A

High pO2

Low pCO2