Regulation of Respiration Flashcards
In the lung where would you find the most compliant alveoli?
base
In the lung, where would you find the lowest arterial BLOOD pressure?
apex
Optimal gas exchange occurs when ventilation is matched to perfusion
awesome
Ventilation to perfusion ratio at the apex is
3.3
ventilation to perfusion ratio at the base is
0.6
V/Q ratio is highest at the apex, therefore,
the apex is “over ventilated and under perfused”
PAO2 difference between apex and base
apex is 132 mmHg and base is 89 mmHg
PACO2 difference between apex and base
apex is 28 mmHg and base is 42 mmHg
difference in O2 in at apex and base
apex is 4 ml/min and base is 60 ml/min
difference in CO2 out at apex and base
apex is 8 ml/min and base is 39 ml/min
The apex has high PAO2 because
all ventilation and no perfusion so O2 is accumulating in the lung due to the high V/Q ratio and no perfusion is moving it away throughout the body
Where in the lung would you find the lowest PACO2?
apex
where in the lung would you find the lowest PAO2?
base
where in the lung would you find the highest O2 uptake?
base
blood leaving the lung has a PaO2 slightly less than PAO2
due to V/Q mismatch and shunting
Control of Respiration
- respiratory muscles require neural stimulation for contraction
- brain establishes the breathing rhythm and force of contraction
- changes in ventilation are assessed by feedback sensors which adjust neural output
Medullary Respiratory Centers:
A. Regulate rhythmicity
B. Activate respiratory muscles
C. Three regulatory regions such as —>
- DRG
- VRG
- Pre-Botzinger
DRG
dorsal diaphragm
primary inspiratory neurons that synapse with motor neurons for inspiration