Control of ventrilation Flashcards
(13 cards)
What is minute ventilation?
Respiratory minute volume (or minute ventilation or minute volume) is the volume of gas inhaled (inhaled minute volume) or exhaled (exhaled minute volume) from a person’s lungs per minute.
What is the equation for minute ventilation?
VE = Breathing frequency (f) X tidal volume (Vt)
What is the alveolar minute ventilation at rest?
3.5L/min at rest (remember not all of the air that we breathe in gets to the lungs due to dead space.
Why is the graph of min ventilation/ arterial PO2 exponential?
If PO2 conc falls then ventilation rapidly increases to get as much air as possible.
This is a protective reflex
By how much can o2 consumption increase during activity?
10 fold
What other times can o2 consumption vary?
Altitude and disease (pulmonary diseases)
Where is the respiratory centre found?
Medulla oblangata and pons
What does the medulla do?
Primary centre- modulates inspiration and expiration cycle.
What does pons do?
regulates medulla
What does the apneustic centre do?
stimulates inspiratory neurones
What does pneumotaxic centre do?
inhibits inspiratory neurones
What are ventral respiratory group (VRG) and dorsal respiratory group (DRG)?
contains neurons that fire during inspiration
What effect does cerebral cortex have on breathing?
Voluntary control over breathing.
CORTICOL - voluntary hyperventilation and voluntary breath holding.
