Week 8 - Control of Ventilation Flashcards
1
Q
What is pneumothorax?
A
- punctured lung
- air enters thorax
- displaces the fluid that bathes lung and keeps it upright
- air pockets press on lungs in thoracic cavity
- prevents lung expansion
2
Q
What is the Hering-Breuer Reflex?
A
- stretch receptors in lung
- prevent overinflation
- and alveoli damage
- negative feedback that cannot be overridden
3
Q
How do central chemoreceptors regulate ventilation?
A
- in medulla oblongata
- CO2 diffuses to CSF (CerebroSpinal Fluid) from capillary
- reacts with H2O
- forms carbonic acid catalysed by carbonic anhydrase
- dissociates into HCO3- and proton
- lowers pH
- sensed by chemoreceptor
- lower pH means more CO2 which means breathe more
4
Q
What is hyperventilation?
A
- rapid breathing
- increased fresh air
- increases diffusion gradient
- reduced blood CO2
- does not increase O2 level
- low O2 (from swimming) but also low CO2 due to hyperventilation
- fainting occurs due to person not having to breathe
5
Q
What are peripheral sensors for ventilation regulation?
A
- in carotid and aortic body
- sense O2 concentration
- emergency system
- slow reaction than central sensor
- measures bound vs unbound Hb
6
Q
How does altitude sickness occur?
A
- unpredictable blood pH flux
- breathing fluctuate between fast and slow
