PULMONARY 09: EXTREME CONDITIONS Flashcards
Primary physiological responses to high altitude (3)
Hyperventilation
polycythemia
pulmonary vasoconstriction
What is the main problem with high altitude?
Low PO2
What is the most important immediate adaption to high altitude?
Hyperventilation
When you are at high altitude, what are your immediate and long term responses chemically speaking (not big things, molecule size)
Hypoxia is immediately sensed by peripheral chemoreceptors
CO2 is brought back to normal over coming days
If you stay at high altitude, what changes physiologically are you expecting to see in your blood?
Polycythemia, increases o2 concentration in the blood
Although this is positive at first, it can result in pathological increased viscosity of blood
What pathological outcomes can alveolar hypoxia at high altitudes result in?
pulmonary vasoconstriction increases afterload which leads to Right heart hypertrophy and pulmonary edema
The diving Response includes what 3 main elements
- closure of upper airways
- splenic contraction to increase RBC/Hb in blood
- Cardiovascular outcomes like bradycardia and vasoconstriction to redistribute blood to heart and brain
What is the outcome of hyperventilation prior to diving, with regard to the drive to breathe?
It inhibits CO2-driven drive to ventilate. This can be negative becauseyou might not realize you’re as low on oxygen as you are until it’s too late
What causes ascent blackout / hypoxia of ascent?
A drop in PaO2 as ambient pressure is reduced during ascent
Following deep diving, decompression sickness occurs due to what forming in tisues?
N2 bubbles
At high pressures, what kind of toxicity do N2 and O2 give on the tisues of the body?
N2 and O2 will affect the CNS (inert gas narcosis) and O2 will affect the lung
