Card Set Information
why no longer hold breath at breaking point?
hypoxia is when ___ and is detected by_____
PO2 too low
hypercapnia is when ___ and is detected by ____
PCO2 too high
proprioceptive influences come from the _____ and makes the px ____
diaphragm and chest wall
why able to extend period of holding after air expiration?
diaphragm was moved
decreased stimulation of proprioceptive receptors
did hyperventilation allow prolonged breath hold and why?
hypercapnia drive removed
increased hypoxia tolerance
did starting lung vol affect breath holding time and why
more vol = more O2 in lungs = can hold for longer
why are we not allowed to hyperventilate with pure O2?
low CO2 = decr hypercapnic drive to breathe
high O2 = decr hypoxic drive to breathe
low lung volume = lung collapse
how long can hold breath if hyperventilate on pure O2
why do swimmers hyperventilate and why is it dangerous?
can hold breath longer
may faint underwater
what happens to PCO2 and PO2 during swimming?
it doubles under water as increased pressure
goes to levels where breathing is needed
resurface = halves pressure = too low
factors influencing breaking point
change in gas volume
tensions of gases stimulate these receptors
carotid and aortic bodies