Gas Exchange Flashcards
where does gas exchange occur?
at alveoli and target tissues
what is the gas exchange at the tissue called?
cellular respiration
what is the gas exchange at alveoli called?
pulmonary respiration
how does the gas exchange occur?
by passive diffusion across pressure gradient
what is the composition of ambient air?
21% oxygen, 79% nitrogen, and 0.03% carbon dioxide
what is partial pressure
the pressure of each gas within a mixture of gases
what is the partial pressure of O2 in ambient air?
PO2=159mmHg
what is the partial pressure of CO2 in ambient air?
PCO2 = 0.2mmHg
what is the partial pressure of N in ambient air?
PN = 600mmHg
what is the PO2 in alveoli?
PO2 = 100mmHg
what is the PO2 in capillary?
PO2 = 40 mmHg
what is the PCO2 in alveoli?
PCO2 = 40 mmHg
what is the PCO2 in capillary?
PCO2 = 46 mmHg
How is hyperventilation triggered?
anxiety attacks, fever, aspirin poisoning, or done on purpose.
why breathe into a paper bag when hyperventilating?
Because breathing into a closed space recycles the CO2 which is breathed out, which speeds up how the central chemoreceptors in the ventral part of medulla oblongata trigger and increase breathing rate.
how long can you hold a breath before the urge to breathe
40 seconds
what is the greatest drive to breath?
increase in PCO2 and H (more acidic)
decrease in PO2 (minor)
what happens in hyperventilation
when you increase your rate of ventilation, more CO2 is breathed out then what is needed to be removed, hence pushing the urge to breathe trigger to later
what kind of athlete use hyperventilation?
swimmers and divers
What is shallow water blackout
Happens when a swimmer or diver hyperventilate before training, causing their trigger to breath to be delayed to after the optimal trigger for oxygen consumption, resulting in blacking out under water. This is very dangerous and should always be done under supervision.
