RESP GX Flashcards
partial pressure of nitrogen in the atmosphere is?
600 mmHg
partial pressure of oxygen in the atmosphere is?
160 mmHg
what are the four important partial pressures to consider?
PO2, PCO2, PH2O, and PN2
PH2O and PN2 are what in the atmosphere?
zero
what is the inhaled partial pressure of oxygen and nitrogen?
O2 is 150 mmHg
N2 is 563 mmHg
typical functional residual capacity?
2.3 L
how many ml of the 500 ml we inhale make it to the alveoli?
350 mL
each breath replace how much of the gas in the lungs?
15%, see below
350/2300
normal alveolar respiration at rest is how much? how much in mL of O2 and CO2 leave the blood?
4.2 L/min
250 mL of O2 enter blood and 200 mL of CO2 leave the blood
during exercise, alveolar ventilation rises to how much? (hint in L/min)
17 L/min
partial pressures of the gases stay the same no what the activity
T/F, CO2 has much higher solubility coefficient than oxygen?
T, more soluble than most gases
imp because this determines how much gas can be found in the plasma
what are the factors that affect diffusion besides partial pressure?
cross sectional
solubility coefficient
distance
molecular weight
what are the partial pressures of oxygen, CO2, nitrogen?
- 0
- 3
- 53
how many alveoli in the two lungs?
300 million
total area of diffusion across the rest units is how much in adults?
50-100 m^2
total amount of blood in the lungs?
60-140 mLs
this can be a limiting factor if increased in diseased states?
diffusional distance
in emphysema what is the limiting factor?
total surface area becomes decreased
what is diffusing capacity?
ability of gas to diffuse from alveoli to blood
what is important to note about diffusing capacity?
its the volume of gas that diffuses through the membrane each minute due to 1 mmHg pressure difference
what is the pressure gradient for oxygen at rest? mean alveolar oxygen pressure? mean capillary oxygen pressure? this meant how much oxygen can diffuse into the blood?
11 mmHg
104 mmHg
93 mmHg
231 ml/min from pressure gradient (11 mmHg) x diffusing capacity (21 mL/min/mmHg)
so during exercise, diffusing capacity for oxygen rises to 65 mL/min/mmHg which equates to 715 mL/min O2 delivered to blood during exercise, what is this increase due to?
opening of previously closed pulmonary capillaries to handle increased CO
better matching of ventilation to perfusion at all alveoli
note that CO2 diffusing capacity increases too
