gas exchange and transport - bpk 142

two sites of gas exchange in the body

• alveolar — capillary membrane in lung

• tissue — capillary membrane in tissue

Movement of molecules across the respiratory membrane are driven by

diffusion

partial pressure

concentration gradient of gases involved in gas exchange

why is it harder to breathe on mt everest?

high altitude, less available o2 → air diffuses outside the lung

Functional residual capacity (FRC)

air left in lungs after exhalation

why is FRC important

• Helps retain stable partial pressure of gas in alveoli

• Prevents lungs from collapsing

Henry’s law

 amount of gas that dissolves in a fluid is a function of pressure above gas and the solubility factor of gas

lung diffusing capacity

how well lungs transfer gases into blood (alveoli to capillary per minute per mmHg)

O2 carrying capacity of Hb

1 gram of Hb can carry 1.34mL of O2

how does oxygen get transported throughout the body

either gets transported via RBCs or gets dissolved in plasma