PulmonaryVentilation

anatomic dead space

not involved in gas exchange

volume or air that is in conducting airways

physiologic dead space

gas exchange between the alveoli and blood

the portion of alveolar volume with poor V/Q ratio

adequate gas exchange is impossible if physiologic dead space is >60%

mass of a gas that disolves in a fluid at a given temperature varies in direct proprtion to the pressure of gas over liquid

rate of gas diffusion into a fluid depends on two factors

solubility of the gas in fluid

pressure differential between gas above fluid and gas dissolved in fluid

determins the number of molecules that move into or out of a fluid

exchange of gas between lungs and blood is made at the tissue level

expressed in milliliters

elastic and thin walled membranous sacs

surface for gas exchange

blood supply to alveolar tissue is the greatest to any organ in the body

at rest, 250 ml of O2 leave alveoli to blood, and 200 ml of CO2 diffuse into alveoli

during heavy exercise, 25X increase in quantity of oxygen transfer