Respiratory System 3

Question 1

define pulmonary gas exchange

Answer 1

movement of gases between blood in pulmonary capillaries and the alveoli of the lungs

Question 2

define tissue gas exchange

Answer 2

movement of respiratory gases between blood in the systemic capillaries and the cells of systemic tissues

Question 3

define Dalton’s Law

Answer 3

total pressure in a mixture of gases is equal to the sum of the individual partial pressures
ex. Pair + Pgas1 + Pgas2 + Pgas3 etc.

Question 4

define partial pressure

Answer 4

the pressure exerted by each gas within a mixture of gases
ex. PO2
Pgas = total pressure x % of gas

Question 5

define atmospheric pressure

Answer 5

total pressure all gases collectively exert in the environment
760 mmHg at seal level

Question 6

define Henry’s Law

Answer 6

at a given temperature, the solubility of a gas is dependent on the partial pressure of the gas in the air and the solubility coefficient of the gas into liquid

Question 7

what is the driving force moving gas into a liquid

Answer 7

partial pressure

Question 8

define solubility coefficient

Answer 8

volume of gas that dissolves in a specified volume of a liquid at a given temperature and pressure

Question 9

order N2, CO2, and O2 from most soluble to least soluble

Answer 9

CO2, O2, N2

Question 10

what does a gas with a lower solubility need to push it into a liquid

Answer 10

larger pressure gradient

Question 11

why are the P of gases in the alveoli different from the atmospheric P of those same gases

Answer 11

there are different percentages of each gas in the air vs the alveoli

Question 12

why are the gas percentages different in different areas

Answer 12

air from environment mixes with the air remaining in the anatomic dead space in the respiratory tract
oxygen diffuses out of alveoli into the blood while carbon dioxide diffuses from the blood into the alveoli
more water vapor is present in the alveoli due to the higher humidity

Question 13

what is the equation for Fick’s law of diffusion

Answer 13

V gas = A/T x D x (P1 - P2)
V = diffusion
A = area
T = thickness
D = diffusion coefficient
P = pressure of a gas

Question 14

what features make the lung well designed for diffusion of gases

Answer 14

large surface area and very thin alveolar membrane

Question 15

define ventilation perfusion coupling

Answer 15

ability of bronchioles to regulate airflow and arterioles to regulate blood flow
V/Q

Question 16

what is the optimal ventilation perfusion coupling

Answer 16

1/1
more or less is less than optimal
bigger ventilation #, more air than blood
bigger perfusion #, more blood than air

Question 17

explain the cycle of pulmonary and tissue gas exchange

Answer 17