# Respiratory Gas Exchange

Topics: Oxygen, Gas, Pressure Pages: 2 (311 words) Published: April 19, 2013
The Respiratory System: Gas Exchange
1.The atmosphere is a mixture of gases. Write down the percentages for: a. O2 _____21%______
b. CO2 ____0.04%_______
c. N2 _____78%______
d. H2O _____0.46%______
2.Calculate the partial pressures of the following gases at both atmospheric pressures:
760 mmHg747 mmHg
a. O2 __159.6mmHg_____________156.9mmHg_______
b. CO2 ___.3mmHg_____________.3mmHg______
c. N2 ____597mmHg_____________587mmHg_____
d. H2O ___3.5mmHg________ _3.4mmHg__________ 3.What is the atmospheric pressure on the top of Mt. Whitney? __440mmHg_________ 4.Calculate the partial pressure of O2 on the top of Mt. Whitney. _92_____mmHg 5.a. Why does more CO2 than O2 dissolve in liquid when both gases are at the same pressure?

CO2 is more soluble in liquid than O2
b. Name the law that explains this. _henry’s law_
6.Efficient external respiration depends on three main factors - list them. a. surface areas and structure of the respiratory membrane b. partial pressure gradients
c. matching alveolar air flow to pulmonary capillary blood flow 7.What three factors cause the partial pressures of gases in the alveoli to differ from pressures in the atmosphere? a. humidification of the air

b. gas exchange between capillaries and alveoli
c. making of old and new air
8.When airflow is restricted so that the partial pressure of O2 is low and CO2 is high, what happens to the: a. arterioles? ___vasoconstriction_____________
b. bronchioles? ____dilation____________

9.Internal respiration depends on three factors - list them.
a. available surface area
c. variable rate of blood flow varies
10.The planet Pneumo has a total atmospheric pressure of 900 mmHg. Oxygen and carbon dioxide each constitute 30% of the atmosphere. a. What is the partial pressure of oxygen...