Week 2 - External respiration
Largest component to air
Nitrogen
What is the air pressure at sea level?
760 mmHg
When oxygen is low, bronchioles will slightly (dilate/constrict), and when oxygen is high, bronchioles will slightly (dilate/constrict).
dilate; constrict
Pulmonary capillaries will respond to oxygen by (constricting/dilating) to increase oxygenation and (constricting/dilating) to reduce oxygenation.
dilating; constricting
What is the protein that helps keep alveoli open?
elastin
The diffusion of oxygen from alveoli into low oxygenated blood coming from the right heart, and the diffusion of that CO2 into the low CO2 compartment inside the alveolus is called ____.
external respiration
Mucus and fluids that are obstructing the airway may (increase/decrease) blood flow to a region, but overall the overall reoxygenation of arterial blood will be (increased/reduced) since air is being obstructed from the mucus and fluids.
increase; reduced
In a highly oxygenated region of the body, an (increase/decrease) in blood flow occurs via (vasoconstriction/vasodilation).
increase; vasodilation
Ventilation perfusion matching (increases/decreases/does not alter) the efficiency of oxygenation of the blood.
increases
When a standing person has increased air flow, which regions of the lungs will get more air?
lower
V/Q mismatch creates (more/less/does not alter) physiologic dead space.
more
A lung infection, such as pneumonia, causes _____, which is when blood flow is normal or may even be increased for some reasons, but air is obstructed from getting into the alveoli.
shunting
Decreased airflow, which reduces the partial pressure of oxygen in a certain region, is going to cause _____ of the pulmonary vessels to decrease blood flow to that area.
vasoconstriction
When oxygen is low, you're going to reduce blood flow to that region by ____.
vasoconstriction
If oxygen is high, you can add more blood to that region by ______.
vasodilation
What important action/s does gravity influence in terms of external respiration?
ventilation and perfusion
What term describes when arterioles in different regions of the lung respond to local oxygen concentration with vasoconstriction when oxygen is low and vasodilation when oxygen is high?
ventilation perfusion matching
External respiration involves the gas exchange at the ______.
alveolar surface
The trachea, the bronchi, the bronchioles, and also the nasal and oral cavities represent ____ in a healthy person.
anatomic dead space
Mucus, diminished surfactant concentration, and decreased alveolar surface area contribute to the ______.
barriers of gas exchange
CO2 that is exhaled comes from the ____.
blood in pulmonary arteries
CO2 represents the waste product of what biochemical process?
cellular metabolism
Partial pressure of water vapor in the lungs
3 to 4 mmHg
Partial pressure of CO2 in the air
0.3 mmHg
After inspiration, there is about ____ of oxygen in the alveolus which will diffuse across into the pulmonary blood, which generally has about ____ of oxygen.
100 mmHg; 40 mmHg
Partial pressure of oxygen in air
159 mmHg
T or F: Oxygen and nitrogen are extremely blood soluble
F
T or F: fluid collection assists in alveolar diffusion
F
T or F: gases in solution are all equally soluble
F
T or F: in a healthy person, anatomic dead space is the same thing as physiologic dead space
F
Why is a bit of inhaled oxygen lost in the conducting zone?
It is displaced from water vapor
What term refers to the concentration of different gases in a mixture?
Partial pressure
T or F: CO2 is extremely blood soluble
T
T or F: gravity influences air and blood coming to the lungs at all times
T
T or F: the respiratory membrane is highly permeable to O2
T
A region where there's ventilation, but there's no blood flow is an example of _____.
pulmonary embolism
A person standing upright will have ____ ventilation in the upper parts of the lung compared to the lower parts of the lung.
reduced
