Why is it more difficult to breathe at higher elevations?
The partial pressure of oxygen is higher at higher elevations; therefore the partial pressure gradient is higher and oxygen moves more quickly into the body.
The partial pressure of oxygen is lower at higher elevations; therefore less oxygen moves into the body down its partial pressure gradient.
The lower partial pressure of oxygen makes it more difficult for alveoli to inflate, making it harder for the body to receive oxygen from air inhaled.
The partial pressure of oxygen is lower at higher elevations, meaning there is less oxygen physically available to consume.
Bergmann's rule states that at _______________ elevations, body shapes tend to be _________________.
what the fuck is a surfactant? what does this have to do with the mammalian respiratory system?
a surfactant is a fluid that lowers the surface tension that is found in the alveoli. this helps mammalian respiratory system by decreasing the amount of pressure needed to inflate alveoli after deflation.
a surfactant is a fluid that is found inside the lining of the lungs. This helps the respiratory system by increasing the amount of oxygen that is pushed into the alveoli.
a surfactant is a a thin layer of molecules that sits inside the alveoli. This helps the respiratory system by decreasing the amount of pressure needed to deflate the alveoli after inflation.
a surfactant is a fluid that binds to incoming oxygen inside the alveoli. this helps the respiratory system by working along a partial pressure gradient and increasing the pressure to help inflate the alveoli.
in which body of water would you expect to have the highest level of oxygenation?
a lake that is at an elevation 3,000 feet above sea level.
a large, shallow pond that is stagnant.
a shallow, small river that has a rapid current with lots of rocks.
a large river that is deep that empties out into the ocean.
fish are known to use up to 20% of the energy in order to breathe in their aquatic environment. Which fish would have the greatest difficulty in breathing due to environmental constraints?
a smaller fish that lives in a shallow, freshwater pond.
a saltwater fish that lives in a tropical ocean reef.
a freshwater fish that lives in a very warm river.
a larger fish that lives in a cool lake with many mineral deposits.
What would you expect natural selection to act upon in Fick's law?
A. the difference in partial pressure of gas on either side of diffusion barrier
B. the amount of surface area available for gas exchange
C. the thickness of the diffusion barrier
both A and B
both B and C
D. the solubility of gas medium
all of the above
an amphibian uses a _____________ to create ______________ pressure to inflate lungs. A human uses _____________ to create _______________ pressure in order to breathe.
oral opening, positive, alveoli, negative
oral opening, negative, alveoli, positive
buccal pump, negative, diaphragm, positive
buccal pump, positive, diaphragm, negative
If an underweight, full term, freshly minted baby has a hard time making its first breath, what might you assume to be true of its respiratory system?
lungs are underdeveloped in baby and the bronchioles are too small in order to allow the necessary ratio of air into the lungs in order to breathe properly.
surfactant development was somehow stunted during pregnancy and the pressure needed to inflate the alveoli is much higher than baby can deal with.
baby doesn't have enough body weight to properly expel the first breath of oxygen to fight the partial pressure gradient of oxygen and carbon dioxide.
baby is underweight and probably had poor nutrition during its pregnancy, which would affect its ability to breathe properly.
why is a bird lung so damn efficient?
A. one way air flow allows more air to come into the lung and allows the bird to extract more oxygen
B. less dead space between the anterior air sacs and the mouth allow birds to use air obtained much more efficiently
C. gas exchange occurs during inhalation and exhalation.
D. air flowing through four different chambers allows the bird to maximize exhalation of carbon dioxide, allowing more oxygen to move into the lungs.
both A and C
both B and C