Biology Ch. 42 Transport Cardiovas (MB)

Atmospheric pressure at sea level is equal to a column of 760 mm Hg. Oxygen makes up 21 percent of the atmosphere by volume. The partial pressure of oxygen (PO2) in such conditions is...

160 mm Hg

At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21 percent oxygen, then the partial pressure of oxygen at this altitude is about...

80 mm Hg

An open circulatory system _____ direct the hemolymph toward specific organs. Also, because the pressure is _____ in an open circulatory system, there is a _____ flow of hemolymph.

An open circulatory system cannot direct the hemolymph toward specific organs. Also, because the pressure is lower in an open circulatory system, there is a slower flow of hemolymph.

Which group has an open circulatory system?

Insects

Why is breathing more difficult at high altitudes, such as at the top of Mount Everest?

The lower partial pressure of oxygen in the atmosphere reduces the rate of diffusion of oxygen into your body. (Differences in partial pressure of gases drive the rate of diffusion. Lower atmospheric pressure means lower oxygen partial pressure, reducing oxygen uptake.)

What is present in arterioles that is NOT present in capillaries?

circular smooth muscles.

Which feature is common to gills, lungs, and tracheae?

lage surface area

Together, the respiratory and circulatory systems function to...

provide oxygen to your tissues and remove carbon dioxide from your body.