AP BIOLOGY STUDY GUIDE
RESPIRATORY AND CIRCULATORY
SYSTEMS
1.
Describe gas exchange in the lungs, naming the structures involved and
explaining why the exchange occurs.
2. What
changes occur in the blood if one were to hold ones breath for a period of time?
If one were to breathe rapidly and deeply for a period of time?
3. Trace
the pathway taken by a molecule of oxygen from the time it enters a nostril
until it enters a red blood cell.
4. Why are gills poorly adapted for life on land?
5. How do amphibians compensate for their low efficiency of
lung ventilation?
6. How do
reptiles, birds and mammals improve the efficiency of lung ventilation over
that of amphibians?
7. Often
people who appear to have drowned can be revived, in some cases after being
underwater for as long as half an hour. In every case of full recovery after
extended submergence, however, the person has been submerged in very cold
water. Is this observation consistent with the fact that oxygen is twice as
soluble at 0°C as it is at 30°C?
8. Can you
think of a reason why a circulatory system has not evolved in which oxygen is
actively transported across respiratory membranes, in place of the passive
process of diffusion across these membranes that is universally employed?
9. If by accident your pleural membrane were punctured,
would you be able to breathe?
10. Trace
the path of a drop of blood from the left ventricle to the big toe and back to
the left ventricle, naming the vessels and structures encountered during the
trip.
11. Name
the one artery in the body that does not carry oxygenated blood. Explain why it
does not carry oxygenated blood.
12. How
does lymph differ from blood?
13. Why
are valves needed in veins but not in arteries?
14.
Oxygen-transport pigments are found in crustaceans, but not in insects. Explain
this difference.
15.
Citrate ions (C6H5O7-3) combine
with calcium ions (Ca2+) to form an insoluble product,
2C6H5O7-3
+ 3Ca2+ à Ca3(C6H5O7
)2. Why do you suppose that
a small quantity of sodium or potassium citrate is added to blood collected for
storage in blood banks?
16.
General edema is characteristic of extreme cases of protein deficiency. Can you account for this?
17. Why is
it difficult to see platelets in stained blood slides?
18. Summarize the various mechanisms by which
our circulatory system adjusts to the demands of strenuous exercise.
19. Why
have mammals not improved the efficiency of their circulation by evolving
hearts larger that 0.6% of their body mass?
20.
Instead of evolving an entire second open circulatory system, the lymphatic
system, to collect water lost from the blood plasma during passage through the
capillaries, why haven’t vertebrates simply increased the level of serum
albumin in their blood?
21.
Starving animals often exhibit swollen bodies rather than emaciated ones, in
early stages of their deprivation. Why?
22. The
hearts of the more advanced vertebrates pump blood entirely by pushing action.
Why do you suppose hearts have not evolved that act like suction pumps, drawing
blood into the heart as it expands, rather than pushing it out as the heart
contracts?