Final Flashcards
Multiple choice practice for BIO100A Final Exam
Increases in which of the following components of Fick’s law of diffusion would NOT result in an increase in gas exchange across a respiratory surface?
Path length
As the length a compound diffuses increased, the rate of diffusion would decrease.
A simple solution to gas exchange in some aquatic animals is to keep the body very thin (shown, a marine flatworm, Pseudodoceros sp.). Which of the statements about water and air (respiratory media) is FALSE?
Limits imposed by the slow diffusion of O2 molecules in water are completely avoided in animals that breathe air.
True:
D. A given volume of water holds much less oxygen than the same volume of air.
E. A fish breathes water.
A. Active transport mechanisms are not directly involved in the diffusion gases across membranes.
B. Aquatic organisms expend more energy moving water across their exchange surface than terrestrial organisms.
Which component of the human respiratory system would collapse due to surface tension if surfactants were not present in the lungs?
Alveoli
A lack of surfactant is associated with respiratory distress syndrome, resulting in an alveolus (the gas exchange surface), which is difficult to inflate (remains collapsed).
Which of the following statements about ventilation of human lungs is FALSE?
Inhalation depends on positive alveolar pressure; exhalation depends on negative alveolar pressure.
This statement is false; the reverse is true. Contraction of the diaphragm produces a negative pressure within the pleural cavities expanding the lungs and reducing pressure, thereby drawing air in. Relaxation of the diaphragm leads to an increase in pressure within the lungs (positive pressure) that forces the air out.
The primary respiratory gas(es) is/are
Oxygen and Carbon Dioxide
Respiratory gases are exchanged between the body fluids of an animal and its environment by
Diffusion
Why is air a better respiratory medium than water?
A. A given volume of air can contain more O2 than the same volume of water.
B. O2 diffuses faster in air than in water.
C. Less work is required to move air over respiratory exchange surfaces.
D. As water temperature increases, less O2 is available.
Breathing in vertebrates other than birds is _______ and is less efficient than gas exchange in fish or birds.
tidal
In mammalian lungs, the gas exchange surface area provided by _______ is enormous.
Alveoli
Two molecules of hemoglobin can bind a maximum of _______ molecules of _______.
Eight respiratory gas molecules
The ability of hemoglobin to pick up or release O2 depends on
the PO2 of its environment.
When is the ventricular blood volume higher?
At the beginning of systole
In the cardiac cycle, when do the atrioventricular valves close?
During systole
The three principle functions of the vertebrate circulatory system are:
Transport, protection, and body temperature regulation
When blood leaves the right ventricle of the mammalian heart, to which location does it flow next?
The kungs
With each heartbeat, the muscle cells coordinate themselves so that each contraction is forceful enough to circulate blood through the entire body. The beat begins in the _____________node, which sets the tempo of each beat, thus giving it the name of pacemaker.
Sinoatrial
How are the blood-circulation system and the lymphatic system related to each other?
Blood carries nutrients and oxygen to cells and removes their waste. The lymphatic system removes bacteria and debris from the blood.
