Dissolved proteins in human plasma include which of the
following?
I. fibrinogen
II. hemoglobin
III. immunoglobulin
I and III only
The plasma proteins in humans
maintain the blood's osmotic pressure
The production of red blood cells is stimulated by
erythropoietin
The meshwork that forms the fabric of a blood clot is
fibrin
A significant increase in the amount of interstitial fluid surrounding the capillary beds of a human's lungs will cause
a decrease in the amount of oxygen moving from the lungs into the blood
When the air in a testing chamber is specially mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg, then PO2 is
40 mm Hg
The sun shining on a tidal pool during a hot day heats the water. As some water evaporates, the pool becomes saltier, causing
a decrease in its oxygen content
Sponges, cnidarians, and flatworms lack a specialized gas exchange surface because
nearly all of their cells are in direct contact with the external environment
In mammals, most gas exchange between the atmosphere and the pulmonary blood occurs in the
alveoli
Gas exchange is more difficult for aquatic animals with gills than for terrestrial animals with lungs because
water contains much less O2 than air per unit volume
Countercurrent exchange is evident in
the flow of water across the gills of a fish and that of blood within those gills.
Countercurrent exchange in the fish gill helps to maximize
diffusion
Air-breathing insects carry out gas exchange
across the finest branches of the trachea and cell membranes
An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it
blocks the openings into the tracheal system
Atmospheric pressure at sea level is equal to a column of 760 mm Hg. Oxygen makes up 21% of the atmosphere by volume. The partial pressure of oxygen (PO2) in such conditions is
160 mm Hg
Some human infants, especially those born prematurely, suffer serious respiratory failure because of
lung collapse due to inadequate production of surfactant
At an atmospheric pressure of 870 mm Hg of 21% oxygen, the partial pressure of oxygen is
182 mm Hg
At sea level, atmospheric pressure is 760 mm Hg. Oxygen gas is approximately 21% of the total gases in the atmosphere, so the approximate partial pressure of oxygen is
160.0 mm Hg
At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21% oxygen, then the partial pressure of oxygen at this altitude is
80 mm Hg
Of the following choices, impairment of a mammal's breathing cycle is most likely following neural damage in
the medulla oblongata and the pons
Air rushes into the lungs of humans during inhalation because
the rib muscles and diaphragm contract, increasing the lung volume
The exhalation of air from human lungs is driven by
a decrease in the volume of the thoracic cavity
During most daily activities, the human respiration rate is most closely linked to the blood levels of
carbon dioxide
Breathing is usually regulated by
CO2 and O2 concentration and pH-level sensors
Carbon dioxide levels in the blood and cerebrospinal fluid affect their pH. This enables the organism to sense a disturbance in gas levels as
the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing
To become bound to hemoglobin for transport in a mammal, atmospheric molecules of oxygen must cross
five membranes–in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cell–to bind with hemoglobin.
An increase from pH 7.2 to pH 7.4 around hemoglobin causes
an increase in the affinity of hemoglobin to bind oxygen molecules
An "internal reservoir" of oxygen in rested muscle is found in oxygen molecules bound to
myoglobin
Hemoglobin and hemocyanin
both transport oxygen
The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in
pH
Most of the carbon dioxide produced by humans is
converted to bicarbonate ions by an enzyme in red blood cells
Hydrogen ions produced within human red blood cells are prevented from significantly lowering plasma pH because they bind to
hemoglobin
The hemocyanin of arthropods and molluscs differs from the hemoglobin of mammals in that
hemocyanin has protein coupled to copper rather than iron
In an animal species known for endurance running rather than fast sprinting, you would expect to find
a much higher rate of oxygen consumption for its size.
The epiglottis of a human covers the glottis when he or she is
swallowing