Chapter 34
Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries?
Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.
Which statement about lipoproteins is correct?
High-density lipoproteins are cholesterol transporters in the blood.
Dissolved proteins in human plasma include which of the following? I. fibrinogen II. hemoglobin III. immunoglobulin
I and III only
How are gases transported in insect bodies?
In tracheal systems
Which statement about human blood vessels is correct?
Pulmonary veins carry oxygen-rich blood to the heart.
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.
Which of the following organisms has no specialized respiratory structures?
earthworms
Heart rate will increase in the presence of increased
epinephrine.
The hormone that stimulates the production of red blood cells and the organ where this hormone is synthesized are
erythropoietin and kidney, respectively.
The production of red blood cells is stimulated by
erythropoietin.
Dialysis is the process of filtering the blood; it is performed when kidney functionality is below normal. During dialysis, plasma and its proteins are separated from the cells. Dialysis patients, who will have blood withdrawn, dialyzed, and then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave, because
even small changes in body weight may signify changes in blood volume and therefore blood pressure.
The meshwork that forms the fabric of a blood clot is
fibrin.
The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the
fishes.
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.
If, during protein starvation, the osmotic pressure on the venous side of capillary beds drops below the hydrostatic pressure, then
fluids will tend to accumulate in tissues.
To adjust blood pressure independently in the capillaries of the gas-exchange surface and in the capillaries of the general body circulation, an organism would need a(n)
four-chambered heart.
In which of the following organisms does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body?
frogs
Among the following choices, which organism likely has the highest systolic pressure?
giraffe
In which of the following animals are the circulatory fluid and interstitial fluid considered to be the same body fluid?
grasshoppers
The hemocyanin of arthropods and molluscs differs from the hemoglobin of mammals in that
hemocyanin has protein coupled to copper rather than iron.
Hydrogen ions produced within human red blood cells are prevented from significantly lowering plasma pH because they bind to
hemoglobin.
Small swollen areas in the neck, groin, and axillary region are associated with
increased activity of the immune system.
The amount of oxygen bound to hemoglobin _____.
increases in the presence of high concentrations of oxygen
Some human infants, especially those born prematurely, suffer serious respiratory failure because of
lung collapse due to inadequate production of surfactant.
The plasma proteins in humans
maintain the blood's osmotic pressure.
An "internal reservoir" of oxygen in rested muscle is found in oxygen molecules bound to
myoglobin.
Sponges, cnidarians, and flatworms lack a specialized gas exchange surface because
nearly all of their cells are in direct contact with the external environment.
The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in
pH.
Air-breathing insects carry out gas exchange
across the finest branches of the trachea and cell membranes.
In mammals, most gas exchange between the atmosphere and the pulmonary blood occurs in the
alveoli.
A species that has a normal resting systolic blood pressure of >260 mm Hg is likely to be
an animal that has a very long distance between its heart and its brain.
An increase from pH 7.2 to pH 7.4 around hemoglobin causes
an increase in the affinity of hemoglobin to bind oxygen molecules.
A paleontologist discovers the fossilized heart of an extinct animal. The evidence indicates that the organism's heart was large, well formed, and had four chambers, with no connection between the right and left sides. A reasonable conclusion supported by these observations is that the
animal was endothermic and had a high metabolic rate.
Vasoconstriction of blood vessels delivering blood to the gut is a likely response when an individual is
stressed and secreting stress hormones.
The epiglottis of a human covers the glottis when he or she is
swallowing.
Which of the following develops the greatest pressure on the blood in the mammalian aorta?
systole of the left ventricle
What will be the long-term effect of blocking the lymphatic vessels associated with a capillary bed?
the accumulation of more fluid in the interstitial areas
The set of blood vessels with the slowest velocity of blood flow is
the capillaries.
Countercurrent exchange is evident in
the flow of water across the gills of a fish and that of blood within those gills.
The fluid that moves around in the circulatory system of a typical arthropod is
the interstitial fluid.
Of the following choices, impairment of a mammal's breathing cycle is most likely following neural damage in
the medulla oblongata and the pons.
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.
The circulatory system of bony fishes, rays, and sharks is similar to
the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber.
Air rushes into the lungs of humans during inhalation because
the rib muscles and diaphragm contract, increasing the lung volume.
Circulatory systems compensate for
the slow rate at which diffusion occurs over large distances.
The velocity of blood flow is the lowest in capillaries because
the total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries or any other part of the circulatory system.
The set of blood vessels with the lowest blood pressure driving flow is
the veins.
A human red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in the thumb. To travel from the artery in the arm to the left ventricle, this red blood cell must pass through
two capillary beds.
An increased concentration of nitric oxide within a vascular bed is associated with
vasodilation.
Which of the following is the correct sequence of blood flow in reptiles and mammals?
vena cava → right atrium → right ventricle → pulmonary circuit
The blood pressure is lowest in the
vena cava.
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.
An advantage of gas exchange in fresh water, compared with gas exchange in air, is that _____.
water loss through evaporation across the respiratory surface can be minimized
Damage to the sinoatrial node in humans
would disrupt the rate and timing of cardiac muscle contractions.
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.
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 an atmospheric pressure of 870 mm Hg of 21% oxygen, the partial pressure of oxygen is
182 mm Hg.
A patient with a blood pressure of 120/75, a pulse rate of 40 beats/minute, a stroke volume of 70 mL/beat, and a respiratory rate of 25 breaths/minute will have a cardiac output of
2,800 mL/minute.
In a healthy human, the typical life span of a red blood cell is
4 months.
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.
A stroke volume in the heart of 70 mL/cycle, with a pulse of 72 cycles per minute, results in a cardiac output of
5 L/minute.
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.
_____ in carbon dioxide in your red blood cells, which causes _____ in pH, causes your breathing to speed up.
An increase ... a drop
Which of the following best describes an artery?
Arteries carry blood away from the heart.
Breathing is usually regulated by
CO2 and O2 concentration and pH-level sensors.
Select the correct statement about capillary beds.
Capillary beds are the site of nutrient and oxygen delivery to tissues.
Which statement regarding the mammalian heart is correct?
Which statement regarding the mammalian heart is correct?
Countercurrent exchange in the fish gill helps to maximize
diffusion.
Stroke occurs when _____.
a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue
Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have
a closed circulatory system.
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.
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.
The exhalation of air from human lungs is driven by
a decrease in the volume of the thoracic cavity.
An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it
blocks the openings into the tracheal system.
The diagnosis of hypertension in adults is based on the
blood pressure being greater than 140 mm Hg systolic and/or >90 diastolic.
Hemoglobin and hemocyanin
both transport oxygen.
The smallest airway through which inspired air passes before gas exchange occurs in the mammalian lungs is the _____.
bronchiole
During most daily activities, the human respiration rate is most closely linked to the blood levels of
carbon dioxide.
The material present in arterioles that is not present in capillaries is
circular smooth muscle cells that can alter the size of the arterioles.
Most of the carbon dioxide produced by humans is
converted to bicarbonate ions by an enzyme in red blood cells.
Large proteins such as albumin remain in capillaries rather than diffusing out, resulting in the
development of an osmotic pressure difference across capillary walls.
The semilunar valves of the mammalian heart
prevent backflow of blood in the aorta and pulmonary arteries.
Gas exchange in the aquatic salamander known as the axolotl is correctly described as
simple diffusion of oxygen into the salamander from the water.
A group of students was designing an experiment to test the effect of smoking on grass frogs. They hypothesized that keeping the frogs in a smoke-filled environment for defined periods would result in the animals developing lung cancer. However, when they searched for previously published information to shore up their hypothesis, they discovered they were quite wrong in their original assessment. Even though they were never going to go ahead with their experiment (so as not to harm frogs needlessly), they knew that a more likely outcome of putting carcinogens in the air would be the development of
skin cancer.