A&P2 Chapter 17

25 July 2022
4.7 (114 reviews)
132 test answers

Unlock all answers in this set

Unlock answers (128)
question
The respiratory quotient is calculated as the
answer
ratio of the volume of carbon dioxide per volume of oxygen consumed
question
At sea level, if oxygen is consumed by the body cells at a rate of 300 mL per minute, then how much oxygen diffuses from the alveoli into the blood in the pulmonary capillaries?
answer
300 mL per minute
question
Oxygenated blood is found in which of the following? A) right atrium only B) pulmonary artery only C) pulmonary vein only D) both the right atrium and pulmonary artery E) both the right atrium and pulmonary vein
answer
C) pulmonary vein only
question
Movement of oxygen and carbon dioxide between alveoli and blood occurs by what process?
answer
simple diffusion
question
Which of the following does NOT contribute to the rapid movement of gases into and out of the blood within the lungs? A) permeability of the membrane B) large surface area C) concentration gradient D) thin membrane E) rapid blood flow
answer
E) rapid blood flow
question
At sea level the air pressure which equals 1 atmosphere is
answer
760 mm Hg
question
In a mixture of gases, the driving force for the movement of an individual gas within that mixture is ultimately the
answer
partial pressure of that gas
question
What is the most abundant gas in the air that we breathe?
answer
nitrogen
question
What percentage of air is oxygen?
answer
21%
question
What percentage of air is carbon dioxide?
answer
< 1%
question
What is the partial pressure of oxygen in a gas mixture that is 40% oxygen, 40% argon, and 20% helium, when the total pressure of the gas is 1000 mm Hg?
answer
400 mm Hg
question
What is the partial pressure of oxygen in air at sea level?
answer
160 mm Hg
question
As humidity increases, the partial pressure of oxygen in air
answer
decreases as the total pressure of air remains the same
question
As the air is saturated with water vapor (humidified) upon entry into the conducting pathway, there will be
answer
a decrease in the partial pressure of the remaining gases
question
At equilibrium, the gas molecules that dissolve in solution and those that remain in the gaseous phase are, by definition, at the same
answer
partial pressure
question
The relationship between the concentration of a gas in solution and the partial pressure of that gas can be described by
answer
Henry's law
question
Which of the following can increase the concentration of a particular gas in a solution? A) Increase the volume of the solution only. B) Decrease the concentration of other gases in the solution. C) Increase the volume of the container containing the gas and solution. D) Increase the volume of the gas only. E) Increase the partial pressure of that gas exposed to the solution.
answer
E) increase the partial pressure of that gas exposed to the solution
question
At equilibrium, which of the following statements is TRUE when helium and nitrogen are present in a gas at equal partial pressures over water? A) The partial pressure of nitrogen is greater than the partial pressure of helium. B) The partial pressures of helium and nitrogen in the water are equal. C) The concentrations of helium and nitrogen in both the water and gas are equal. D) The concentrations of helium and nitrogen in the water are equal. E) The concentrations of helium and nitrogen in the gas are equal.
answer
B) the partial pressures of helium and nitrogen in the water are equal
question
Which statement best describes why O2 and CO2 can both be exchanged simultaneously at the alveoli and pulmonary capillaries? A) Blood in the pulmonary capillaries is high in both O2 and CO2 . B) Nitrogen is at a high pressure in both the alveoli and pulmonary capillaries and drives the exchange of O2 and CO2. C) Each gas acts independently and diffuses down its own partial pressure gradient. D) Blood in both the alveoli and pulmonary capillaries is at equilibrium. E) Blood in the alveoli is high in both O2 and CO2
answer
c) each gas acts independently and diffuses down its own partial pressure gradient
question
Which statement best describes the cause of decompression sickness? A) Carbon dioxide is driven into the cardiovascular system and causes acidosis. B) Nitrogen gas bubbles form in the blood, joints, and nervous system as pressure decreases from too fast an ascent. C) Oxygen molecules are so tightly compressed due to pressure exerted by the water column that they cannot deliver oxygen to the tissues. D) Carbon dioxide bubbles come out of solution too quickly and burst blood vessels, especially in the brain. E) The oxygen molecule expands upon ascent and bursts, therefore causing a lack of oxygen to the tissues
answer
B) Nitrogen gas bubbles form in the blood, joints, and nervous system as pressure decreases from too fast an ascent.
question
Gangrene is often caused by anaerobic bacteria deep in tissues that lack adequate blood flow and adequate oxygen supply. Many times, gangrene can be treated by putting the patient into a hyperbaric chamber. Which statement best describes why this type of therapy is effective?
answer
The increased pressure drives more oxygen into the bloodstream and, therefore, anaerobic bacteria cannot survive in the presence of oxygen
question
The mixing of atmospheric air within the dead space of the conducting zone of the lung upon inspiration results in a partial pressure of
answer
oxygen in the alveoli that is lower than atmospheric
question
Which of the following causes a decrease in the PO2 of air as it enters the conducting zone of the lungs? A) warming of the air B) the increasing PCO2 C) humidifying the air D) the consumption of oxygen E) decreasing alveolar PO2
answer
C) humidifying the air
question
Pulmonary edema describes a condition where the uptake of oxygen and unloading of carbon dioxide is reduced as a consequence of a(n)
answer
thickening of the diffusion barrier by fluid accumulation in the alveoli
question
Your patient is in the hospital due to left heart failure. In your observation, you notice that she has a very low pulse oximeter reading, her skin is turning blue, and she appears to be in respiratory distress (rapid shallow breathing). You immediately call the doctor because you recognize that these symptoms indicate ________,a life-threatening situation.
answer
pulmonary edema
question
What is the most common cause of pulmonary edema?
answer
left heart failure
question
) During intense exercise, the metabolic activity of muscle causes ________ in the partial pressure of oxygen in the tissue, ________ the movement of oxygen into the tissue.
answer
a decrease, facilitating
question
Mixed venous blood samples can be taken from which of the following blood vessels?
answer
pulmonary artery
question
The venous blood in the right ventricle is referred to as "mixed" because the blood that enters the hear
answer
comes from tissue with differing metabolic activities
question
What is an increase in alveolar ventilation to match the demands of increased metabolic activity in the cells called?
answer
hyperpnea
question
Hyperventilation would lead to a(n) ________ within the systemic arteries
answer
increase in PO2 and decrease in PCO2
question
Hypoventilation would lead to a(n) ________ within the systemic arteries.
answer
decrease in PO2 and increase in PCO2
question
What is a decrease in carbon dioxide within the blood called?
answer
hypocapnia
question
What percentage of oxygen is transported in the plasma?
answer
1.5%
question
What percentage of oxygen is transported by hemoglobin?
answer
98.5%
question
The majority of oxygen present within the blood is
answer
bound to hemoglobin in RBCs
question
Each ________ on the hemoglobin subunit is capable of binding an oxygen molecule, thereby allowing ________ oxygen to bind with one hemoglobin molecule.
answer
heme, four
question
What is the primary driving force for the binding of oxygen to hemoglobin?
answer
PO2
question
Which statement best describes why the law of mass action explains the loading and unloading of oxygen in hemoglobin? A) As oxygen levels in the pulmonary capillaries decrease, more carbaminohemoglobin is formed due to the concentration of carbon dioxide. B) The mass of both carbon dioxide and oxygen is the same and therefore they exchange at the same rates C) As oxygen level rises, so does the pressure, which breaks the bonds of hemoglobin thereby releasing hemoglobin to the tissues. D) Oxygen has a greater mass than carbon dioxide and therefore can load more quickly than carbon dioxide. E) As oxygen levels in the pulmonary capillaries increase, more oxyhemoglobin is formed. Conversely, as oxygen levels in the systemic capillaries decrease, the reaction reverses and releases oxygen from hemoglobin.
answer
E) As oxygen levels in the pulmonary capillaries increase, more oxyhemoglobin is formed. Conversely, as oxygen levels in the systemic capillaries decrease, the reaction reverses and releases oxygen from hemoglobin.
question
If hemoglobin is saturated (1.3 mL of oxygen per gram) and there are 150 grams of hemoglobin per liter of blood, how much oxygen can be delivered to the tissue if cardiac output is 15 liters per minute?
answer
2925 mL O2/min
question
What is the definition of anemia?
answer
a decrease in the oxygen carrying capacity of the blood
question
What is labored or difficult breathing called?
answer
dyspnea
question
What is a deficiency of oxygen in the tissues called?
answer
hypoxia
question
What is rapid shallow breathing called?
answer
tachypnea
question
What is a decrease in oxygen in the blood called?
answer
hypoxemia
question
As oxygen binds to hemoglobin, the ________ of the hemoglobin molecule will change through a process of ________ such that the binding of oxygen is enhanced
answer
affinity, positive cooperativity
question
Which of the following statements is FALSE regarding a leftward shift in the hemoglobin-oxygen dissociation curve? A) It can be caused by an increase in blood pH. B) It can be caused by an increase in PCO2. C) Oxygen loading onto the hemoglobin is increased. D) Hemoglobin is more saturated at a given PO2. E) Affinity for oxygen is increased.
answer
B) it can be caused by an increase in PCO2
question
Which of the following statements is FALSE regarding a rightward shift in the hemoglobin-oxygen dissociation curve? A) Hemoglobin unloading of oxygen is increased. B) Oxygen loading onto hemoglobin is decreased. C) Affinity for oxygen is decreased. D) A rightward shift usually occurs in active tissue. E) It can be caused by a decrease in 2,3-BPG.
answer
E) It can be caused by a decrease in 2,3-BPG
question
Which of the following will cause a shift in the hemoglobin-oxygen dissociation curve to the right? A) increase in temperature only B) increase in plasma pH only C) increase in 2,3-BPG (2,3-bisphosphoglycerate) only D) both an increase in temperature and an increase in 2,3-BPG E) both an increase in temperature and an increase in plasma pH
answer
D) both an increase in temperature and an increase in 2,3-BPG
question
As it leaves the lung in the pulmonary vein, blood is ________ saturated with oxygen
answer
98%
question
Which of the following increases oxygen unloading from hemoglobin? A) decreased temperature B) increased carbon dioxide in the tissue C) increased oxygen levels in the tissue D) decreased metabolism E) increased blood pH
answer
B) increased carbon dioxide in the tissue
question
Which of the following will increase the unloading of oxygen within the tissue? A) increased hydrogen ion concentration only B) increased PCO2 only C) increased body temperature only D) both increased hydrogen ion concentration and increased body temperature E) increased hydrogen ion concentration, increased body temperature, and increased PCO2
answer
E) increased hydrogen ion concentration, increased body temperature, and increased PCO2
question
Which of the following will increase the loading of oxygen onto the hemoglobin molecule within the lungs? A) increased PCO2 B) increased body temperature C) decreased hydrogen ion concentration D) increased 2,3-bisphosphoglycerate (2,3-BPG) E) decreased pH
answer
C) decreased hydrogen ion concentration
question
In the systemic arteries, the partial pressure of oxygen is approximately ________, and hemoglobin is approximately ________ saturated with oxygen
answer
100 mm Hg, 98%
question
In the pulmonary arteries, the partial pressure of oxygen is approximately ________, and hemoglobin is approximately ________ saturated with oxygen.
answer
40 mm Hg, 75%
question
Which statement best describes why oxygen is unloaded in tissue that is highly active? A) As temperature increases, the Bohr effect causes hemoglobin to release oxygen. B) As temperature increases, the carbamino effect causes hemoglobin to release oxygen. C) Highly active tissues produce more carbon dioxide, which competes for the heme groups in hemoglobin, thereby displacing oxygen. D) As temperature increases, the affinity for oxygen to hemoglobin increases, allowing more oxygen to be carried to the tissues. E) As temperature increases due to increased metabolism, the affinity of hemoglobin for oxygen is decreased.
answer
E) as temperature increases due to increased metabolism, the affinity of hemoglobin for oxygen is decreased
question
Which statement best describes the Bohr effect? A) The Bohr effect refers to a decrease in pH which decreases the affinity of hemoglobin for oxygen. B) The Bohr effect refers to the cascading events that must take place in order to chemically remove oxygen from hemoglobin. C) The Bohr effect refers to the release of a chemical 2,3 BPG from erythrocytes that degrades hemoglobin and releases oxygen. D) The Bohr effect speeds up metabolism and therefore increases the temperature in the body releasing oxygen to the tissues. E) The Bohr effect refers to a decrease in carbon dioxide concentration which decreases the affinity of hemoglobin for oxygen.
answer
A) The Bohr effect refers to a decrease in pH which decreases the affinity of hemoglobin for oxygen
question
The carbamino effect describes a change in the conformation of hemoglobin that is induced by a(n)
answer
increase in CO2
question
Which of the following statements about 2,3-BPG is FALSE? A) 2,3-BPG synthesis is inhibited by high levels of oxyhemoglobin. B) 2,3-BPG increases the affinity of hemoglobin for oxygen. C) 2,3-BPG is produced by red blood cells. D) 2,3-BPG produces a rightward shift in the hemoglobin-oxygen dissociation curve. E) 2,3-BPG is an intermediate of glycolysis.
answer
B) 2,3-BPG increases the affinity of hemoglobin for oxygen.
question
Where in blood does the conversion of CO2 to bicarbonate occur?
answer
erythrocytes
question
What is the primary mechanism of carbon dioxide transport in blood?
answer
as bicarbonate dissolved in the plasma
question
Which statement best describes how people die of carbon monoxide poisoning? A) Carbon monoxide is toxic because it binds more readily to hemoglobin than oxygen, thereby decreasing the oxygen carrying capacity of blood. B) Carbon monoxide causes decompression sickness which can lead to death. C) Carbon monoxide is toxic because it readily picks up oxygen to produce carbon dioxide, causing acidosis and eventual death. D) As the carbon dioxide content of blood increases, a phenomenon known as the Haldane effect converts the excess carbon dioxide to carbon monoxide until it reaches toxic levels. E) Carbon monoxide causes the carbamino effect where carbon dioxide is stripped of an oxygen, producing carbon monoxide.
answer
A) Carbon monoxide is toxic because it binds more readily to hemoglobin than oxygen, thereby decreasing the oxygen carrying capacity of blood.
question
The presence of bicarbonate ions in the blood has an important direct effect, aside from the transport of CO2, that involves
answer
maintaining acid-base balance
question
Within an erythrocyte, the conversion of CO2 to bicarbonate is prevented from reaching equilibrium by the
answer
efflux of bicarbonate from the erythrocyte via the chloride shift
question
The hydrogen ions released by the dissociation of carbonic acid are buffered by their
answer
binding to hemoglobin
question
The Haldane effect describes the increase in the affinity of hemoglobin for CO2 in the presence of a lowered
answer
PO2
question
During quiet breathing, a person's breathing cycle consists of
answer
contraction and relaxation of inspiratory muscles
question
Which of the following nerves has activity during quiet inspiration? A) phrenic nerve only B) internal intercostal nerve only C) external intercostal nerve only D) both the phrenic nerve and internal intercostal nerves E) both the phrenic nerve and external intercostal nerves
answer
E) both the phrenic nerve and external intercostal nerves
question
During active breathing, bursts of action potentials are observed to occur
answer
asynchronously in the inspiratory and expiratory motor neurons
question
The ________ is the respiratory center that appears to facilitate the transition between inspiration and expiration.
answer
pontine respiratory group
question
In the model for quiet breathing, expiration is induced by
answer
abrupt termination of inspiration
question
Coughing is initiated by ________ located in the ________.
answer
irritant receptors, trachea
question
Peripheral chemoreceptors are specialized cells in contact with arterial blood that respond directly to changes in blood
answer
PO2, pH, and PCO2
question
Central chemoreceptors are neurons in the medulla that respond directly to changes in
answer
cerebrospinal fluid pH.
question
Chemoreceptors respond primarily to changes in PCO2 indirectly by its effect on
answer
hydrogen ion concentration.
question
Hyperventilation will cause changes in PCO2 that are detected by the chemoreceptors which causes a(n)
answer
decrease in breathing rate and depth of breathing.
question
Which of the following best describes a chemoreceptor response to PO2? A) Peripheral chemoreceptors respond to small changes in PO2. B) Central chemoreceptors do not respond to changes in PO2. C) Central chemoreceptors respond to only large decreases in PO2. D) Peripheral chemoreceptors respond only indirectly to PO2. E) Peripheral chemoreceptors respond to oxyhemoglobin.
answer
Central chemoreceptors do not respond to changes in PO2.
question
A decrease in PCO2 within the lung will result in a ________ in the pulmonary vasculature and a ________ in the bronchioles
answer
weak vasodilation : bronchoconstriction
question
A local bronchodilation within the alveolus will result in a(n) ________ in the ventilation-perfusion ratio in that region. A vasoconstriction of pulmonary arteriole diameter will result in a(n) ________ in the ventilation-perfusion ratio in that region.
answer
increase : increase
question
The primary effect of increased PO2 in the lungs is to cause ________ which ________ the ventilation-perfusion ratio back to a normal level.
answer
vasodilation : decreases
question
The primary effect of increased PCO2 in the lungs is to cause ________ which ________ the ventilation-perfusion ratio back to a normal level.
answer
bronchodilation : increases
question
What is the normal pH range for blood?
answer
7.38-7.42
question
Which statement best describes the effect on the body due to pH changes either above or below the normal range? A) Changes in pH can only lower pH causing acidosis, meaning organs deteriorate due to high levels of acid. B) pH ranges vary throughout the body; therefore, blood pH has no detrimental effects on the body as it changes pH. C) Changes in pH out of the normal range are normal and will not have any detrimental effects on the body. D) Changes in pH destroy the nephrons of the kidney, making kidney failure is inevitable. E) Changes in pH can denature proteins that serve as enzymes and receptors throughout the body, resulting in widespread effects on the body.
answer
Changes in pH can denature proteins that serve as enzymes and receptors throughout the body, resulting in widespread effects on the body.
question
When the blood becomes ________, it can lead to a depression in the activity of the central nervous system
answer
acidic
question
The buffering capacity of hemoglobin is directly related to its ability to bind with
answer
hydrogen ions.
question
Bicarbonate is an important buffer in blood and its concentration is regulated by the
answer
kidneys.
question
A change in the ratio of bicarbonate to carbon dioxide concentration in the blood will
answer
change blood pH.
question
Respiratory acidosis will result from a(n)
answer
increase in blood CO2 concentration
question
Assuming resting conditions at sea level, what is the partial pressure of oxygen in air?
answer
160 mm Hg
question
Assuming resting conditions at sea level, what is the partial pressure of oxygen in alveoli?
answer
100 mm Hg
question
Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in alveoli?
answer
40 mm Hg
question
Assuming resting conditions at sea level, what is the partial pressure of oxygen in pulmonary veins?
answer
100 mm Hg
question
Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in pulmonary veins?
answer
40 mm Hg
question
Assuming resting conditions at sea level, what is the partial pressure of oxygen in systemic arteries?
answer
100 mm Hg
question
Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in systemic arteries?
answer
40 mm Hg
question
Assuming resting conditions at sea level, what is the partial pressure of oxygen in systemic veins?
answer
40 mm Hg
question
Assuming resting conditions at sea level, what is the partial pressure of carbon dioxide in systemic veins?
answer
46 mm Hg
question
Assuming resting conditions at sea level, what is the partial pressure of oxygen in pulmonary arteries?
answer
40 mm Hg
question
A decrease in the affinity of hemoglobin for oxygen caused by the binding of carbon dioxide to hemoglobin is described by the
answer
carbamino effect
question
A decrease in the affinity of hemoglobin for oxygen caused by the binding of a hydrogen ion to hemoglobin is described by the
answer
Bohr effect.
question
A decrease in the affinity of hemoglobin for carbon dioxide caused by the binding of oxygen to hemoglobin is described by the
answer
carbamino effect.
question
At an altitude where atmospheric pressure is 500 mm Hg, what is the partial pressure of oxygen?
answer
105 mm Hg
question
A decrease in the affinity of oxygen for hemoglobin is reflected as a ________ shift in the hemoglobin-oxygen dissociation curve, which would facilitate the ________ of oxygen.
answer
rightward : unloading
question
What is the partial pressure of nitrogen if it accounts for 20% of a mixed gas with a total pressure of 1000 mm Hg?
answer
200 mm Hg
question
Respiratory acidosis can occur during
answer
hypoventilation.
question
Over a period of time and under resting conditions, the amount of carbon dioxide generated by the body is greater than the amount of oxygen the body consumes.
answer
False
question
The average respiratory quotient at rest and on a mixed diet is 0.5.
answer
False
question
The partial pressure of an individual gas within a mixture of gases is determined by the total pressure of those gases and the fractional concentration of that gas in the mixture.
answer
True
question
The most abundant gas in air is oxygen.
answer
False
question
The percentage of air that is oxygen decreases as altitude increases.
answer
False
question
At the same partial pressure, all gases in a solution will be at equal concentration.
answer
False
question
Dalton's law describes the solubility of a gas in a liquid.
answer
False
question
Oxygen is much more soluble in aqueous solution than carbon dioxide.
answer
False
question
There is a substantial safety margin for the uptake of gases in the alveolus because at rest, blood is completely oxygenated after traveling only 1/3 the length of the pulmonary capillary bed.
answer
True
question
In active skeletal muscle, the gradient for oxygen movement into the muscle is increased by a decreased PO2 within the muscle cell.
answer
True
question
The blood in the pulmonary vein is called mixed venous blood.
answer
False
question
Hyperpnea describes the increase in ventilation that occurs to meet an increase in metabolic demands of the tissues.
answer
True
question
A decrease in oxygen-carrying capacity can result from alterations in hemoglobin structure or concentration.
answer
True
question
Hyperventilation decreases blood pH.
answer
False
question
The compound 2,3-bisphosphoglycerate is a metabolic intermediate of glycolysis within the erythrocyte that can affect the binding of oxygen to hemoglobin.
answer
True
question
Hemoglobin has a greater affinity for oxygen in the lungs than it does in respiring tissue.
answer
True
question
Carbaminohemoglobin is hemoglobin with carbon dioxide bound to it
answer
True
question
The reaction catalyzed by carbonic anhydrase is an irreversible reaction.
answer
False
question
As blood flows through systemic capillaries, carbonic acid dissociates into a bicarbonate ion and a hydrogen ion within the erythrocyte; the bicarbonate is moved out by the chloride shift while the hydrogen ion binds with hemoglobin.
answer
True
question
The Haldane effect refers to the decrease in affinity of oxyhemoglobin for carbon dioxide.
answer
True
question
The Bohr effect describes the effects of pH on the affinity of hemoglobin for oxygen.
answer
True
question
The inspiratory neurons of the ventral and dorsal respiratory groups stimulate motor neurons in the phrenic nerve, which stimulates contraction of the diaphragm.
answer
True
question
The central chemoreceptor responds to hydrogen ions generated from the dissociation of hydrogen from carbonic acid and lactic acid produced by active skeletal muscle.
answer
False
question
The chemoreceptor reflex regulates ventilation primarily through sensing changes in blood PO2.
answer
False
question
The resistance of the airways is controlled by bronchioles that are sensitive to changes in PCO2
answer
True
question
A respiratory acidosis is cause by increased carbon dioxide within the blood
answer
True
question
Hemoglobin can bind O2, CO2 and H+ all at the same time.
answer
False