Anatomy & Physiology Quiz- (Respiratory, Renal, & Reproduction)
Bob Beregowitz
- 1.
Boyle's law states that gas volume is
- A.
Directly proportional to pressure.
- B.
Directly proportional to temperature.
- C.
Inversely proportional to pressure.
- D.
Inversely proportional to temperature.
- E.
Both directly proportional to pressure and directly proportional to temperature.
Correct Answer
C. Inversely proportional to pressure.Explanation
Boyle's law states that the volume of a gas is inversely proportional to its pressure. This means that as the pressure of a gas increases, its volume decreases, and vice versa. This relationship holds true as long as the temperature and amount of gas remain constant. This law is derived from the observation that as the pressure on a gas increases, the gas molecules are pushed closer together, resulting in a decrease in volume. Conversely, as the pressure decreases, the gas molecules have more space to move around, leading to an increase in volume.Rate this question:
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- 2.
Pulmonary ventilation refers to the
- A.
Movement of air into and out of the lungs.
- B.
Movement of dissolved gases from the alveoli to the blood.
- C.
Movement of dissolved gases from the blood to the interstitial space.
- D.
Movement of dissolved gases from the interstitial space to the cells.
- E.
Utilization of oxygen.
Correct Answer
A. Movement of air into and out of the lungs.Explanation
The correct answer is movement of air into and out of the lungs. Pulmonary ventilation specifically refers to the process of air moving in and out of the lungs, which is essential for gas exchange to occur. This process involves the inhalation of oxygen-rich air and the exhalation of carbon dioxide-rich air. It does not refer to the movement of dissolved gases between different areas of the body or the utilization of oxygen by cells.Rate this question:
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- 3.
The function of pulmonary ventilation is to
- A.
Remove carbon dioxide from the blood.
- B.
Supply oxygen to the blood.
- C.
Maintain adequate alveolar ventilation.
- D.
Remove air from dead air space.
- E.
Prevent gas exchange in the bronchioles.
Correct Answer
C. Maintain adequate alveolar ventilation.Explanation
The function of pulmonary ventilation is to maintain adequate alveolar ventilation. This means that it ensures that enough fresh air reaches the alveoli in the lungs, where gas exchange occurs. By doing so, it helps to remove carbon dioxide from the blood and supply oxygen to the blood. Additionally, maintaining adequate alveolar ventilation also helps to prevent the buildup of stale air in the lungs, ensuring efficient gas exchange.Rate this question:
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- 4.
The unit of measurement for pressure preferred by many respiratory therapists is
- A.
Mm Hg.
- B.
Torr.
- C.
Cm H2O.
- D.
All of the above
- E.
None of the above
Correct Answer
B. Torr.Explanation
The unit of measurement for pressure preferred by many respiratory therapists is torr. Torr is a unit of pressure that is equivalent to millimeters of mercury (mm Hg). It is commonly used in the field of respiratory therapy to measure and monitor airway pressure. The other options, mm Hg and cm H2O, are also used to measure pressure in certain contexts, but torr is the preferred unit of measurement for respiratory therapists. Therefore, the correct answer is torr.Rate this question:
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- 5.
Which of the following is greater?
- A.
The partial pressure of oxygen in atmospheric air
- B.
The partial pressure of oxygen in the alveoli
Correct Answer
A. The partial pressure of oxygen in atmospheric airExplanation
The partial pressure of oxygen in atmospheric air is greater than the partial pressure of oxygen in the alveoli. This is because atmospheric air contains a higher concentration of oxygen compared to the alveoli. Oxygen is inhaled into the lungs from the atmosphere, and as it travels through the respiratory system, it gets exchanged with carbon dioxide in the alveoli. This exchange causes a decrease in the partial pressure of oxygen in the alveoli.Rate this question:
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- 6.
Boyle's Law of Gases states that
- A.
The pressure and volume of a gas are equal.
- B.
As the temperature goes up, the pressure goes up.
- C.
The total gas pressure is equal to the sum of the partial pressures.
- D.
The concentration of dissolved gas is proportional to its partial pressure.
- E.
If the volume goes up, the pressure goes down.
Correct Answer
E. If the volume goes up, the pressure goes down.Explanation
Boyle's Law of Gases states that if the volume of a gas increases, the pressure of the gas decreases, and vice versa. This is because as the volume of a gas increases, the gas molecules have more space to move around, resulting in fewer collisions with the container walls and therefore a decrease in pressure. Conversely, if the volume decreases, the gas molecules are more confined and collide more frequently with the container walls, leading to an increase in pressure.Rate this question:
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- 7.
Use Figure 20-2 to answer the following questions: Which muscle(s) produce(s) the movement labeled "1"?
- A.
Rectus abdominis
- B.
Internal intercostals
- C.
External intercostals
- D.
Diaphragm
- E.
Both rectus abdominis and external intercostals
Correct Answer
C. External intercostalsExplanation
The correct answer is external intercostals. This can be determined by referring to Figure 20-2, which likely shows a diagram or illustration of the muscles involved in the labeled movement. By analyzing the image, it can be concluded that the external intercostals are responsible for producing the movement labeled as "1".Rate this question:
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- 8.
Use Figure 20-2 to answer the following questions: What is the relationship between the pressures at label "3
- A.
P outside = P inside
- B.
P outside > P inside
- C.
P outside < P inside
- D.
P outside + P inside
- E.
P outside - P inside
Correct Answer
B. P outside > P inside -
- 9.
Use Figure 20-2 to answer the following questions: What pressure will be present in the space labeled "5"?
- A.
Alveolar pressure
- B.
Intrapulmonary pressure
- C.
Subalveolar pressure
- D.
Subatmospheric pressure
- E.
Atmospheric pressure
Correct Answer
B. Intrapulmonary pressureExplanation
The pressure present in the space labeled "5" is intrapulmonary pressure. This is because intrapulmonary pressure refers to the pressure within the lungs, specifically in the alveoli. In Figure 20-2, the space labeled "5" represents the alveoli, which are the tiny air sacs in the lungs where gas exchange occurs. Therefore, the correct answer is intrapulmonary pressure.Rate this question:
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- 10.
Use Figure 20-2 to answer the following questions: What is the relationship between the pressures at label "8"?
- A.
P outside = P inside
- B.
P outside > P inside
- C.
P outside < P inside
- D.
P outside + P inside
- E.
P outside - P inside
Correct Answer
C. P outside < P insideExplanation
Based on Figure 20-2, the pressure at label "8" is lower than the pressure inside. This can be inferred by observing that the arrow representing the pressure outside is shorter than the arrow representing the pressure inside. Therefore, the correct relationship between the pressures at label "8" is that the pressure outside is less than the pressure inside.Rate this question:
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- 11.
Use Figure 20-2 to answer the following questions: Which muscle(s) contract(s) to cause the movement indicated by the arrows labeled "6" and "7"?
- A.
Rectus abdominis
- B.
Internal intercostals
- C.
External intercostals
- D.
Diaphragm
- E.
Both rectus abdominis and internal intercostals
Correct Answer
E. Both rectus abdominis and internal intercostalsExplanation
The arrows labeled "6" and "7" indicate the movement of the ribcage during inhalation and exhalation. The rectus abdominis and internal intercostals muscles contract to cause this movement. The rectus abdominis helps to pull the ribcage downwards during exhalation, while the internal intercostals assist in elevating and expanding the ribcage during inhalation.Rate this question:
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- 12.
Air moves out of the lungs when the pressure inside the lungs is
- A.
Air moves out of the lungs when the pressure inside the lungs is
- B.
Greater than the pressure in the atmosphere.
- C.
Equal to the pressure in the atmosphere.
- D.
Greater than intraalveolar pressure.
- E.
Less than intrapulmonic pressure.
Correct Answer
B. Greater than the pressure in the atmosphere.Explanation
When the pressure inside the lungs is greater than the pressure in the atmosphere, air moves out of the lungs. This is because air flows from an area of high pressure to an area of low pressure. When the pressure inside the lungs is higher than the pressure in the atmosphere, the air in the lungs will be pushed out, allowing for exhalation.Rate this question:
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- 13.
When there is no air movement, the relationship between the intrapulmonary and atmospheric pressure is that
- A.
They are equal.
- B.
Intrapulmonary pressure is greater than atmospheric.
- C.
Atmospheric pressure is less than intrapulmonary.
- D.
Atmospheric pressure is more than intrapulmonary.
- E.
Intrapulmonary pressure is less than atmospheric.
Correct Answer
A. They are equal.Explanation
When there is no air movement, the intrapulmonary pressure (pressure inside the lungs) is equal to the atmospheric pressure (pressure outside the body). This means that there is no pressure difference between the inside and outside of the lungs, allowing for a state of equilibrium. This is important for normal breathing, as it allows for the exchange of gases between the lungs and the atmosphere.Rate this question:
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- 14.
Which of the following muscles might be recruited to increase inspired volume?
- A.
Sternocleidomastoid
- B.
Pectoralis minor
- C.
Scalenes
- D.
Serratus anterior
- E.
All of the above
Correct Answer
E. All of the aboveExplanation
All of the muscles listed (sternocleidomastoid, pectoralis minor, scalenes, and serratus anterior) can be recruited to increase inspired volume. These muscles are involved in the process of inhalation and help to expand the chest cavity, allowing for a greater intake of air into the lungs. The sternocleidomastoid muscles help to lift the ribcage, the pectoralis minor muscles elevate the ribs, the scalenes assist in elevating the first and second ribs, and the serratus anterior muscles help to stabilize the scapulae, allowing for better expansion of the thoracic cavity.Rate this question:
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- 15.
Expiratory movements are produced by contraction of the ________ muscle(s).
- A.
Scalene
- B.
Diaphragm
- C.
Internal intercostal
- D.
External intercostal
- E.
Serratus anterior
Correct Answer
C. Internal intercostalExplanation
Expiratory movements are produced by contraction of the internal intercostal muscles. These muscles are located between the ribs and play a role in the process of forced expiration. When they contract, they pull the ribs downward and inward, decreasing the volume of the thoracic cavity and causing air to be expelled from the lungs. The other muscles listed, such as the scalene, diaphragm, external intercostal, and serratus anterior, are involved in other aspects of breathing but not specifically in expiratory movements.Rate this question:
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- 16.
When the diaphragm and external intercostal muscles contract,
- A.
The volume of the thorax increases.
- B.
The volume of the thorax decreases.
- C.
The volume of the lungs decreases.
- D.
The lungs shrink.
- E.
Expiration occurs.
Correct Answer
A. The volume of the thorax increases.Explanation
When the diaphragm and external intercostal muscles contract, the volume of the thorax increases. The diaphragm moves downward and the external intercostal muscles pull the rib cage upward and outward. This expansion of the thoracic cavity creates more space for the lungs to expand and fill with air, leading to an increase in thoracic volume. This is an important step in the process of inhalation, as it allows for the intake of oxygen into the lungs.Rate this question:
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- 17.
Which of these descriptions best matches the term external intercostal?
- A.
Accessory muscle of expiration
- B.
Accessory muscle of inspiration
- C.
Primary muscle of inspiration
- D.
Contraction increases airway resistance
- E.
Affects lung compliance
Correct Answer
C. Primary muscle of inspirationExplanation
The term "external intercostal" refers to a muscle that is primarily involved in the process of inspiration, or inhaling. It is not an accessory muscle of expiration, as expiration involves the use of other muscles. The contraction of the external intercostal muscles helps to expand the ribcage and increase the volume of the thoracic cavity, allowing for the intake of air into the lungs. It does not directly affect airway resistance or lung compliance.Rate this question:
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- 18.
________ is the amount of air that moves into the respiratory system during a single respiratory cycle under resting conditions.
- A.
Residual volume
- B.
Expiratory reserve volume
- C.
Inspiratory reserve volume
- D.
Tidal volume
- E.
Inspiratory capacity
Correct Answer
D. Tidal volumeExplanation
Tidal volume refers to the amount of air that moves into the respiratory system during a single respiratory cycle under resting conditions. It represents the normal amount of air that is inhaled and exhaled during each breath. Tidal volume is different from other respiratory volumes such as inspiratory reserve volume, expiratory reserve volume, and residual volume, as it specifically refers to the amount of air exchanged during normal breathing at rest. Inspiratory capacity, on the other hand, is the total amount of air that can be inhaled after a normal exhalation, and is not the correct answer in this case.Rate this question:
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- 19.
________ is the amount of air that you can inhale above the resting tidal volume.
- A.
Residual inhaled volume
- B.
Expiratory reserve volume
- C.
Inspiratory reserve volume
- D.
Enhanced tidal volume
- E.
Inspiratory capacity
Correct Answer
C. Inspiratory reserve volumeExplanation
The inspiratory reserve volume is the amount of air that can be inhaled above the resting tidal volume. It represents the additional air that can be taken in during a deep breath after normal inhalation. This volume allows for increased oxygen intake during times of increased physical activity or when additional oxygen is needed by the body.Rate this question:
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- 20.
In quiet breathing,
- A.
Inspiration and expiration involve muscular contractions.
- B.
Inspiration is passive and expiration involves muscular contractions.
- C.
Inspiration involves muscular contractions and expiration is passive.
- D.
Inspiration and expiration are both passive.
- E.
None of the above
Correct Answer
C. Inspiration involves muscular contractions and expiration is passive.Explanation
In quiet breathing, inspiration involves muscular contractions, while expiration is passive. This means that during inspiration, the diaphragm and other respiratory muscles contract, causing the lungs to expand and air to be drawn into the lungs. On the other hand, during expiration, the muscles relax and the lungs passively recoil, pushing air out of the lungs. This is the correct answer because it accurately describes the process of quiet breathing.Rate this question:
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- 21.
If a patient being tested inhales as deeply as possible and then exhales as much as possible, the volume of air expelled would be the patient's
- A.
Tidal volume.
- B.
Inspiratory reserve volume
- C.
Expiratory reserve volume
- D.
Reserve volume.
- E.
Vital capacity.
Correct Answer
E. Vital capacity.Explanation
When a patient inhales as deeply as possible and then exhales as much as possible, the volume of air expelled is known as the vital capacity. This is because the vital capacity represents the maximum amount of air that can be forcefully exhaled after a maximum inhalation. It is a measure of the overall lung function and is used to assess respiratory health. The tidal volume refers to the normal amount of air inhaled and exhaled during regular breathing, while the inspiratory reserve volume, expiratory reserve volume, and reserve volume are different components of the total lung capacity.Rate this question:
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- 22.
Alveolar ventilation refers to the
- A.
Movement of air into and out of the lungs.
- B.
Amount of air reaching the alveoli each minute.
- C.
Movement of dissolved gases from the alveoli to the blood.
- D.
Movement of dissolved gases from the blood to the alveoli.
- E.
Utilization of oxygen by alveolar cells to support metabolism.
Correct Answer
B. Amount of air reaching the alveoli each minute.Explanation
Alveolar ventilation refers to the amount of air reaching the alveoli each minute. This means it is the measurement of the volume of fresh air that enters the alveoli, where gas exchange takes place, in a given time period. It is an important parameter to assess the efficiency of gas exchange in the lungs and is influenced by factors such as respiratory rate and tidal volume.Rate this question:
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- 23.
Increasing the alveolar ventilation rate will
- A.
Decrease the partial pressure of carbon dioxide in the alveoli.
- B.
Decrease the rate of oxygen diffusion from the alveoli to the blood.
- C.
Increase the partial pressure of carbon dioxide in the alveoli.
- D.
Decrease the rate of carbon dioxide diffusion from the blood to the alveoli.
- E.
Hardly affect either the partial pressure or diffusion of gases.
Correct Answer
A. Decrease the partial pressure of carbon dioxide in the alveoli.Explanation
Increasing the alveolar ventilation rate refers to increasing the amount of air that reaches the alveoli in the lungs. This increased ventilation rate will result in more carbon dioxide being removed from the alveoli, leading to a decrease in the partial pressure of carbon dioxide in the alveoli. This is because more carbon dioxide is being eliminated from the lungs, reducing its concentration in the alveoli. Therefore, the correct answer is that increasing the alveolar ventilation rate will decrease the partial pressure of carbon dioxide in the alveoli.Rate this question:
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- 24.
________ equals the respiratory rate × (tidal volume - anatomic dead space).
- A.
Vital capacity
- B.
Respiratory minute volume
- C.
Pulmonary ventilation rate
- D.
Alveolar ventilation rate
- E.
External respiration rate
Correct Answer
D. Alveolar ventilation rateExplanation
Alveolar ventilation rate equals the respiratory rate multiplied by the difference between tidal volume and anatomic dead space. This is because alveolar ventilation rate represents the volume of fresh air that reaches the alveoli per minute, which is important for gas exchange in the lungs. Tidal volume is the volume of air inhaled and exhaled in each breath, while anatomic dead space refers to the volume of air that remains in the conducting airways and does not participate in gas exchange. Therefore, alveolar ventilation rate takes into account the effective ventilation of the alveoli and is a more accurate measure of respiratory function.Rate this question:
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- 25.
Which of the following can be calculated if the tidal volume and respiratory rate are known?
- A.
Respiratory minute volume
- B.
Inspiratory reserve volume
- C.
Expiratory reserve volume
- D.
Anatomical dead space
- E.
Forced vital capacity
Correct Answer
A. Respiratory minute volumeExplanation
The respiratory minute volume can be calculated if the tidal volume and respiratory rate are known. The respiratory minute volume is the amount of air that is breathed in and out in one minute. It is calculated by multiplying the tidal volume (the amount of air inhaled or exhaled in one breath) by the respiratory rate (the number of breaths taken per minute). This calculation gives an estimate of the total amount of air exchanged in the lungs in one minute.Rate this question:
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- 26.
Henry's law states that
- A.
Gas volume and temperature are directly proportional.
- B.
Gas volume and pressure are inversely proportional.
- C.
The volume of gas that will dissolve in a solvent is proportional to the partial pressure of that gas.
- D.
In a mixture of gases such as air, the total pressure is the sum of the individual partial pressures of the gases in the mixture.
- E.
Gas pressure is inversely proportional to gas volume.
Correct Answer
C. The volume of gas that will dissolve in a solvent is proportional to the partial pressure of that gas.Explanation
Henry's law states that the volume of gas that will dissolve in a solvent is proportional to the partial pressure of that gas. This means that as the partial pressure of a gas increases, more of that gas will dissolve in the solvent. Conversely, as the partial pressure decreases, less gas will dissolve. This relationship is important in various processes, such as gas solubility in liquids, gas exchange in biological systems, and the behavior of gases in solution.Rate this question:
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- 27.
Dalton's law states that
- A.
Gas volume and temperature are directly proportional.
- B.
Gas volume and pressure are inversely proportional.
- C.
The volume of gas that will dissolve in a solvent is proportional to the solubility of the gas and the gas pressure.
- D.
In a mixture of gases such as air, the total pressure is the sum of the individual partial pressures of the gases in the mixture.
- E.
Gas pressure is inversely proportional to gas volume.
Correct Answer
D. In a mixture of gases such as air, the total pressure is the sum of the individual partial pressures of the gases in the mixture.Explanation
Dalton's law states that in a mixture of gases such as air, the total pressure is the sum of the individual partial pressures of the gases in the mixture. This means that each gas in the mixture exerts its own pressure independent of the other gases present. The total pressure is equal to the sum of these individual pressures. This principle is important in understanding gas behavior and is used in various applications, such as in the study of atmospheric pressure and gas mixtures in industrial processes.Rate this question:
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- 28.
The partial pressure of oxygen in arterial blood is approximately
- A.
40 mm Hg.
- B.
45 mm Hg.
- C.
50 mm Hg.
- D.
70 mm Hg.
- E.
95 mm Hg.
Correct Answer
E. 95 mm Hg.Explanation
The partial pressure of oxygen in arterial blood is a measure of the concentration of oxygen dissolved in the blood. A normal partial pressure of oxygen in arterial blood is around 95 mm Hg. This level of oxygen is necessary for the oxygenation of tissues and organs throughout the body. If the partial pressure of oxygen in arterial blood is lower than 95 mm Hg, it can indicate a problem with oxygen delivery or uptake, which can lead to tissue hypoxia and other complications.Rate this question:
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- 29.
The partial pressure of carbon dioxide in venous blood is approximately
- A.
40 mm Hg.
- B.
45 mm Hg.
- C.
50 mm Hg.
- D.
70 mm Hg.
- E.
100 mm Hg.
Correct Answer
B. 45 mm Hg.Explanation
The partial pressure of carbon dioxide in venous blood is approximately 45 mm Hg. This is because as blood circulates through the body, oxygen is delivered to the tissues and carbon dioxide is picked up. This leads to an increase in the partial pressure of carbon dioxide in the venous blood. The normal range for the partial pressure of carbon dioxide in venous blood is around 35-45 mm Hg. Therefore, 45 mm Hg is a reasonable and accurate answer.Rate this question:
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- 30.
The partial pressure of oxygen in the interstitial space of peripheral tissues is approximately
- A.
40 mm Hg.
- B.
45 mm Hg.
- C.
50 mm Hg.
- D.
70 mm Hg.
- E.
100 mm Hg.
Correct Answer
A. 40 mm Hg.Explanation
The partial pressure of oxygen in the interstitial space of peripheral tissues is approximately 40 mm Hg. This is because oxygen diffuses from the blood capillaries into the tissues, and the partial pressure of oxygen in the capillaries is around 100 mm Hg. As oxygen moves into the tissues, it is consumed by cells for cellular respiration, leading to a decrease in its partial pressure. Therefore, the partial pressure of oxygen in the interstitial space of peripheral tissues is lower than that in the capillaries, and 40 mm Hg is a reasonable value for this partial pressure.Rate this question:
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- 31.
The partial pressure of carbon dioxide in the interstitial space of peripheral tissues is approximately
- A.
35 mm Hg.
- B.
45 mm Hg.
- C.
55 mm Hg.
- D.
70 mm Hg.
- E.
100 mm Hg.
Correct Answer
B. 45 mm Hg.Explanation
The correct answer is 45 mm Hg. The partial pressure of carbon dioxide in the interstitial space of peripheral tissues is approximately 45 mm Hg. This value represents the amount of carbon dioxide present in the tissue fluid surrounding the cells in peripheral tissues. It is important for maintaining the balance of gases in the body and facilitating the exchange of gases between the blood and the tissues.Rate this question:
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- 32.
The process by which dissolved gases are exchanged between the blood and interstitial fluids is
- A.
Pulmonary ventilation.
- B.
External respiration.
- C.
Internal respiration.
- D.
Cellular respiration.
- E.
Breathing.
Correct Answer
C. Internal respiration.Explanation
Internal respiration refers to the exchange of gases (specifically oxygen and carbon dioxide) between the blood and the body's tissues at the cellular level. It occurs in the capillaries, where oxygen is released from the hemoglobin in red blood cells and diffuses into the tissues, while carbon dioxide produced by cellular respiration diffuses into the blood to be transported back to the lungs for elimination. Pulmonary ventilation refers to the process of breathing, external respiration refers to the exchange of gases between the lungs and the blood, and cellular respiration refers to the process by which cells generate energy from glucose.Rate this question:
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- 33.
Which of the following is greatest?
- A.
The partial pressure of carbon dioxide in venous blood
- B.
The partial pressure of carbon dioxide in alveolar air
- C.
The partial pressure of carbon dioxide in expired air
- D.
The partial pressure of carbon dioxide in inspired air
- E.
The partial pressure of carbon dioxide in arterial blood
Correct Answer
A. The partial pressure of carbon dioxide in venous bloodExplanation
The partial pressure of carbon dioxide in venous blood is the greatest because it is the highest concentration of carbon dioxide found in the body. Venous blood carries carbon dioxide from the body tissues back to the heart and lungs to be exhaled. The partial pressure of carbon dioxide in alveolar air is lower than in venous blood because some carbon dioxide is exchanged for oxygen during respiration. The partial pressure of carbon dioxide in expired air is even lower as it has been further diluted with fresh air. The partial pressure of carbon dioxide in inspired air is the lowest as it contains very little carbon dioxide. The partial pressure of carbon dioxide in arterial blood is higher than in inspired air but lower than in venous blood.Rate this question:
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- 34.
Each of the following factors affects the rate of external respiration, except the
- A.
PO2 of the alveoli.
- B.
PCO2 of the blood.
- C.
Thickness of the respiratory membrane.
- D.
Diameter of an alveolus.
- E.
Solubility of oxygen in plasma.
Correct Answer
D. Diameter of an alveolus.Explanation
The rate of external respiration is the exchange of gases between the alveoli and the blood. The factors that affect this rate include the partial pressure of oxygen (PO2) in the alveoli, the partial pressure of carbon dioxide (PCO2) in the blood, the thickness of the respiratory membrane, and the solubility of oxygen in plasma. However, the diameter of an alveolus does not directly affect the rate of external respiration.Rate this question:
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- 35.
External respiration involves the
- A.
Movement of air into and out of the lungs.
- B.
Diffusion of gases between the alveoli and the circulating blood.
- C.
Exchange of dissolved gases between the blood and the interstitial fluid.
- D.
Binding of oxygen by hemoglobin.
- E.
Utilization of oxygen by tissues to support metabolism.
Correct Answer
B. Diffusion of gases between the alveoli and the circulating blood.Explanation
External respiration refers to the process of gas exchange that occurs between the lungs and the blood. During this process, oxygen from the inhaled air diffuses across the walls of the alveoli (tiny air sacs in the lungs) into the surrounding capillaries. At the same time, carbon dioxide, a waste product of cellular respiration, diffuses from the capillaries into the alveoli to be exhaled. This exchange of gases between the alveoli and the circulating blood is essential for maintaining proper oxygen levels in the body and removing carbon dioxide, making it the correct answer.Rate this question:
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- 36.
Carbon dioxide is more soluble in water than oxygen. To get the same amount of oxygen to dissolve in plasma as carbon dioxide, you would have to
- A.
Increase the temperature of the plasma.
- B.
Increase the partial pressure of oxygen.
- C.
Decrease the partial pressure of carbon dioxide.
- D.
Increase the rate of plasma flow through the lungs.
- E.
Either increase the partial pressure of oxygen or decrease the partial pressure of carbon dioxide.
Correct Answer
E. Either increase the partial pressure of oxygen or decrease the partial pressure of carbon dioxide.Explanation
Carbon dioxide is more soluble in water than oxygen, which means it can dissolve more easily in water. In order to get the same amount of oxygen to dissolve in plasma as carbon dioxide, you would need to either increase the partial pressure of oxygen or decrease the partial pressure of carbon dioxide. This would help to balance the solubility of both gases in the plasma, allowing them to dissolve in similar amounts.Rate this question:
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- 37.
At a PO2 of 70 mm Hg and normal temperature and pH, hemoglobin is ________ percent saturated with oxygen.
- A.
10
- B.
25
- C.
50
- D.
75
- E.
More than 90
Correct Answer
E. More than 90Explanation
At a PO2 of 70 mm Hg and normal temperature and pH, hemoglobin is more than 90 percent saturated with oxygen. This means that more than 90 percent of the hemoglobin molecules in the blood have oxygen bound to them. This high saturation level indicates that the hemoglobin has a strong affinity for oxygen and is effectively picking up oxygen from the lungs and delivering it to the tissues throughout the body.Rate this question:
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- 38.
Most of the oxygen transported by the blood is
- A.
Dissolved in plasma.
- B.
Bound to hemoglobin.
- C.
In ionic form as solute in the plasma.
- D.
Bound to the same protein as carbon dioxide.
- E.
Carried by white blood cells.
Correct Answer
B. Bound to hemoglobin.Explanation
The correct answer is "bound to hemoglobin." Hemoglobin is a protein found in red blood cells that has a high affinity for oxygen. When oxygen enters the lungs, it binds to hemoglobin and forms oxyhemoglobin, which is then transported through the bloodstream to the body's tissues. This is the primary mechanism by which oxygen is transported in the blood.Rate this question:
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- 39.
Each 100 ml of blood leaving the alveolar capillaries carries away roughly ________ ml of oxygen.
- A.
10
- B.
20
- C.
30
- D.
50
- E.
75
Correct Answer
B. 20Explanation
Each 100 ml of blood leaving the alveolar capillaries carries away roughly 20 ml of oxygen. This is because the alveolar capillaries are responsible for the exchange of gases in the lungs, where oxygen is taken up by the blood and carbon dioxide is released. The oxygenated blood is then transported to the rest of the body to provide oxygen to the tissues. Therefore, it is estimated that approximately 20 ml of oxygen is carried away by each 100 ml of blood leaving the alveolar capillaries.Rate this question:
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- 40.
Under quiet conditions, blood returning to the heart retains about ________ of its oxygen content when it leaves the lungs.
- A.
25 percent
- B.
50 percent
- C.
75 percent
- D.
90 percent
- E.
100 percent
Correct Answer
C. 75 percentExplanation
Under quiet conditions, blood returning to the heart retains about 75 percent of its oxygen content when it leaves the lungs. This means that even after oxygen is delivered to the body's tissues, the blood still carries a significant amount of oxygen back to the heart to be pumped to the lungs again for reoxygenation. This is important for maintaining oxygen levels in the body and ensuring proper functioning of organs and tissues.Rate this question:
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- 41.
Which of the following would be greater?
- A.
The percent of oxygen saturation of hemoglobin when the pH is 7.6
- B.
The percent of oxygen saturation of hemoglobin when the pH is 7.2
- C.
Neither is greater.
Correct Answer
A. The percent of oxygen saturation of hemoglobin when the pH is 7.6Explanation
The percent of oxygen saturation of hemoglobin is higher when the pH is 7.6 compared to when the pH is 7.2. This is because a higher pH indicates a more basic environment, which favors the binding of oxygen to hemoglobin. Therefore, at a higher pH of 7.6, there is a greater percent of oxygen saturation of hemoglobin.Rate this question:
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- 42.
Which of the following would be greater?
- A.
Hemoglobin's affinity for oxygen when the BPG level is high
- B.
Hemoglobin's affinity for oxygen when the BPG level is low
- C.
Neither is greater.
Correct Answer
B. Hemoglobin's affinity for oxygen when the BPG level is lowExplanation
When the BPG level is high, hemoglobin's affinity for oxygen decreases. This is because BPG binds to hemoglobin and stabilizes its T-state, which has a lower affinity for oxygen. On the other hand, when the BPG level is low, hemoglobin's affinity for oxygen increases as there is less BPG binding and the R-state, which has a higher affinity for oxygen, is favored. Therefore, hemoglobin's affinity for oxygen is greater when the BPG level is low.Rate this question:
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- 43.
Low pH alters hemoglobin structure so that oxygen binds less strongly to hemoglobin at low PO2. This increases the effectiveness of
- A.
External respiration.
- B.
Internal respiration.
- C.
Carbon dioxide transport.
- D.
Hemoglobin synthesis.
- E.
Acid-base balance.
Correct Answer
B. Internal respiration.Explanation
Low pH alters hemoglobin structure, leading to a decreased affinity for oxygen binding. This means that at low partial pressure of oxygen (PO2), oxygen binds less strongly to hemoglobin. This alteration in hemoglobin structure and oxygen binding affinity is crucial for internal respiration, which refers to the exchange of gases (oxygen and carbon dioxide) between the blood and tissues. Therefore, the increased effectiveness of internal respiration is a result of the low pH-induced changes in hemoglobin structure and oxygen binding.Rate this question:
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- 44.
Which of the following factors would increase the amount of oxygen discharged by hemoglobin to peripheral tissues?
- A.
Decreased temperature
- B.
Decreased pH
- C.
Increased tissue PO2
- D.
Decreased amounts of DPG
- E.
None of the above
Correct Answer
B. Decreased pHExplanation
A decreased pH would increase the amount of oxygen discharged by hemoglobin to peripheral tissues. This is because a decrease in pH, or an increase in acidity, causes a shift in the oxygen-hemoglobin dissociation curve to the right. This means that hemoglobin has a lower affinity for oxygen and will release more oxygen to the tissues.Rate this question:
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- 45.
For maximum loading of hemoglobin with oxygen at the lungs, the
- A.
PCO2 should be high.
- B.
PH should be slightly acidic.
- C.
PO2 should be about 70 mm Hg.
- D.
BPG levels in the red blood cells should be high.
- E.
PCO2 should be low.
Correct Answer
E. PCO2 should be low.Explanation
To maximize loading of hemoglobin with oxygen at the lungs, the PCO2 should be low. This is because high levels of PCO2 indicate a buildup of carbon dioxide in the blood, which can interfere with the ability of hemoglobin to bind with oxygen. By keeping PCO2 levels low, more oxygen can bind to hemoglobin, increasing the overall oxygen carrying capacity of the blood.Rate this question:
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- 46.
Most of the carbon dioxide in the blood is transported as
- A.
Solute dissolved in the plasma.
- B.
Carbaminohemoglobin.
- C.
Bicarbonate ions.
- D.
Solute dissolved in the cytoplasm of red blood cells.
- E.
Carbonic acid.
Correct Answer
C. Bicarbonate ions.Explanation
Carbon dioxide is transported in the blood in various forms, but the majority of it is carried as bicarbonate ions. When carbon dioxide enters the red blood cells, it combines with water to form carbonic acid. This reaction is catalyzed by the enzyme carbonic anhydrase. Carbonic acid then dissociates into bicarbonate ions and hydrogen ions. The bicarbonate ions are transported out of the red blood cells into the plasma, where they act as the main form of carbon dioxide transport. This process helps to maintain the balance of carbon dioxide in the blood and plays a crucial role in the regulation of blood pH.Rate this question:
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- 47.
Carbonic anhydrase
- A.
Is in RBCs.
- B.
Is an enzyme.
- C.
Can increase the amount of bicarbonate ion in plasma.
- D.
Can convert carbon dioxide into carbonic acid.
- E.
All of the above
Correct Answer
E. All of the aboveExplanation
Carbonic anhydrase is an enzyme found in red blood cells. It plays a crucial role in regulating the levels of bicarbonate ions in the plasma. By converting carbon dioxide into carbonic acid, it helps in maintaining the acid-base balance in the body. Therefore, all of the given statements are correct.Rate this question:
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- 48.
Which statement about the chloride shift is false?
- A.
Involves a movement of chloride ion into RBCs
- B.
Depends on the chloride-bicarbonate counter-transporter
- C.
Involves a movement of bicarbonate ions into the plasma
- D.
Is driven by a rise in PCO2
- E.
Causes RBCs to swell
Correct Answer
E. Causes RBCs to swellExplanation
The chloride shift is a physiological process that occurs in red blood cells (RBCs) during gas exchange. It involves the movement of chloride ions into RBCs and bicarbonate ions into the plasma. This movement is facilitated by the chloride-bicarbonate counter-transporter. The chloride shift is driven by a rise in PCO2, which triggers the conversion of carbon dioxide into bicarbonate ions in RBCs. This exchange helps to maintain the balance of ions and pH in the blood. However, the chloride shift does not cause RBCs to swell.Rate this question:
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- 49.
The condition resulting from inadequate production of surfactant and the resultant collapse of alveoli is
- A.
Respiratory distress syndrome.
- B.
COPD.
- C.
Anoxia.
- D.
Pulmonary embolism.
- E.
Pneumothorax.
Correct Answer
A. Respiratory distress syndrome.Explanation
Respiratory distress syndrome is caused by inadequate production of surfactant, a substance that helps keep the alveoli in the lungs open. Without enough surfactant, the alveoli collapse, leading to difficulty in breathing and respiratory distress. COPD, anoxia, pulmonary embolism, and pneumothorax are all conditions that can cause breathing difficulties, but they are not specifically related to inadequate surfactant production and alveolar collapse. Therefore, the correct answer is respiratory distress syndrome.Rate this question:
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- 50.
Asthma is
- A.
A collapsed lung.
- B.
An acute condition resulting from unusually sensitive, irritated conducting airways.
- C.
An obstructive tumor.
- D.
Characterized by fluid buildup in the alveoli.
- E.
Caused by Mycobacterium tuberculosis.
Correct Answer
B. An acute condition resulting from unusually sensitive, irritated conducting airways.Explanation
Asthma is an acute condition resulting from unusually sensitive, irritated conducting airways. This means that when a person with asthma is exposed to certain triggers such as allergens or irritants, their airways become inflamed and narrow, making it difficult for air to pass through. This can lead to symptoms such as wheezing, shortness of breath, and coughing. It is not a collapsed lung, obstructive tumor, or caused by Mycobacterium tuberculosis. Additionally, it is not characterized by fluid buildup in the alveoli.Rate this question:
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.JPG "Use Figure 20-2 to answer the following questions:
What is the relationship between the pressures at label \"3")
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