1.
Boyle's law states that gas volume is
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.
2.
Pulmonary ventilation refers to the
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." This is because pulmonary ventilation specifically refers to the process of breathing, where air is drawn into the lungs (inspiration) and then expelled from the lungs (expiration). It does not refer to the movement of gases between different areas of the respiratory system or the utilization of oxygen.
3.
The function of pulmonary ventilation is to
Correct Answer
C. Maintain adequate alveolar ventilation.
Explanation
Pulmonary ventilation refers to the process of breathing, which involves the movement of air in and out of the lungs. The function of pulmonary ventilation is to maintain adequate alveolar ventilation. Alveolar ventilation refers to the amount of fresh air that reaches the alveoli (tiny air sacs in the lungs) where gas exchange occurs. It is important to maintain adequate alveolar ventilation to ensure that enough oxygen is supplied to the blood and carbon dioxide is efficiently removed from the body.
4.
The unit of measurement for pressure preferred by many respiratory therapists is
Correct Answer
B. Torr.
Explanation
The unit of measurement for pressure preferred by many respiratory therapists is torr. This is because torr is equivalent to millimeters of mercury (mm Hg), which is commonly used in medical settings to measure blood pressure. Additionally, torr is also equivalent to centimeters of water (cm H2O), which is used to measure pressure in respiratory therapy. Therefore, torr encompasses both mm Hg and cm H2O, making it the preferred unit of measurement for respiratory therapists.
5.
Which of the following is greater?
Correct Answer
A. The partial pressure of oxygen in atmospHeric air
Explanation
The partial pressure of oxygen in atmospheric air is greater than the partial pressure of oxygen in the alveoli because atmospheric air contains a higher concentration of oxygen compared to the air in the alveoli. Oxygen is constantly being exchanged between the lungs and the atmosphere during respiration, and as oxygen is inhaled, it mixes with other gases in the alveoli, causing its partial pressure to decrease.
6.
Boyle's Law of Gases states that
Correct Answer
E. If the volume goes up, the pressure goes down.
Explanation
According to Boyle's Law of Gases, if the volume of a gas increases, the pressure of the gas decreases. This is because there is an inverse relationship between the volume and pressure of a gas at constant temperature. When the volume increases, the gas molecules have more space to move around, resulting in fewer collisions with the container walls and a decrease in pressure. Conversely, if the volume decreases, the gas molecules are more confined, leading to more frequent collisions and an increase in pressure.
7.
Use Figure 20-2 to answer the following questions:
Which muscle(s) produce(s) the movement labeled "1"?
Correct Answer
C. External intercostals
Explanation
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 in question. By analyzing the image, it can be deduced that the movement labeled "1" is produced by the external intercostals.
8.
Use Figure 20-2 to answer the following questions:
What is the relationship between the pressures at label "3
Correct Answer
B. P outside > P inside
Explanation
Based on Figure 20-2, the pressure at label "3" outside the object is greater than the pressure inside the object.
9.
Use Figure 20-2 to answer the following questions:
What pressure will be present in the space labeled "5"?
Correct Answer
B. Intrapulmonary pressure
Explanation
Based on Figure 20-2, the space labeled "5" is within the lungs, specifically the alveoli. The pressure in this space is referred to as intrapulmonary pressure, which represents the pressure within the lungs during the respiratory cycle. Therefore, the correct answer is intrapulmonary pressure.
10.
Use Figure 20-2 to answer the following questions:
What is the relationship between the pressures at label "8"?
Correct Answer
C. P outside < P inside
Explanation
Based on Figure 20-2, the pressure at label "8" is lower outside compared to inside.
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"?
Correct Answer
E. Both rectus abdominis and internal intercostals
Explanation
The arrows labeled "6" and "7" indicate the movement of the ribcage during inhalation. The rectus abdominis and internal intercostals are the muscles responsible for this movement. The rectus abdominis contracts to pull the ribcage downward, while the internal intercostals contract to elevate the ribcage. Therefore, both muscles are involved in causing the movement indicated by the arrows.
12.
Air moves out of the lungs when the pressure inside the lungs is
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 higher pressure to an area of lower pressure. When the pressure inside the lungs is greater than the pressure in the atmosphere, it creates a pressure gradient that allows air to be expelled from the lungs and into the atmosphere.
13.
When there is no air movement, the relationship between the intrapulmonary and atmospheric pressure is that
Correct Answer
A. They are equal.
Explanation
When there is no air movement, the intrapulmonary pressure, which is the pressure inside the lungs, is equal to the atmospheric pressure, which is the pressure of the air outside the body. This means that there is no pressure difference between the lungs and the atmosphere, resulting in no air movement.
14.
Which of the following muscles might be recruited to increase inspired volume?
Correct Answer
E. All of the above
Explanation
All of the muscles mentioned, sternocleidomastoid, pectoralis minor, scalenes, and serratus anterior, can be recruited to increase inspired volume. These muscles are involved in the process of inhalation and play a role in expanding the thoracic cavity to allow for greater air intake. The sternocleidomastoid helps elevate the sternum and clavicles, the pectoralis minor lifts the ribs, the scalenes lift the upper ribs, and the serratus anterior helps expand the rib cage. Together, these muscles work synergistically to increase the volume of air inspired during inhalation.
15.
Expiratory movements are produced by contraction of the ________ muscle(s).
Correct Answer
C. Internal intercostal
Explanation
Expiratory movements are produced by contraction of the internal intercostal muscles. These muscles are located between the ribs and play a role in decreasing the size of the thoracic cavity during exhalation. When they contract, the internal intercostal muscles pull the ribs downward and inward, decreasing the volume of the chest cavity and forcing air out of the lungs. This contraction is essential for effective exhalation and is responsible for expelling carbon dioxide from the body.
16.
When the diaphragm and external intercostal muscles contract,
Correct Answer
A. The volume of the thorax increases.
Explanation
When the diaphragm and external intercostal muscles contract, the volume of the thorax increases. This is because the diaphragm, which is a dome-shaped muscle located at the base of the lungs, flattens and moves downward, while the external intercostal muscles between the ribs contract, causing the ribcage to move upward and outward. These movements create more space in the thoracic cavity, allowing the lungs to expand and fill with air. As a result, the volume of the thorax increases.
17.
Which of these descriptions best matches the term external intercostal?
Correct Answer
C. Primary muscle of inspiration
Explanation
The external intercostal muscles are the primary muscles of inspiration. During inhalation, these muscles contract to lift and expand the ribcage, allowing for the expansion of the lungs and the intake of air. They play a crucial role in the process of breathing by aiding in the expansion of the thoracic cavity and facilitating inhalation.
18.
________ is the amount of air that moves into the respiratory system during a single respiratory cycle under resting conditions.
Correct Answer
D. Tidal volume
Explanation
Tidal volume is 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. It is different from other respiratory volumes such as residual volume, expiratory reserve volume, inspiratory reserve volume, and inspiratory capacity, which all refer to different aspects of lung capacity and function.
19.
________ is the amount of air that you can inhale above the resting tidal volume.
Correct Answer
C. Inspiratory reserve volume
Explanation
The inspiratory reserve volume refers to the amount of air that can be inhaled above the resting tidal volume. It represents the maximum amount of air that can be inhaled forcefully after a normal inhalation. This volume is important for activities that require increased oxygen intake, such as exercise or physical exertion.
20.
In quiet breathing,
Correct Answer
C. Inspiration involves muscular contractions and expiration is passive.
Explanation
In quiet breathing, inspiration involves muscular contractions and expiration is passive. During inspiration, the diaphragm and intercostal muscles contract to expand the chest cavity, allowing air to enter the lungs. This is an active process that requires muscular effort. On the other hand, expiration in quiet breathing is a passive process that does not require muscular contractions. The relaxation of the diaphragm and intercostal muscles causes the chest cavity to decrease in size, pushing air out of the lungs.
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
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. Vital capacity is the maximum amount of air that can be exhaled after a maximum inhalation and is an important measure of lung function. It represents the total volume of air that the patient can move in and out of their lungs and is used to assess respiratory health and diagnose respiratory conditions.
22.
Alveolar ventilation refers to the
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 is the correct answer because alveolar ventilation specifically refers to the movement of air into and out of the lungs, and more specifically, the amount of air that reaches the alveoli, which are the tiny air sacs in the lungs where gas exchange occurs. This is an important measure of lung function and is necessary for the exchange of oxygen and carbon dioxide between the lungs and the bloodstream.
23.
Increasing the alveolar ventilation rate will
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 is brought into and out of 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 its partial pressure. As a result, there will be a decrease in the partial pressure of carbon dioxide in the alveoli.
24.
________ equals the respiratory rate × (tidal volume - anatomic dead space).
Correct Answer
D. Alveolar ventilation rate
Explanation
Alveolar ventilation rate is the correct answer because it is calculated by multiplying the respiratory rate by the difference between tidal volume and anatomic dead space. Alveolar ventilation rate represents the volume of fresh air that reaches the alveoli per minute, which is important for efficient gas exchange in the lungs. Vital capacity refers to the maximum amount of air that can be exhaled after a maximum inhalation. Respiratory minute volume is the total volume of air inhaled and exhaled per minute. Pulmonary ventilation rate is the total volume of air moved in and out of the lungs per minute. External respiration rate is not a recognized term in respiratory physiology.
25.
Which of the following can be calculated if the tidal volume and respiratory rate are known?
Correct Answer
A. Respiratory minute volume
Explanation
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 moved in and out of the lungs in one minute. It is calculated by multiplying the tidal volume (the amount of air moved in and out of the lungs in one breath) by the respiratory rate (the number of breaths taken per minute). Therefore, knowing the tidal volume and respiratory rate allows for the calculation of the respiratory minute volume.
26.
Henry's law states that
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 of the gas will dissolve. This relationship is important in various fields such as chemistry and environmental science, where the solubility of gases in liquids plays a crucial role in many processes.
27.
Dalton's law states that
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 the pressure exerted by each gas in the mixture is independent of the pressure exerted by the other gases present. The total pressure is simply the sum of these individual pressures. This law is important in understanding the behavior of gases in mixtures and is used in various applications, such as determining the composition of gases in the atmosphere.
28.
The partial pressure of oxygen in arterial blood is approximately
Correct Answer
E. 95 mm Hg.
Explanation
The correct answer is 95 mm Hg. This is because the partial pressure of oxygen in arterial blood is higher compared to other locations in the body. Arterial blood carries oxygen from the lungs to the rest of the body, so it has a higher concentration of oxygen. A normal value for the partial pressure of oxygen in arterial blood is around 95 mm Hg.
29.
The partial pressure of carbon dioxide in venous blood is approximately
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 produced as a waste product. This carbon dioxide then diffuses from the tissues into the venous blood, resulting in an increase in its partial pressure. The normal range for the partial pressure of carbon dioxide in venous blood is around 35-45 mm Hg, with 45 mm Hg being a commonly accepted value.
30.
The partial pressure of oxygen in the interstitial space of peripheral tissues is approximately
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 is delivered to the tissues through the bloodstream, and as it diffuses from the capillaries into the interstitial space, its partial pressure decreases. The normal partial pressure of oxygen in arterial blood is around 100 mm Hg, and as it reaches the tissues, it is utilized by cells for metabolism, resulting in a decrease in partial pressure to around 40 mm Hg.
31.
The partial pressure of carbon dioxide in the interstitial space of peripheral tissues is approximately
Correct Answer
B. 45 mm Hg.
Explanation
The partial pressure of carbon dioxide in the interstitial space of peripheral tissues is approximately 45 mm Hg. This is because carbon dioxide is continuously produced as a waste product of cellular respiration and diffuses out of the cells into the interstitial fluid. From there, it enters the capillaries where it is carried back to the lungs for elimination. The partial pressure of carbon dioxide in the interstitial space is lower than in the cells due to its diffusion out of the cells, but higher than in the capillaries. 45 mm Hg is within the normal range for carbon dioxide partial pressure in the interstitial space.
32.
The process by which dissolved gases are exchanged between the blood and interstitial fluids is
Correct Answer
C. Internal respiration.
Explanation
Internal respiration refers to the exchange of gases (oxygen and carbon dioxide) between the blood and the cells of the body. It occurs in the capillaries, where oxygen from the blood diffuses into the cells, and carbon dioxide produced by the cells diffuses into the blood to be transported back to the lungs for elimination. Pulmonary ventilation is the process of breathing, external respiration is the exchange of gases between the lungs and the blood, and cellular respiration is the process by which cells generate energy from oxygen and glucose. Therefore, the correct answer is internal respiration.
33.
Which of the following is greatest?
Correct Answer
A. The partial pressure of carbon dioxide in venous blood
Explanation
The partial pressure of carbon dioxide in venous blood is the greatest because it represents the amount of carbon dioxide that has been produced as a waste product by the body's cells and is being transported back to the lungs to be exhaled. The other options represent the partial pressure of carbon dioxide in different parts of the respiratory system, but the highest concentration is found in venous blood.
34.
Each of the following factors affects the rate of external respiration, except the
Correct Answer
D. Diameter of an alveolus.
Explanation
The rate of external respiration is influenced by several factors, including the PO2 of the alveoli, PCO2 of the blood, thickness of the respiratory membrane, and solubility of oxygen in plasma. However, the diameter of an alveolus does not directly impact the rate of external respiration. The diameter of an alveolus refers to its size, and while it may affect other aspects of lung function, it does not play a significant role in the rate at which oxygen is exchanged between the alveoli and the blood.
35.
External respiration involves the
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. It involves the diffusion of gases, specifically oxygen and carbon dioxide, between the alveoli (tiny air sacs in the lungs) and the circulating blood. Oxygen from the alveoli diffuses into the blood, while carbon dioxide from the blood diffuses into the alveoli to be exhaled. This exchange of gases is crucial for maintaining the body's oxygen supply and removing waste carbon dioxide.
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
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, meaning that it can dissolve more easily in water. Therefore, 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 create a more favorable environment for oxygen to dissolve in plasma, balancing the solubility of both gases.
37.
At a PO2 of 70 mm Hg and normal temperature and pH, hemoglobin is ________ percent saturated with oxygen.
Correct Answer
E. More than 90
Explanation
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 available binding sites on hemoglobin molecules are occupied by oxygen molecules.
38.
Most of the oxygen transported by the blood is
Correct Answer
B. Bound to hemoglobin.
Explanation
Oxygen is primarily transported in the blood by binding to hemoglobin molecules in red blood cells. Hemoglobin has a high affinity for oxygen, allowing it to bind to oxygen in the lungs and release it to tissues throughout the body. This mechanism ensures efficient oxygen delivery to cells and tissues.
39.
Each 100 ml of blood leaving the alveolar capillaries carries away roughly ________ ml of oxygen.
Correct Answer
B. 20
Explanation
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. Oxygen from the inhaled air diffuses into the capillaries and binds to hemoglobin in red blood cells, which then transports it to the rest of the body. The average oxygen saturation of arterial blood is around 95-100%, meaning that each 100 ml of blood leaving the alveolar capillaries carries approximately 20 ml of oxygen.
40.
Under quiet conditions, blood returning to the heart retains about ________ of its oxygen content when it leaves the lungs.
Correct Answer
C. 75 percent
Explanation
Under quiet conditions, blood returning to the heart retains about 75 percent of its oxygen content when it leaves the lungs. This means that 25 percent of the oxygen is used up by the body's tissues and organs before the blood returns to the heart. This is a normal physiological process as the body requires oxygen for energy production and other vital functions.
41.
Which of the following would be greater?
Correct Answer
A. The percent of oxygen saturation of hemoglobin when the pH is 7.6
Explanation
The percent of oxygen saturation of hemoglobin is greater when the pH is 7.6 compared to when the pH is 7.2. This is because a higher pH indicates a more alkaline environment, which promotes the release of oxygen from hemoglobin and increases its saturation. Conversely, a lower pH (more acidic environment) decreases the oxygen saturation of hemoglobin. Therefore, the percent of oxygen saturation is higher at a pH of 7.6 than at a pH of 7.2.
42.
Which of the following would be greater?
Correct Answer
B. Hemoglobin's affinity for oxygen when the BPG level is low
Explanation
When the BPG (bisphosphoglycerate) level is high, it binds to hemoglobin and decreases its affinity for oxygen. This means that hemoglobin is less likely to bind to oxygen molecules, resulting in a lower affinity for oxygen. On the other hand, when the BPG level is low, there is less binding to hemoglobin, allowing it to have a higher affinity for oxygen. Therefore, hemoglobin's affinity for oxygen is greater when the BPG level is low.
43.
Low pH alters hemoglobin structure so that oxygen binds less strongly to hemoglobin at low PO2. This increases the effectiveness of
Correct Answer
B. Internal respiration.
Explanation
Low pH alters hemoglobin structure, causing oxygen to bind less strongly to hemoglobin at low PO2. This change in hemoglobin structure allows oxygen to be released more easily to the tissues during internal respiration. Internal respiration refers to the exchange of gases between the blood and the body's tissues, where oxygen is delivered to the cells and carbon dioxide is removed. Therefore, the increased effectiveness of internal respiration is the most appropriate explanation for the given scenario.
44.
Which of the following factors would increase the amount of oxygen discharged by hemoglobin to peripheral tissues?
Correct Answer
B. Decreased pH
Explanation
A decreased pH would increase the amount of oxygen discharged by hemoglobin to peripheral tissues because it causes a shift in the oxygen-hemoglobin dissociation curve to the right. This means that hemoglobin has a lower affinity for oxygen, making it easier for oxygen to be released to the tissues.
45.
For maximum loading of hemoglobin with oxygen at the lungs, the
Correct Answer
E. PCO2 should be low.
Explanation
In order to maximize the loading of hemoglobin with oxygen at the lungs, the PCO2 should be low. This is because a low PCO2 indicates that there is a low concentration of carbon dioxide in the blood, which allows for more oxygen to bind to hemoglobin. When the PCO2 is high, it indicates that there is a high concentration of carbon dioxide, which can compete with oxygen for binding sites on hemoglobin and reduce the amount of oxygen that can be carried. Therefore, a low PCO2 is necessary for maximum loading of hemoglobin with oxygen.
46.
Most of the carbon dioxide in the blood is transported as
Correct Answer
C. Bicarbonate ions.
Explanation
Carbon dioxide is transported in the blood in three forms: dissolved in plasma, bound to hemoglobin as carbaminohemoglobin, and as bicarbonate ions. However, the majority of carbon dioxide is transported as bicarbonate ions. When carbon dioxide enters the red blood cells, it combines with water to form carbonic acid, which quickly dissociates into bicarbonate ions and hydrogen ions. The bicarbonate ions are then transported out of the red blood cells into the plasma, where they can be carried to the lungs and exhaled. This process helps to maintain the acid-base balance in the body.
47.
Carbonic anhydrase
Correct Answer
E. All of the above
Explanation
Carbonic anhydrase is an enzyme found in red blood cells that plays a crucial role in regulating the levels of bicarbonate ion in plasma. It achieves this by converting carbon dioxide into carbonic acid. Therefore, the correct answer is "all of the above" as it encompasses all the given statements about carbonic anhydrase.
48.
Which statement about the chloride shift is false?
Correct Answer
E. Causes RBCs to swell
Explanation
The chloride shift is a process that involves the movement of chloride ions into red blood cells (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. However, it does not cause RBCs to swell. Therefore, the statement "causes RBCs to swell" is false.
49.
The condition resulting from inadequate production of surfactant and the resultant collapse of alveoli is
Correct Answer
A. Respiratory distress syndrome.
Explanation
The condition resulting from inadequate production of surfactant and the resultant collapse of alveoli is respiratory distress syndrome. This syndrome occurs primarily in premature infants and can also affect adults with certain risk factors. The inadequate production of surfactant leads to the collapse of alveoli, causing difficulty in breathing and insufficient oxygen exchange. COPD, anoxia, pulmonary embolism, and pneumothorax are all different conditions that can also cause respiratory distress, but they are not specifically related to inadequate surfactant production and alveolar collapse.
50.
Asthma is
Correct Answer
B. An acute condition resulting from unusually sensitive, irritated conducting airways.
Explanation
The correct answer is an acute condition resulting from unusually sensitive, irritated conducting airways. Asthma is a chronic respiratory condition characterized by inflammation and narrowing of the airways, which leads to symptoms such as wheezing, coughing, and shortness of breath. These symptoms are triggered by various factors, such as allergens, exercise, or respiratory infections, and result from the hypersensitivity and irritability of the airways. This explanation aligns with the understanding of asthma as a condition that involves the hyperreactivity of the conducting airways rather than a collapsed lung, obstructive tumor, fluid buildup in the alveoli, or infection with Mycobacterium tuberculosis.