Other Respiratory Physiology - MCAT Biological and Biochemical Foundations of Living Systems
Card 1 of 48
The carbonic anhydrase reaction is shown below.
Which of the following outcomes seems the most reasonable for someone who has an increase in blood CO2 levels during exercise?
The carbonic anhydrase reaction is shown below.
Which of the following outcomes seems the most reasonable for someone who has an increase in blood CO2 levels during exercise?
Tap to reveal answer
The individual's blood pH level will decrease (become more acidic). The increase in CO2 will cause the carbonic anhydrase reaction to shift to the right, increasing the concentration of protons (H+) in the blood. The individual can raise their pH level back to normal by breathing out all of the excess CO2. This accounts, in part, for increased respiration rates during exercise (along with the increased demand for oxygen).
The individual's blood pH level will decrease (become more acidic). The increase in CO2 will cause the carbonic anhydrase reaction to shift to the right, increasing the concentration of protons (H+) in the blood. The individual can raise their pH level back to normal by breathing out all of the excess CO2. This accounts, in part, for increased respiration rates during exercise (along with the increased demand for oxygen).
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Whales are active at great, underwater depths for extended periods of time. Which of the following would LEAST contribute to such an ability?
Whales are active at great, underwater depths for extended periods of time. Which of the following would LEAST contribute to such an ability?
Tap to reveal answer
When whales dive to great depths, they are unable to replenish oxygen from the water's surface. Several adaptive characteristics allow for the whales to maintain adequate oxygen supply to their tissues: large lung capacity (to absorb a greater amount of oxygen when breathing), selective arterial constriction (to restrict blood flow to non-essential tissues and thus prevent inefficient oxygen consumption), high cellular tolerance for carbon dioxide (CO₂ will build up over time without gas exchange), and large muscle myoglobin concentrations (to replenish oxygen supply to muscles as necessary).
A high basal metabolic rate, however, would increase the demand for oxygen and thus would not be an adaptive characteristic for whales in order to maintain themselves at great, watery depths without an external supply of oxygen.
When whales dive to great depths, they are unable to replenish oxygen from the water's surface. Several adaptive characteristics allow for the whales to maintain adequate oxygen supply to their tissues: large lung capacity (to absorb a greater amount of oxygen when breathing), selective arterial constriction (to restrict blood flow to non-essential tissues and thus prevent inefficient oxygen consumption), high cellular tolerance for carbon dioxide (CO₂ will build up over time without gas exchange), and large muscle myoglobin concentrations (to replenish oxygen supply to muscles as necessary).
A high basal metabolic rate, however, would increase the demand for oxygen and thus would not be an adaptive characteristic for whales in order to maintain themselves at great, watery depths without an external supply of oxygen.
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Which of the following is a physiological consequence of breathing air with a slightly increased partial pressure of carbon dioxide?
Which of the following is a physiological consequence of breathing air with a slightly increased partial pressure of carbon dioxide?
Tap to reveal answer
Slightly increased levels, or partial pressures, of carbon dioxide (CO2) would signal for an increase in breathing rate. As CO2 levels in the blood rise due to the breathing of such air as described in the passage, a breathing mechanism in the brain is triggered to increase ventilation (hyperventilation) to remove as much CO2 through the lungs as possible. A decrease in breathing rate would build up CO2 to even higher levels, causing respiratory acidosis. There would be no changes to blood pressure because slight increases of CO2 has no significant effect on this property.
Slightly increased levels, or partial pressures, of carbon dioxide (CO2) would signal for an increase in breathing rate. As CO2 levels in the blood rise due to the breathing of such air as described in the passage, a breathing mechanism in the brain is triggered to increase ventilation (hyperventilation) to remove as much CO2 through the lungs as possible. A decrease in breathing rate would build up CO2 to even higher levels, causing respiratory acidosis. There would be no changes to blood pressure because slight increases of CO2 has no significant effect on this property.
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Where in the brain is respiration rate regulated?
Where in the brain is respiration rate regulated?
Tap to reveal answer
It is important to know that the medulla oblongata in the brainstem is the site of breathing rate control. pH receptors at the medulla sense the hydrogen concentration in the blood, and increase or decrease the rate of breathing to alter bicarbonate levels in the blood, maintaining healthy pH levels.
The cerebellum is involved in balance and coordination, while the frontal cortex and occipital lobe are both regions of the cerebrum, involved in higher thinking, processing, and voluntary actions.
It is important to know that the medulla oblongata in the brainstem is the site of breathing rate control. pH receptors at the medulla sense the hydrogen concentration in the blood, and increase or decrease the rate of breathing to alter bicarbonate levels in the blood, maintaining healthy pH levels.
The cerebellum is involved in balance and coordination, while the frontal cortex and occipital lobe are both regions of the cerebrum, involved in higher thinking, processing, and voluntary actions.
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Give the equation for total lung capacity.
Give the equation for total lung capacity.
Tap to reveal answer
The total lung capacity is the maximum amount of air that can fill the lungs.
The vital capacity is the amount of air that can be exhaled after fully inhaling.
The tidal volume is the amount of air inhaled during normal, relaxed breathing.
The expiratory reserve volume is the amount of air that can be forcibly exhaled after a normal exhalation.
The inspiratory reserve volume is the amount of air that can be forcibly inhaled after a normal inhalation.
The residual volume is the amount of air still remaining in the lungs after the expiratory reserve volume is exhaled.
By adding the residual volume and vital capacity, you can obtain a value for the total lung capacity.
The total lung capacity is the maximum amount of air that can fill the lungs.
The vital capacity is the amount of air that can be exhaled after fully inhaling.
The tidal volume is the amount of air inhaled during normal, relaxed breathing.
The expiratory reserve volume is the amount of air that can be forcibly exhaled after a normal exhalation.
The inspiratory reserve volume is the amount of air that can be forcibly inhaled after a normal inhalation.
The residual volume is the amount of air still remaining in the lungs after the expiratory reserve volume is exhaled.
By adding the residual volume and vital capacity, you can obtain a value for the total lung capacity.
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Both the sympathetic and the parasympathetic nervous systems are essential for homeostasis and for survival. For example, when we are trying to run away from a threat, the sympathetic nervous system is in full effect to allow us to escape from danger. However, when there is no obvious threat, the parasympathetic nervous system tends to be more in control.
There are similarities and differences between the sympathetic and the parasympathetic nervous systems. In preganglionic nerve fibers, both the sympathetic and the parasympathetic nervous system utilize the neurotransmitter acetylcholine. Closer to the target organ, the parasympathetic nervous system remains dependent on acetylcholine whereas norepinephrine and epinephrine are the predominant neurotransmitters utilized by the sympathetic nervous system.
When norepinephrine and epinephrine bind to their receptors, different effects are carried out based on the type of receptor, affinity, and location of the receptor. For example, epinephrine has a higher affinity for the beta-2 receptor. When epinephrine binds to the beta-2 receptor, common effects include vasodilation and bronchodilation. Norepinephrine has a stronger affinity for the alpha-1, alpha-2 and beta-1 receptors. When norepinephrine binds to its receptor, common effects on the body include vasoconstriction (alpha-1), increased heart rate (beta-1) and uterine contraction (alpha-1).
When a patient has a severe allergic reaction, a common prescribed drug is epinephrine. Which of the follow best explains the effects of epinephrine on a patient experiencing a severe allergic reaction?
Both the sympathetic and the parasympathetic nervous systems are essential for homeostasis and for survival. For example, when we are trying to run away from a threat, the sympathetic nervous system is in full effect to allow us to escape from danger. However, when there is no obvious threat, the parasympathetic nervous system tends to be more in control.
There are similarities and differences between the sympathetic and the parasympathetic nervous systems. In preganglionic nerve fibers, both the sympathetic and the parasympathetic nervous system utilize the neurotransmitter acetylcholine. Closer to the target organ, the parasympathetic nervous system remains dependent on acetylcholine whereas norepinephrine and epinephrine are the predominant neurotransmitters utilized by the sympathetic nervous system.
When norepinephrine and epinephrine bind to their receptors, different effects are carried out based on the type of receptor, affinity, and location of the receptor. For example, epinephrine has a higher affinity for the beta-2 receptor. When epinephrine binds to the beta-2 receptor, common effects include vasodilation and bronchodilation. Norepinephrine has a stronger affinity for the alpha-1, alpha-2 and beta-1 receptors. When norepinephrine binds to its receptor, common effects on the body include vasoconstriction (alpha-1), increased heart rate (beta-1) and uterine contraction (alpha-1).
When a patient has a severe allergic reaction, a common prescribed drug is epinephrine. Which of the follow best explains the effects of epinephrine on a patient experiencing a severe allergic reaction?
Tap to reveal answer
Epinephrine binds to the beta-2 receptor. The binding of epinephrine to the beta-2 receptor causes bronchodilation by relaxing the smooth muscles surrounding the airway. The relaxation of the smooth muscles around the airway increases the airway diameter and therefore allows the patient to breathe easier.
Epinephrine binds to the beta-2 receptor. The binding of epinephrine to the beta-2 receptor causes bronchodilation by relaxing the smooth muscles surrounding the airway. The relaxation of the smooth muscles around the airway increases the airway diameter and therefore allows the patient to breathe easier.
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The carbonic anhydrase reaction is shown below.
Which of the following outcomes seems the most reasonable for someone who has an increase in blood CO2 levels during exercise?
The carbonic anhydrase reaction is shown below.
Which of the following outcomes seems the most reasonable for someone who has an increase in blood CO2 levels during exercise?
Tap to reveal answer
The individual's blood pH level will decrease (become more acidic). The increase in CO2 will cause the carbonic anhydrase reaction to shift to the right, increasing the concentration of protons (H+) in the blood. The individual can raise their pH level back to normal by breathing out all of the excess CO2. This accounts, in part, for increased respiration rates during exercise (along with the increased demand for oxygen).
The individual's blood pH level will decrease (become more acidic). The increase in CO2 will cause the carbonic anhydrase reaction to shift to the right, increasing the concentration of protons (H+) in the blood. The individual can raise their pH level back to normal by breathing out all of the excess CO2. This accounts, in part, for increased respiration rates during exercise (along with the increased demand for oxygen).
← Didn't Know|Knew It →
Whales are active at great, underwater depths for extended periods of time. Which of the following would LEAST contribute to such an ability?
Whales are active at great, underwater depths for extended periods of time. Which of the following would LEAST contribute to such an ability?
Tap to reveal answer
When whales dive to great depths, they are unable to replenish oxygen from the water's surface. Several adaptive characteristics allow for the whales to maintain adequate oxygen supply to their tissues: large lung capacity (to absorb a greater amount of oxygen when breathing), selective arterial constriction (to restrict blood flow to non-essential tissues and thus prevent inefficient oxygen consumption), high cellular tolerance for carbon dioxide (CO₂ will build up over time without gas exchange), and large muscle myoglobin concentrations (to replenish oxygen supply to muscles as necessary).
A high basal metabolic rate, however, would increase the demand for oxygen and thus would not be an adaptive characteristic for whales in order to maintain themselves at great, watery depths without an external supply of oxygen.
When whales dive to great depths, they are unable to replenish oxygen from the water's surface. Several adaptive characteristics allow for the whales to maintain adequate oxygen supply to their tissues: large lung capacity (to absorb a greater amount of oxygen when breathing), selective arterial constriction (to restrict blood flow to non-essential tissues and thus prevent inefficient oxygen consumption), high cellular tolerance for carbon dioxide (CO₂ will build up over time without gas exchange), and large muscle myoglobin concentrations (to replenish oxygen supply to muscles as necessary).
A high basal metabolic rate, however, would increase the demand for oxygen and thus would not be an adaptive characteristic for whales in order to maintain themselves at great, watery depths without an external supply of oxygen.
← Didn't Know|Knew It →
Which of the following is a physiological consequence of breathing air with a slightly increased partial pressure of carbon dioxide?
Which of the following is a physiological consequence of breathing air with a slightly increased partial pressure of carbon dioxide?
Tap to reveal answer
Slightly increased levels, or partial pressures, of carbon dioxide (CO2) would signal for an increase in breathing rate. As CO2 levels in the blood rise due to the breathing of such air as described in the passage, a breathing mechanism in the brain is triggered to increase ventilation (hyperventilation) to remove as much CO2 through the lungs as possible. A decrease in breathing rate would build up CO2 to even higher levels, causing respiratory acidosis. There would be no changes to blood pressure because slight increases of CO2 has no significant effect on this property.
Slightly increased levels, or partial pressures, of carbon dioxide (CO2) would signal for an increase in breathing rate. As CO2 levels in the blood rise due to the breathing of such air as described in the passage, a breathing mechanism in the brain is triggered to increase ventilation (hyperventilation) to remove as much CO2 through the lungs as possible. A decrease in breathing rate would build up CO2 to even higher levels, causing respiratory acidosis. There would be no changes to blood pressure because slight increases of CO2 has no significant effect on this property.
← Didn't Know|Knew It →
Where in the brain is respiration rate regulated?
Where in the brain is respiration rate regulated?
Tap to reveal answer
It is important to know that the medulla oblongata in the brainstem is the site of breathing rate control. pH receptors at the medulla sense the hydrogen concentration in the blood, and increase or decrease the rate of breathing to alter bicarbonate levels in the blood, maintaining healthy pH levels.
The cerebellum is involved in balance and coordination, while the frontal cortex and occipital lobe are both regions of the cerebrum, involved in higher thinking, processing, and voluntary actions.
It is important to know that the medulla oblongata in the brainstem is the site of breathing rate control. pH receptors at the medulla sense the hydrogen concentration in the blood, and increase or decrease the rate of breathing to alter bicarbonate levels in the blood, maintaining healthy pH levels.
The cerebellum is involved in balance and coordination, while the frontal cortex and occipital lobe are both regions of the cerebrum, involved in higher thinking, processing, and voluntary actions.
← Didn't Know|Knew It →
Give the equation for total lung capacity.
Give the equation for total lung capacity.
Tap to reveal answer
The total lung capacity is the maximum amount of air that can fill the lungs.
The vital capacity is the amount of air that can be exhaled after fully inhaling.
The tidal volume is the amount of air inhaled during normal, relaxed breathing.
The expiratory reserve volume is the amount of air that can be forcibly exhaled after a normal exhalation.
The inspiratory reserve volume is the amount of air that can be forcibly inhaled after a normal inhalation.
The residual volume is the amount of air still remaining in the lungs after the expiratory reserve volume is exhaled.
By adding the residual volume and vital capacity, you can obtain a value for the total lung capacity.
The total lung capacity is the maximum amount of air that can fill the lungs.
The vital capacity is the amount of air that can be exhaled after fully inhaling.
The tidal volume is the amount of air inhaled during normal, relaxed breathing.
The expiratory reserve volume is the amount of air that can be forcibly exhaled after a normal exhalation.
The inspiratory reserve volume is the amount of air that can be forcibly inhaled after a normal inhalation.
The residual volume is the amount of air still remaining in the lungs after the expiratory reserve volume is exhaled.
By adding the residual volume and vital capacity, you can obtain a value for the total lung capacity.
← Didn't Know|Knew It →
Both the sympathetic and the parasympathetic nervous systems are essential for homeostasis and for survival. For example, when we are trying to run away from a threat, the sympathetic nervous system is in full effect to allow us to escape from danger. However, when there is no obvious threat, the parasympathetic nervous system tends to be more in control.
There are similarities and differences between the sympathetic and the parasympathetic nervous systems. In preganglionic nerve fibers, both the sympathetic and the parasympathetic nervous system utilize the neurotransmitter acetylcholine. Closer to the target organ, the parasympathetic nervous system remains dependent on acetylcholine whereas norepinephrine and epinephrine are the predominant neurotransmitters utilized by the sympathetic nervous system.
When norepinephrine and epinephrine bind to their receptors, different effects are carried out based on the type of receptor, affinity, and location of the receptor. For example, epinephrine has a higher affinity for the beta-2 receptor. When epinephrine binds to the beta-2 receptor, common effects include vasodilation and bronchodilation. Norepinephrine has a stronger affinity for the alpha-1, alpha-2 and beta-1 receptors. When norepinephrine binds to its receptor, common effects on the body include vasoconstriction (alpha-1), increased heart rate (beta-1) and uterine contraction (alpha-1).
When a patient has a severe allergic reaction, a common prescribed drug is epinephrine. Which of the follow best explains the effects of epinephrine on a patient experiencing a severe allergic reaction?
Both the sympathetic and the parasympathetic nervous systems are essential for homeostasis and for survival. For example, when we are trying to run away from a threat, the sympathetic nervous system is in full effect to allow us to escape from danger. However, when there is no obvious threat, the parasympathetic nervous system tends to be more in control.
There are similarities and differences between the sympathetic and the parasympathetic nervous systems. In preganglionic nerve fibers, both the sympathetic and the parasympathetic nervous system utilize the neurotransmitter acetylcholine. Closer to the target organ, the parasympathetic nervous system remains dependent on acetylcholine whereas norepinephrine and epinephrine are the predominant neurotransmitters utilized by the sympathetic nervous system.
When norepinephrine and epinephrine bind to their receptors, different effects are carried out based on the type of receptor, affinity, and location of the receptor. For example, epinephrine has a higher affinity for the beta-2 receptor. When epinephrine binds to the beta-2 receptor, common effects include vasodilation and bronchodilation. Norepinephrine has a stronger affinity for the alpha-1, alpha-2 and beta-1 receptors. When norepinephrine binds to its receptor, common effects on the body include vasoconstriction (alpha-1), increased heart rate (beta-1) and uterine contraction (alpha-1).
When a patient has a severe allergic reaction, a common prescribed drug is epinephrine. Which of the follow best explains the effects of epinephrine on a patient experiencing a severe allergic reaction?
Tap to reveal answer
Epinephrine binds to the beta-2 receptor. The binding of epinephrine to the beta-2 receptor causes bronchodilation by relaxing the smooth muscles surrounding the airway. The relaxation of the smooth muscles around the airway increases the airway diameter and therefore allows the patient to breathe easier.
Epinephrine binds to the beta-2 receptor. The binding of epinephrine to the beta-2 receptor causes bronchodilation by relaxing the smooth muscles surrounding the airway. The relaxation of the smooth muscles around the airway increases the airway diameter and therefore allows the patient to breathe easier.
← Didn't Know|Knew It →
The carbonic anhydrase reaction is shown below.
Which of the following outcomes seems the most reasonable for someone who has an increase in blood CO2 levels during exercise?
The carbonic anhydrase reaction is shown below.
Which of the following outcomes seems the most reasonable for someone who has an increase in blood CO2 levels during exercise?
Tap to reveal answer
The individual's blood pH level will decrease (become more acidic). The increase in CO2 will cause the carbonic anhydrase reaction to shift to the right, increasing the concentration of protons (H+) in the blood. The individual can raise their pH level back to normal by breathing out all of the excess CO2. This accounts, in part, for increased respiration rates during exercise (along with the increased demand for oxygen).
The individual's blood pH level will decrease (become more acidic). The increase in CO2 will cause the carbonic anhydrase reaction to shift to the right, increasing the concentration of protons (H+) in the blood. The individual can raise their pH level back to normal by breathing out all of the excess CO2. This accounts, in part, for increased respiration rates during exercise (along with the increased demand for oxygen).
← Didn't Know|Knew It →
Whales are active at great, underwater depths for extended periods of time. Which of the following would LEAST contribute to such an ability?
Whales are active at great, underwater depths for extended periods of time. Which of the following would LEAST contribute to such an ability?
Tap to reveal answer
When whales dive to great depths, they are unable to replenish oxygen from the water's surface. Several adaptive characteristics allow for the whales to maintain adequate oxygen supply to their tissues: large lung capacity (to absorb a greater amount of oxygen when breathing), selective arterial constriction (to restrict blood flow to non-essential tissues and thus prevent inefficient oxygen consumption), high cellular tolerance for carbon dioxide (CO₂ will build up over time without gas exchange), and large muscle myoglobin concentrations (to replenish oxygen supply to muscles as necessary).
A high basal metabolic rate, however, would increase the demand for oxygen and thus would not be an adaptive characteristic for whales in order to maintain themselves at great, watery depths without an external supply of oxygen.
When whales dive to great depths, they are unable to replenish oxygen from the water's surface. Several adaptive characteristics allow for the whales to maintain adequate oxygen supply to their tissues: large lung capacity (to absorb a greater amount of oxygen when breathing), selective arterial constriction (to restrict blood flow to non-essential tissues and thus prevent inefficient oxygen consumption), high cellular tolerance for carbon dioxide (CO₂ will build up over time without gas exchange), and large muscle myoglobin concentrations (to replenish oxygen supply to muscles as necessary).
A high basal metabolic rate, however, would increase the demand for oxygen and thus would not be an adaptive characteristic for whales in order to maintain themselves at great, watery depths without an external supply of oxygen.
← Didn't Know|Knew It →
Which of the following is a physiological consequence of breathing air with a slightly increased partial pressure of carbon dioxide?
Which of the following is a physiological consequence of breathing air with a slightly increased partial pressure of carbon dioxide?
Tap to reveal answer
Slightly increased levels, or partial pressures, of carbon dioxide (CO2) would signal for an increase in breathing rate. As CO2 levels in the blood rise due to the breathing of such air as described in the passage, a breathing mechanism in the brain is triggered to increase ventilation (hyperventilation) to remove as much CO2 through the lungs as possible. A decrease in breathing rate would build up CO2 to even higher levels, causing respiratory acidosis. There would be no changes to blood pressure because slight increases of CO2 has no significant effect on this property.
Slightly increased levels, or partial pressures, of carbon dioxide (CO2) would signal for an increase in breathing rate. As CO2 levels in the blood rise due to the breathing of such air as described in the passage, a breathing mechanism in the brain is triggered to increase ventilation (hyperventilation) to remove as much CO2 through the lungs as possible. A decrease in breathing rate would build up CO2 to even higher levels, causing respiratory acidosis. There would be no changes to blood pressure because slight increases of CO2 has no significant effect on this property.
← Didn't Know|Knew It →
Where in the brain is respiration rate regulated?
Where in the brain is respiration rate regulated?
Tap to reveal answer
It is important to know that the medulla oblongata in the brainstem is the site of breathing rate control. pH receptors at the medulla sense the hydrogen concentration in the blood, and increase or decrease the rate of breathing to alter bicarbonate levels in the blood, maintaining healthy pH levels.
The cerebellum is involved in balance and coordination, while the frontal cortex and occipital lobe are both regions of the cerebrum, involved in higher thinking, processing, and voluntary actions.
It is important to know that the medulla oblongata in the brainstem is the site of breathing rate control. pH receptors at the medulla sense the hydrogen concentration in the blood, and increase or decrease the rate of breathing to alter bicarbonate levels in the blood, maintaining healthy pH levels.
The cerebellum is involved in balance and coordination, while the frontal cortex and occipital lobe are both regions of the cerebrum, involved in higher thinking, processing, and voluntary actions.
← Didn't Know|Knew It →
Give the equation for total lung capacity.
Give the equation for total lung capacity.
Tap to reveal answer
The total lung capacity is the maximum amount of air that can fill the lungs.
The vital capacity is the amount of air that can be exhaled after fully inhaling.
The tidal volume is the amount of air inhaled during normal, relaxed breathing.
The expiratory reserve volume is the amount of air that can be forcibly exhaled after a normal exhalation.
The inspiratory reserve volume is the amount of air that can be forcibly inhaled after a normal inhalation.
The residual volume is the amount of air still remaining in the lungs after the expiratory reserve volume is exhaled.
By adding the residual volume and vital capacity, you can obtain a value for the total lung capacity.
The total lung capacity is the maximum amount of air that can fill the lungs.
The vital capacity is the amount of air that can be exhaled after fully inhaling.
The tidal volume is the amount of air inhaled during normal, relaxed breathing.
The expiratory reserve volume is the amount of air that can be forcibly exhaled after a normal exhalation.
The inspiratory reserve volume is the amount of air that can be forcibly inhaled after a normal inhalation.
The residual volume is the amount of air still remaining in the lungs after the expiratory reserve volume is exhaled.
By adding the residual volume and vital capacity, you can obtain a value for the total lung capacity.
← Didn't Know|Knew It →
Both the sympathetic and the parasympathetic nervous systems are essential for homeostasis and for survival. For example, when we are trying to run away from a threat, the sympathetic nervous system is in full effect to allow us to escape from danger. However, when there is no obvious threat, the parasympathetic nervous system tends to be more in control.
There are similarities and differences between the sympathetic and the parasympathetic nervous systems. In preganglionic nerve fibers, both the sympathetic and the parasympathetic nervous system utilize the neurotransmitter acetylcholine. Closer to the target organ, the parasympathetic nervous system remains dependent on acetylcholine whereas norepinephrine and epinephrine are the predominant neurotransmitters utilized by the sympathetic nervous system.
When norepinephrine and epinephrine bind to their receptors, different effects are carried out based on the type of receptor, affinity, and location of the receptor. For example, epinephrine has a higher affinity for the beta-2 receptor. When epinephrine binds to the beta-2 receptor, common effects include vasodilation and bronchodilation. Norepinephrine has a stronger affinity for the alpha-1, alpha-2 and beta-1 receptors. When norepinephrine binds to its receptor, common effects on the body include vasoconstriction (alpha-1), increased heart rate (beta-1) and uterine contraction (alpha-1).
When a patient has a severe allergic reaction, a common prescribed drug is epinephrine. Which of the follow best explains the effects of epinephrine on a patient experiencing a severe allergic reaction?
Both the sympathetic and the parasympathetic nervous systems are essential for homeostasis and for survival. For example, when we are trying to run away from a threat, the sympathetic nervous system is in full effect to allow us to escape from danger. However, when there is no obvious threat, the parasympathetic nervous system tends to be more in control.
There are similarities and differences between the sympathetic and the parasympathetic nervous systems. In preganglionic nerve fibers, both the sympathetic and the parasympathetic nervous system utilize the neurotransmitter acetylcholine. Closer to the target organ, the parasympathetic nervous system remains dependent on acetylcholine whereas norepinephrine and epinephrine are the predominant neurotransmitters utilized by the sympathetic nervous system.
When norepinephrine and epinephrine bind to their receptors, different effects are carried out based on the type of receptor, affinity, and location of the receptor. For example, epinephrine has a higher affinity for the beta-2 receptor. When epinephrine binds to the beta-2 receptor, common effects include vasodilation and bronchodilation. Norepinephrine has a stronger affinity for the alpha-1, alpha-2 and beta-1 receptors. When norepinephrine binds to its receptor, common effects on the body include vasoconstriction (alpha-1), increased heart rate (beta-1) and uterine contraction (alpha-1).
When a patient has a severe allergic reaction, a common prescribed drug is epinephrine. Which of the follow best explains the effects of epinephrine on a patient experiencing a severe allergic reaction?
Tap to reveal answer
Epinephrine binds to the beta-2 receptor. The binding of epinephrine to the beta-2 receptor causes bronchodilation by relaxing the smooth muscles surrounding the airway. The relaxation of the smooth muscles around the airway increases the airway diameter and therefore allows the patient to breathe easier.
Epinephrine binds to the beta-2 receptor. The binding of epinephrine to the beta-2 receptor causes bronchodilation by relaxing the smooth muscles surrounding the airway. The relaxation of the smooth muscles around the airway increases the airway diameter and therefore allows the patient to breathe easier.
← Didn't Know|Knew It →
The carbonic anhydrase reaction is shown below.
Which of the following outcomes seems the most reasonable for someone who has an increase in blood CO2 levels during exercise?
The carbonic anhydrase reaction is shown below.
Which of the following outcomes seems the most reasonable for someone who has an increase in blood CO2 levels during exercise?
Tap to reveal answer
The individual's blood pH level will decrease (become more acidic). The increase in CO2 will cause the carbonic anhydrase reaction to shift to the right, increasing the concentration of protons (H+) in the blood. The individual can raise their pH level back to normal by breathing out all of the excess CO2. This accounts, in part, for increased respiration rates during exercise (along with the increased demand for oxygen).
The individual's blood pH level will decrease (become more acidic). The increase in CO2 will cause the carbonic anhydrase reaction to shift to the right, increasing the concentration of protons (H+) in the blood. The individual can raise their pH level back to normal by breathing out all of the excess CO2. This accounts, in part, for increased respiration rates during exercise (along with the increased demand for oxygen).
← Didn't Know|Knew It →
Whales are active at great, underwater depths for extended periods of time. Which of the following would LEAST contribute to such an ability?
Whales are active at great, underwater depths for extended periods of time. Which of the following would LEAST contribute to such an ability?
Tap to reveal answer
When whales dive to great depths, they are unable to replenish oxygen from the water's surface. Several adaptive characteristics allow for the whales to maintain adequate oxygen supply to their tissues: large lung capacity (to absorb a greater amount of oxygen when breathing), selective arterial constriction (to restrict blood flow to non-essential tissues and thus prevent inefficient oxygen consumption), high cellular tolerance for carbon dioxide (CO₂ will build up over time without gas exchange), and large muscle myoglobin concentrations (to replenish oxygen supply to muscles as necessary).
A high basal metabolic rate, however, would increase the demand for oxygen and thus would not be an adaptive characteristic for whales in order to maintain themselves at great, watery depths without an external supply of oxygen.
When whales dive to great depths, they are unable to replenish oxygen from the water's surface. Several adaptive characteristics allow for the whales to maintain adequate oxygen supply to their tissues: large lung capacity (to absorb a greater amount of oxygen when breathing), selective arterial constriction (to restrict blood flow to non-essential tissues and thus prevent inefficient oxygen consumption), high cellular tolerance for carbon dioxide (CO₂ will build up over time without gas exchange), and large muscle myoglobin concentrations (to replenish oxygen supply to muscles as necessary).
A high basal metabolic rate, however, would increase the demand for oxygen and thus would not be an adaptive characteristic for whales in order to maintain themselves at great, watery depths without an external supply of oxygen.
← Didn't Know|Knew It →