Question 1

In humans, arterial PCO₂ is monitored carefully by breathing centers in the medulla, and any changes in it lead quickly to changes in respiratory rate.The actual stimulus that leads to increased respiratory gas exchange is/are

Accepted Answer

Changes in arterial PCO2 (carbon dioxide) are the main stimulus for increased respiratory gas exchange. As CO2 levels increase, hydrogen ions are produced, which leads to a decrease in pH (acidosis). The chemoreceptors in the medulla detect this change in pH and signal for increased respiratory rate to eliminate CO2 and bring the pH back to normal. Therefore, hydrogen ions are the correct answer. Choices A, B, C, and E are not directly related to respiratory gas exchange stimulation.

Question 2

In fish gas exchange systems, blood flows through gill lamellae in a direction opposite to water flow, a phenomenon known as _______.

Accepted Answer

The answer of In fish gas exchange systems, blood flows...

Question 3

The carotid and aortic bodies

Accepted Answer

The carotid and aortic bodies are chemoreceptors that respond to significant declines in partial pressure of oxygen (PO2) in the blood, not PO₂.

Question 4

The notation PO₂ stands for the _______ of oxygen.

Accepted Answer

The answer of The notation PO₂ stands for the _______...

Question 5

Nodes that are sensitive to O₂ and blood pressure levels are located on the

Accepted Answer

The aorta and carotid arteries contain baroreceptors that are sensitive to changes in blood pressure and O₂ levels. These receptors communicate with the brainstem to help regulate blood pressure and maintain homeostasis. The other options do not contain baroreceptors or are not directly involved in blood pressure regulation.

Question 6

An unusual feature of the lungs of _______ is that they expand and contract relatively little during a breathing cycle.They also contract during inhalation and expand during exhalation.

Accepted Answer

The answer of An unusual feature of the lungs of...

Question 7

The breathing tubes of insects are called _______.

Accepted Answer

The answer of The breathing tubes of insects are called...

Question 8

Neural control of breathing is a function of the

Accepted Answer

The medulla oblongata is responsible for the neural control of breathing. It contains neurons that regulate the rate and depth of breathing based on the pH and carbon dioxide levels in the blood. The diaphragm is the primary muscle used for breathing, but it is controlled by signals from the medulla oblongata. The cerebellum is responsible for movement and balance, the olfactory lobe is responsible for smell, and the spinal cord is responsible for relaying sensory and motor signals throughout the body.

Question 9

The breathing center in humans initiates ventilation in response to

Accepted Answer

The breathing center in humans initiates ventilation primarily in response to an increase in CO2 levels (CO₂), which leads to a decrease in blood pH, signaling the need for increased breathing to expel CO2 and restore normal pH levels.

Question 10

Emergency medical technicians (EMTs) suspect that a victim of a serious accident has suffered an injury to the brainstem because his breathing has continued but is irregular.Specifically, the injury is likely to

Accepted Answer

The brainstem is responsible for regulating vital functions, including breathing. The medulla and the pons, parts of the brainstem, play crucial roles in controlling breathing patterns. An injury between the pons and medulla could disrupt normal breathing rhythms, leading to irregular breathing without necessarily stopping it, as described in the scenario.

Question 11

Refer to the figure showing feedback information that controls breathing in humans.  The nerves labeled 1 are _______; the structure labeled 2 senses the _______; and the nerve labeled 3 is _______.

Accepted Answer

The nerves labeled 1 are sensory nerves, which means they are responsible for sensing information. The structure labeled 2 senses the hydrogen ions in the cerebrospinal fluid, which regulates the acidity of the brain. The nerve labeled 3 is a motor nerve that stimulates the diaphragm to contract, allowing for breathing to occur. Therefore, the correct answer is B.

Question 12

Refer to the figure showing a death's head hawkmoth larva.  The series of holes labeled A in this larva are _______, which are part of the breathing system.They open to allow for gas exchange and close to prevent water loss.

Accepted Answer

The answer of Refer to the figure showing a death's...

Question 13

In addition to possessing lungs, birds have _______, which receive inhaled air but are not gas exchange structures.

Accepted Answer

The answer of In addition to possessing lungs, birds have...

Question 14

Chemosensors on the surface of the medulla are sensitive to

Accepted Answer

Chemosensors on the surface of the medulla are sensitive to changes in the pH of the cerebrospinal fluid. These chemosensors play a critical role in regulating breathing rate and rhythm based on the level of carbon dioxide and pH in the blood.

Question 15

External _______ are highly branched folds of the body surface of some animals that are involved in gas exchange.

Accepted Answer

The answer of External _______ are highly branched folds of...

Question 16

Breathing rhythm is generated in the _______ and is influenced by variation in levels of _______ in the blood.

Accepted Answer

The breathing rhythm is generated in the medulla, a part of the brainstem, and is influenced by variations in levels of both carbon dioxide (CO2) and oxygen (O2) in the blood.

Question 17

There are no active transport mechanisms for respiratory gases.Therefore, the only means by which respiratory gases are exchanged is _______.

Accepted Answer

The answer of There are no active transport mechanisms for...

Question 18

In Fick's law of diffusion, the term (P₁ - P₂)/L refers to the _______ gradient.

Accepted Answer

The answer of In Fick's law of diffusion, the term...

Question 19

Breathing mechanisms ventilate the environmental side of the gas exchange surface, while circulatory systems _______ the internal side of the surface.

Accepted Answer

The answer of Breathing mechanisms ventilate the environmental side of...

Question 20

The respiratory rate in humans and other mammals changes primarily in response to

Accepted Answer

The respiratory rate is primarily regulated by the levels of carbon dioxide (PCO2) in the blood, as it affects the pH of the blood and cerebrospinal fluid, which is detected by chemoreceptors.

Quiz 48: Gas Exchange

In humans, arterial PCO₂ is monitored carefully by breathing centers in the medulla, and any changes in it lead quickly to changes in respiratory rate.The actual stimulus that leads to increased respiratory gas exchange is/are

In fish gas exchange systems, blood flows through gill lamellae in a direction opposite to water flow, a phenomenon known as _______.

The carotid and aortic bodies

The notation PO₂ stands for the _______ of oxygen.

Nodes that are sensitive to O₂ and blood pressure levels are located on the

An unusual feature of the lungs of _______ is that they expand and contract relatively little during a breathing cycle.They also contract during inhalation and expand during exhalation.

The breathing tubes of insects are called _______.

Neural control of breathing is a function of the

The breathing center in humans initiates ventilation in response to

Emergency medical technicians (EMTs) suspect that a victim of a serious accident has suffered an injury to the brainstem because his breathing has continued but is irregular.Specifically, the injury is likely to

Refer to the figure showing feedback information that controls breathing in humans. The nerves labeled 1 are ___; the structure labeled 2 senses the _; and the nerve labeled 3 is _____.

Refer to the figure showing a death's head hawkmoth larva. The series of holes labeled A in this larva are _______, which are part of the breathing system.They open to allow for gas exchange and close to prevent water loss.

In addition to possessing lungs, birds have _______, which receive inhaled air but are not gas exchange structures.

Chemosensors on the surface of the medulla are sensitive to

External _______ are highly branched folds of the body surface of some animals that are involved in gas exchange.

Breathing rhythm is generated in the _ and is influenced by variation in levels of _ in the blood.

There are no active transport mechanisms for respiratory gases.Therefore, the only means by which respiratory gases are exchanged is _______.

In Fick's law of diffusion, the term (P₁ - P₂)/L refers to the _______ gradient.

Breathing mechanisms ventilate the environmental side of the gas exchange surface, while circulatory systems _______ the internal side of the surface.

The respiratory rate in humans and other mammals changes primarily in response to

Quiz 48: Gas Exchange

In humans, arterial PCO2 is monitored carefully by breathing centers in the medulla, and any changes in it lead quickly to changes in respiratory rate.The actual stimulus that leads to increased respiratory gas exchange is/are

In fish gas exchange systems, blood flows through gill lamellae in a direction opposite to water flow, a phenomenon known as _______.

The carotid and aortic bodies

The notation PO2 stands for the _______ of oxygen.

Nodes that are sensitive to O2 and blood pressure levels are located on the

An unusual feature of the lungs of _______ is that they expand and contract relatively little during a breathing cycle.They also contract during inhalation and expand during exhalation.

The breathing tubes of insects are called _______.

Neural control of breathing is a function of the

The breathing center in humans initiates ventilation in response to

Emergency medical technicians (EMTs) suspect that a victim of a serious accident has suffered an injury to the brainstem because his breathing has continued but is irregular.Specifically, the injury is likely to

Refer to the figure showing feedback information that controls breathing in humans. The nerves labeled 1 are _______; the structure labeled 2 senses the _______; and the nerve labeled 3 is _______.

Refer to the figure showing a death's head hawkmoth larva. The series of holes labeled A in this larva are _______, which are part of the breathing system.They open to allow for gas exchange and close to prevent water loss.

In addition to possessing lungs, birds have _______, which receive inhaled air but are not gas exchange structures.

Chemosensors on the surface of the medulla are sensitive to

External _______ are highly branched folds of the body surface of some animals that are involved in gas exchange.

Breathing rhythm is generated in the _______ and is influenced by variation in levels of _______ in the blood.

There are no active transport mechanisms for respiratory gases.Therefore, the only means by which respiratory gases are exchanged is _______.

In Fick's law of diffusion, the term (P1 - P2)/L refers to the _______ gradient.

Breathing mechanisms ventilate the environmental side of the gas exchange surface, while circulatory systems _______ the internal side of the surface.

The respiratory rate in humans and other mammals changes primarily in response to

In humans, arterial PCO₂ is monitored carefully by breathing centers in the medulla, and any changes in it lead quickly to changes in respiratory rate.The actual stimulus that leads to increased respiratory gas exchange is/are

The notation PO₂ stands for the _______ of oxygen.

Nodes that are sensitive to O₂ and blood pressure levels are located on the

Refer to the figure showing feedback information that controls breathing in humans. The nerves labeled 1 are ___; the structure labeled 2 senses the _; and the nerve labeled 3 is _____.

Breathing rhythm is generated in the _ and is influenced by variation in levels of _ in the blood.

In Fick's law of diffusion, the term (P₁ - P₂)/L refers to the _______ gradient.