Free Practice Quiz Question List

5 Respiratory System Physiology Online Quiz Questions

Use this free practice quiz with 20 questions to review 5 Respiratory System Physiology, test your knowledge, and prepare for your next test or exam.

20 questions

Written response

1 point

What is the physiological term for gas exchange between the alveoli and pulmonary capillary blood?

Written response

1 point

A person has a tidal volume of $500\ \text{mL/breath}$ , dead-space volume of $150\ \text{mL/breath}$ , and breathing rate of $12\ \text{breaths/min}$ . Calculate alveolar ventilation using $(\text{tidal volume} - \text{dead-space volume}) \times \text{breathing rate}$ . Enter the value in mL/min.

Choose one

1 point

During quiet inhalation, the diaphragm contracts and flattens. Which change causes air to flow into the lungs?

A
Lung volume decreases, raising alveolar pressure above atmospheric pressure.
B
Lung volume increases, lowering alveolar pressure below atmospheric pressure.
C
Lung volume increases, raising alveolar pressure above atmospheric pressure.
D
Lung volume decreases, lowering alveolar pressure below atmospheric pressure.

Choose one

1 point

In the lungs, alveolar oxygen partial pressure exceeds that of incoming pulmonary-capillary blood, while incoming blood has a higher carbon dioxide partial pressure than alveolar air. Which direction does each gas diffuse?

A
Oxygen moves from blood to alveoli, and carbon dioxide moves from alveoli to blood.
B
Both oxygen and carbon dioxide move from alveoli to blood.
C
Oxygen moves from alveoli to blood, and carbon dioxide moves from blood to alveoli.
D
Both oxygen and carbon dioxide move from blood to alveoli.

Written response

1 point

A person has a tidal volume of 500 mL, a dead-space volume of 150 mL, and breathes 12 times per minute. What is the alveolar ventilation in mL/min? Use $(\text{tidal volume}-\text{dead-space volume})\times\text{breathing rate}$ .

Choose one

1 point

When arterial carbon dioxide rises, which response best describes how central chemoreceptors contribute to increased respiratory drive?

A
They primarily detect increased acidity in the fluid surrounding the brain, which can result when carbon dioxide enters it.
B
They primarily detect low oxygen directly in the carotid and aortic bodies.
C
They primarily detect increased oxygen in the fluid surrounding the brain.
D
They primarily detect reduced blood flow through the pulmonary capillaries.

True or false

1 point

True or false: Increased acidity shifts the oxygen–hemoglobin dissociation curve to the right, reducing hemoglobin's oxygen affinity and favoring oxygen release to tissues.

A
True
B
False

Written response

1 point

What is the name of the effect in which oxygenation of hemoglobin promotes carbon dioxide release?

Choose one

1 point

Which process describes how the largest share of carbon dioxide is transported from tissues in the blood?

A
Most carbon dioxide binds to hemoglobin, while chloride moves into plasma in exchange.
B
Most carbon dioxide remains dissolved in plasma, while bicarbonate moves into red blood cells.
C
Most carbon dioxide is converted to oxygen inside red blood cells and carried in plasma.
D
Most carbon dioxide is converted to bicarbonate in red blood cells, which moves into plasma in exchange for chloride.

Choose one

1 point

An alveolus receives little ventilation. Which local vascular response tends to improve ventilation–perfusion matching in the lungs?

A
Local pulmonary arterioles dilate, increasing blood flow to the poorly ventilated alveolus.
B
Local pulmonary arterioles constrict, tending to redirect blood toward better-ventilated regions.
C
Systemic arterioles constrict, stopping blood flow to all alveoli.
D
The poorly ventilated alveolus increases oxygen delivery by expanding its capillaries.

Choose one

1 point

Which statement best distinguishes the roles of the medulla and pons in respiratory control?

A
The medulla helps establish rhythm, while pontine input modifies the breathing pattern and transitions.
B
The pons establishes the basic rhythm, while the medulla only controls voluntary breathing.
C
The medulla and pons both act only as peripheral chemoreceptors.
D
The pons sends motor signals directly to the lungs, while the medulla controls blood-gas transport.

Choose one

1 point

Which explanation correctly connects cooperative oxygen binding to the shape and function of the oxygen–hemoglobin dissociation curve?

A
The curve is S-shaped because oxygen binding becomes harder after each oxygen molecule binds; the steep portion prevents unloading.
B
The curve is linear because each oxygen molecule binds independently; the plateau indicates rapid tissue unloading.
C
The curve is S-shaped because binding one oxygen molecule makes subsequent binding easier; the plateau supports high saturation in the lungs and the steeper portion supports unloading in tissues.
D
The curve is S-shaped because hemoglobin binds oxygen irreversibly; the plateau marks complete carbon dioxide release.

Choose one

1 point

During quiet exhalation, which change most directly helps move air out of the lungs?

A
The diaphragm contracts and lowers alveolar pressure below atmospheric pressure.
B
Elastic recoil reduces lung volume and raises alveolar pressure.
C
The external intercostal muscles contract and expand the chest.
D
Oxygen binding to hemoglobin pushes air out of the lungs.

Choose all

1 point

Select all the changes that peripheral chemoreceptors in the carotid and aortic bodies respond to.

A
Changes in arterial oxygen
B
Acidity of the fluid surrounding the brain as their primary stimulus
C
Changes in arterial carbon dioxide
D
Changes in arterial pH

Choose all

1 point

Select all statements that accurately describe oxygen transport by hemoglobin.

A
Most oxygen in blood is carried by hemoglobin rather than dissolved in plasma.
B
Hemoglobin binds oxygen permanently once it reaches the lungs.
C
A hemoglobin molecule can bind up to four oxygen molecules.
D
Hemoglobin can load oxygen where oxygen partial pressure is high and release it where that pressure is lower.

True or false

1 point

During exercise, increased ventilation occurs solely because arterial oxygen falls.

A
True
B
False

True or false

1 point

Only a small fraction of the oxygen in blood is carried dissolved in plasma.

A
True
B
False

Fill in the blank

1 point

Air that remains in the and does not reach gas-exchanging surfaces is called anatomical dead space.

Fill in the blank

1 point

Most oxygen in blood is carried bound to , a protein in red blood cells.

Open ended

1 point

A person begins exercising and their ventilation increases. Explain two inputs that can contribute to this response and how increased ventilation helps support respiratory homeostasis.