Human Gas Exchange: Practice Questions

Which component of tobacco smoke is primarily responsible for causing addiction in smokers?

The diagram illustrates the movement of the rib cage and diaphragm during a specific phase of breathing. Which set of muscle actions and resulting movements describes the phase shown?

The graph shows the change in thoracic volume during one complete breathing cycle. Based on the graph, which of the following describes the relationship between thoracic volume and air pressure that causes air to enter the lungs?

The lining of the human trachea contains specialized cells that help protect the respiratory system. What is the primary function of the mucus produced by these cells?

The diagram shows the state of the human thorax during one phase of the breathing cycle. Which of the following describes the actions of the muscles and the change in thoracic volume during this phase?

State one structural adaptation of the alveoli that allows for the rapid exchange of gases between the lungs and the blood.

Based on the position of the diaphragm shown in the diagram of the thorax, identify whether the person is inhaling or exhaling, and explain how the change in thoracic volume causes the movement of air.

Tobacco smoke contains both tar and carbon monoxide. Explain how the combination of these two substances reduces the overall rate of aerobic respiration in the body cells of a long-term smoker.

The diagram shows part of the human respiratory system and a magnified view of the site where gas exchange occurs.

(a) Identify the structures labeled A and B. (2 points)

(b) Structure A contains C-shaped rings of cartilage. Explain the function of these rings during the process of breathing. (1 point)

(c) Structure B is lined with a thin film of moisture. Describe how this moisture facilitates the exchange of gases. (1 point)

The human respiratory system is designed to facilitate the efficient exchange of oxygen and carbon dioxide.

(a) Describe the actions of the external intercostal muscles and the diaphragm during the process of inhalation. (2 points)

(b) The diagram shows a cross-section of an alveolus and a capillary. Explain how the structure of these two components is adapted to provide a short diffusion distance for gas exchange. (2 points)

(c) Explain how the ciliated cells and mucus-secreting cells in the trachea work together to protect the respiratory system from dust and pathogens. (2 points)

(d) State the names of the two types of branching tubes that air passes through between the trachea and the alveoli, and explain how this branching structure benefits gas exchange. (2 points)