Gas exchange in humans：練習題

Which feature is characteristic of a human gas exchange surface?

The diagram shows a cross-section of the human trachea. A specific tissue is observed as a series of C-shaped rings.

What is the primary function of this tissue during the process of inhalation, when the pressure inside the trachea falls below atmospheric pressure?

A diagram of the human gas exchange system shows the pathway of air from the nasal cavity to the alveoli.

At which point in the system does the air first encounter the structure supported by cartilage that then branches into two smaller tubes, each entering a lung?

Which statement correctly describes the diaphragm when it is in a relaxed state?

A student is investigating the rate of diffusion in the human gas exchange system. They observe that oxygen molecules must pass through several layers to reach the red blood cells.

Which combination of features describes the shortest total distance for oxygen to travel from the alveolar air space to the haemoglobin inside a red blood cell?

State the name of the hair-like structures found on the cells lining the trachea that help move mucus away from the lungs.

A person transitions from resting to sprinting. Explain the link between this increased physical activity and the resulting change in the rate and depth of breathing, specifically mentioning what the brain detects.

The trachea is kept open by C-shaped rings of a specific tissue. Identify this tissue and explain why its structural property is essential for ventilation during the pressure changes of breathing.

The diagram illustrates a common laboratory experiment used to compare the carbon dioxide content of inspired and expired air.

(a) Identify the reagent used in both flasks and describe the appearance of this reagent at the start of the experiment.

(b) Predict which flask (Flask 1 for inspired air or Flask 2 for expired air) will show a faster change in appearance and state what that change will be.

A student investigates the differences in the composition of gases between inspired and expired air.

(a) Describe a test the student could use to compare the carbon dioxide concentration in inspired and expired air, and state the expected results.

(b) Explain why the percentage of water vapour in expired air is described as saturated, while it is variable in inspired air.