A Level Biology Practice Exam

Which describes the main function of the trachea in the human body?

1. to aid in the digestion of food

2. to connect the throat to the esophagus

3. to facilitate airflow to the lungs

4. to distribute blood throughout the body

The correct answer is: to facilitate airflow to the lungs

The main function of the trachea in the human body is to facilitate airflow to the lungs. It acts as a vital airway passage, allowing air to travel from the larynx (voice box) down through the trachea and into the bronchi, which then branches off into the lungs. The structure of the trachea, which consists of c-shaped cartilage rings, helps maintain its open shape, ensuring a clear and unobstructed pathway for airflow during inhalation and exhalation. This is critical for respiration, as it supports gas exchange within the alveoli of the lungs, providing oxygen to the body and removing carbon dioxide. In contrast, aiding in the digestion of food is a function of the digestive system, particularly involving organs like the esophagus and stomach. Connecting the throat to the esophagus is also not accurate since the trachea connects to the throat (pharynx) but leads to the lungs rather than the esophagus, which is the passage for food. Lastly, distributing blood throughout the body is the role of the circulatory system, involving the heart and blood vessels, not the trachea.