Question

The bronchioles are: a. kept open by cartilage rings b. larger than the bronchi c. located between the bronchi and the alveoli d. an important site of gas exchange in the lungs

Short answer

C. located between the bronchi and the alveoli

Step-by-step solution

Understanding the Bronchioles

The bronchioles are small air passages in the lungs that branch from the larger bronchi and lead to the alveoli.

Evaluating Option A

Option A states that bronchioles are kept open by cartilage rings. This is incorrect. Unlike the bronchi, bronchioles do not have cartilage rings; they are kept open by the elastic fibers around them.

Evaluating Option B

Option B claims bronchioles are larger than the bronchi. This is inaccurate. Bronchioles are smaller airways that branch off from the larger bronchi.

Evaluating Option C

Option C states the bronchioles are located between the bronchi and the alveoli. This is correct. The bronchioles serve as passageways that channel air from the bronchi to the alveoli.

Evaluating Option D

Option D claims that bronchioles are an important site of gas exchange in the lungs. While bronchioles play a role in directing air to the alveoli, gas exchange primarily occurs in the alveoli themselves.

Conclusion

Based on the evaluations, the correct answer is Option C.

Key concepts

bronchi

The bronchi are large airways in the respiratory tract that lead from the trachea into the lungs. They are essential for transporting air into the lungs. Each bronchi splits into progressively smaller bronchi and bronchioles which further channel air deeper into the lungs. It's important to note that the bronchi are supported by cartilage rings which help keep them open, ensuring a clear passageway for air.

Key points to understand about bronchi include:

• They originate from the trachea and branch into each lung.
• Have cartilage rings for structural support and to keep them open.
• Gradually divide into smaller bronchi and eventually into bronchioles.

This structure is crucial for efficient air delivery into the lung tissue.

alveoli

Alveoli are tiny balloon-like structures in the lungs where the magic of gas exchange takes place. Located at the ends of the bronchioles, alveoli are surrounded by a network of capillaries which carry blood.

Here's why alveoli are important:

• They provide a large surface area for gas exchange.
• Oxygen from inhaled air passes through the walls of the alveoli into the blood in the capillaries.
• Carbon dioxide from the blood passes into the alveoli to be exhaled.

The thin walls and extensive surface area make alveoli exceptionally well-suited for gas exchange, crucial for supplying oxygen to the body and removing carbon dioxide.

gas exchange in lungs

Gas exchange in the lungs is a vital process where oxygen is absorbed into the bloodstream, and carbon dioxide is expelled from the body. This exchange happens primarily in alveoli, small sacs in the lungs.

Here's a simple breakdown of the process:

• Inhaled air reaches the alveoli where oxygen crosses into the blood.
• Hemoglobin in red blood cells binds with the oxygen and transports it throughout the body.
• At the same time, carbon dioxide from the blood diffuses into the alveoli.
• This carbon dioxide is expelled from the body when we exhale.

This swap ensures that our blood is rich in oxygen, which is necessary for cells to produce energy, and helps remove the metabolic waste product, carbon dioxide, from our bodies.