Anatomy & Physiology Respiratory #14

Question

Which structure, bound to the sealed chest that houses the lungs, flattens when contracted thus expanding the chest for inhalation?

Answers

  1. Ribs
    • Rationale:

      The ribs play a role in the respiratory cycle. However, the ribs do not flatten during inhalation.

  2. Trachea
    • Rationale:

      The trachea, or windpipe, is a structure of the lower respiratory tract. It does not flatten when contracted allowing the chest to expand for inhalation.

  3. Alveoli
    • Rationale:

      The alveoli is a structure of the lower respiratory tract. It is responsible for gas exchange but does not flatten when contracted allowing the chest to expand for inhalation.

  4. Diaphragm
    • Rationale:

      The diaphragm is a dome-shaped muscular partition that separates the thorax from the abdomen. It plays a major role in breathing, as its contraction increases the volume of the thorax thus allowing the chest to expand for inhalation.

Overview

The lung, a lower respiratory system structure that is found in a sealed cavity of the chest, is bound by the chest wall, ribs, and muscular diaphragm.

Explanation

Learning Outcomes

The diaphragm, a muscle, curves upward when released. During inspiration, the chest muscles move the ribs up and out thereby causing the diaphragm to move down. This, in turn, causes the chest cavity to enlarge and draws air into the passages of the respiratory system.

Test Taking Tip

Consider the function of each choice in regard to the respiratory system when determining the correct answer for this question.

Video Rationale