What structure bridges the gap in the dorsal part of the trachea?

In the dorsal part of the trachea, the gap is bridged by smooth muscle. This smooth muscle plays a crucial role in regulating the diameter of the trachea, which can help adjust airflow during breathing. Specifically, this muscle allows for changes in the trachea's flexibility and diameter, enabling it to stretch during inhalation and contract during exhalation, thus facilitating efficient airflow.

The trachea is largely supported by C-shaped cartilage rings that maintain its structural integrity and keep the airway open. However, these rings do not completely encircle the trachea; the open part, which faces the esophagus, is where the smooth muscle is located. This anatomical arrangement allows the esophagus to expand when food is swallowed without being constrained by rigid cartilage.

This functional role of the smooth muscle in bridging the dorsal gap in the trachea is essential for both respiratory efficiency and the protection of adjacent structures.