Which of the following structures is involved in the muscular components of the diaphragm?

The correct answer is based on the development of the diaphragm and the involvement of specific structures during its formation. The muscular components of the diaphragm arise primarily from the cervical somites, specifically from the cervical levels C3, C4, and C5, with the phrenic nerve providing innervation. This musculature is crucial for the diaphragm's function in respiration, as it contracts and relaxes to facilitate airflow into the lungs.

Cervical somites C5-7 contribute to the formation of the diaphragm's muscular tissue. These somites migrate down to the developing diaphragm region as it forms, contributing to the muscle fibers that enable contraction. The innervation from the phrenic nerve, which is derived from the cervical plexus of nerves, is essential for diaphragm movement and thus plays a crucial role in respiratory mechanics.

Other structures mentioned, such as the septum transversum, pleuroperitoneal membranes, and costal arch, have different roles in diaphragm development or anatomy but are not directly responsible for the muscular components of the diaphragm. The septum transversum forms a significant portion of the diaphragm but mainly contributes to the central tendon rather than the muscular portion. The pleuroperitoneal membranes are involved in closing the ple