Which component contributes to the central tendon of the diaphragm?

The central tendon of the diaphragm is primarily formed from the septum transversum, which is a mesodermal tissue structure that plays a crucial role in the development of the diaphragm during embryogenesis. The septum transversum initially forms a partition that separates the thoracic cavity from the abdominal cavity and eventually contributes to the central tendon by fusing with other structures as the diaphragm develops.

Understanding the contributions to the diaphragm's structure is important for discerning how various embryonic structures contribute to its formation. The septum transversum becomes more pronounced as the diaphragm descends and expands laterally, creating the central tendon that serves as an attachment point for the muscle fibers of the diaphragm.

In contrast, while components like the pleuroperitoneal membranes and cervical somites are involved in the overall development and innervation of the diaphragm, they do not directly contribute to the central tendon itself. The costal arch, which includes the margins of the lower ribs, plays a role in the muscle attachments of the diaphragm rather than in forming the central tendon. Thus, the septum transversum is the correct and primary structure responsible for contributing to this critical part of the diaphragm.