![]() The internal thoracic artery gives off sternal, anterior intercostal, perforating and non-collateral branches. The blood supply of the sternum is mainly derived from the medial horizontal branches of the right and left internal thoracic arteries which originate directly from the first part of the subclavian arteries bilaterally or occasionally originate from a common trunk. The first part of the sternum to form during embryogenesis is the manubrium sterni followed by the sternal body and the xiphoid process. ![]() The four sternebrae that lie in between represent the body of the sternum. The superior-most sternebra and the inferior-most sternebra ultimately represent the manubrium sterni and xiphoid process, respectively. The cartilaginous sternal model consists of six horizontal divisions known as sternebrae. In the 7th week of intrauterine life, the mesenchyme condenses resulting in the formation of the primary cartilaginous model of the three sternal segments (manubrium sterni, the body of the sternum and the xiphoid process). ![]() By the 10th week of intrauterine life, these two sternal bands arise from the parietal layer of the lateral plate mesoderm bilaterally, then convert into pre-cartilaginous structures that migrate and fuse in a craniocaudal direction to form the sternal plate. During the 6th developmental week of fetal life, the sternum develops independently from a pair of sternal bands called “sternal bars” which are concentrations of mesenchymal cells on either side of the midline. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |