Final answer:
The posterior or vertebral end of a rib is flatter than the anterior or sternal end. The posterior end articulates with the thoracic vertebrae, while the anterior end typically ends in costal cartilage and attaches to the sternum directly or indirectly, contributing to the thoracic cage.
Step-by-step explanation:
The question is asking to identify how the posterior or vertebral end of a rib compares to the anterior or sternal end. The posterior end of the rib, which includes the head of the rib, is characterized by its articulation with the costal facets on the thoracic vertebrae and the tubercle of the rib which articulates with the transverse process of the vertebra. The anterior end of each rib ends in costal cartilage and attaches to the sternum, either directly or indirectly, or not at all in the case of the floating ribs. Given the structural differences and considering that the vertebrae provide a sturdier attachment point than the softer costal cartilage, the posterior end is flatter compared to the more cylindrical anterior end where the costal cartilage meets the sternum.
The thoracic cage is an important structure in the human body as it houses and protects vital organs such as the heart and lungs. The sternum consists of the manubrium, body, and xiphoid process. The ribs, part of this cage, are numbered 1-12 and are categorized as true ribs, false ribs, and floating ribs, with variations in their anterior attachment. The sternum provides a robust central support to which the true ribs directly attach.