Sacrum apex is directed downward and presents an oval facet for articulation with the coccyx. The sacral canal as a continuation of the vertebral canal runs throughout the greater part of the sacrum. The sacral angle is the angle formed by the true conjugate with the two pieces of sacrum. Normally it is greater than 60 degrees. A sacral angle of lesser degree suggests funneling of the pelvis. The sacral promontory marks part of the border of the pelvic inlet, and comprises the iliopectineal line and the linea terminalis. The sacral promontory articulates with the last lumbar vertebra to form the
Human body Human body The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a head, neck, trunk (which includes the thorax and abdomen), arms and hands, legs and feet. The study of the human body involves anatomy, physiology, histology and embryology. The body varies anatomically in known ways. Physiology focuses on the systems and organs of the human body and their functions. Many systems and mechanisms interact in order to maintain homeostasis,