Hip bone portion. The inferior pubic ramus is thin and flat. It passes laterally and downward from the medial end of the superior ramus. It becomes narrower as it descends and joins with the inferior ramus of the ischium below the obturator foramen. The hip bone is ossified from eight centers: three primary, one each for the ilium, ischium, and pubis, and five secondary, one each for the iliac crest, the anterior inferior spine (said to occur more frequently in the male than in the female), the tuberosity of the ischium, the pubic symphysis (more frequent in the female than in the
Mastoid part of the temporal bone is derived from the Greek word for “breast,” a reference to the shape of this bone. Mastoid part of the temporal bone The mastoid part of the temporal bone is the back part of the temporal bone. Its rough surface gives attachment to various muscles and it has openings for the transmission of blood vessels. From its borders the mastoid part articulates with two other bones. Its outer surface is rough, and gives attachment to the occipitalis and posterior auricular muscles. It is perforated by numerous foramina (holes); one of these, of large size, situated near the posterior border, is