Body of pubic bone of the Obturator internus. Body of pubic bone The body of pubic bone forms the wide, strong, medial and flat portion of the pubic bone which unite in the pubic symphysis. The rough superior edge of the "corpus", the pubic crest, ends laterally in the pubic tubercle. This tubercle, found roughly 3 cm from the pubic symphysis, is a distinctive feature on the lower part of the abdominal wall; important when localizing the superficial inguinal ring and the femoral canal of the inguinal canal. Its "internal surface" enters into the formation of the wall of the lesser pelvis and gives
Body of sphenoid bone the crest is an irregular opening leading into the corresponding sphenoidal air sinus. These sinuses are two large, irregular cavities hollowed out of the interior of the body of the bone, and separated from one another by a bony septum, which is commonly bent to one or the other side. They vary considerably in form and size, are seldom symmetrical, and are often partially subdivided by irregular bony laminae. Occasionally, they extend into the basilar part of the occipital bone nearly as far as the foramen magnum. They begin to be developed before birth, and are of a considerable size