Inferior gluteal artery Inferior gluteal artery The inferior gluteal artery (sciatic artery), the smaller of the two terminal branches of the anterior trunk of the internal iliac artery, is distributed chiefly to the buttock and back of the thigh. It passes down on the sacral plexus of nerves and the piriformis muscle, behind the internal pudendal artery, to the lower part of the greater sciatic foramen, through which it escapes from the pelvis between the piriformis and coccygeus. It then descends in the interval between the greater trochanter of the femur and tuberosity of the ischium, accompanied by the sciatic and posterior femoral
Squamous part of occipital bone eminence. The upper two fossae are triangular and lodge the occipital lobes of the cerebrum; the lower two are quadrilateral and accommodate the hemispheres of the cerebellum. At the point of intersection of the four divisions of the cruciform eminence is the internal occipital protuberance. From this protuberance the upper division of the cruciform eminence runs to the superior angle of the bone, and on one side of it (generally the right) is a deep groove, the sagittal sulcus, which lodges the hinder part of the superior sagittal sinus. To the margins of this sulcus the falx cerebri is attached.