Sacrospinous ligament Sacrospinous ligament The sacrospinous ligament (small or anterior sacrosciatic ligament) is a thin, triangular ligament in the human pelvis. The base of the ligament is attached to the outer edge of the sacrum and coccyx, and the tip of the ligament attaches to the spine of the ischium, a bone in the human pelvis. Its fibres are intermingled with the sacrotuberous ligament. The sacrotuberous ligament passes behind the sacrospinous ligament. In its entire length it covers the equally triangular coccygeus muscle, to which its closely connected. The presence of the ligament in the greater sciatic notch creates an opening (foramen),
Tympanic part of the temporal bone squama and mastoid part, and forms the anterior boundary of the tympanomastoid fissure. Its upper border fuses laterally with the back of the postglenoid process, while medially it bounds the petrotympanic fissure. The medial part of the lower border is thin and sharp; its lateral part splits to enclose the root of the styloid process, and is therefore named the "vaginal process". The central portion of the tympanic part is thin, as it gives rise to the bony inner two-thirds of the ear canal, and in 5 - 20% of skulls the lower surface is perforated by a hole, the