Sciatic nerve from spinal nerves L4 to S3. It contains fibers from both the anterior and posterior divisions of the lumbosacral plexus. The sciatic nerve is formed from the L4 to S3 segments of the sacral plexus, a collection of nerve fibres that emerge from the sacral part of the spinal cord. The fibres unite to form a single nerve in front of the piriformis muscle. The nerve passes beneath piriformis and through the greater sciatic foramen, exiting the pelvis. From here, it travels down the posterior thigh to the popliteal fossa. The nerve travels in the posterior compartment of the thigh
Squamous part of the frontal bone the supraorbital margins the squamous part projects downward to a level below that of the zygomatic processes. It meets the nasal bone where it presents a rough, uneven serrated notch known as the nasal notch, and this articulates on either side of the middle line with the nasal bone, and laterally with the frontal process of the maxilla and with the lacrimal. This part is sometimes called the nasal part of frontal bone. The term nasion is applied to the middle of the frontonasal suture. From the center of the notch the nasal process projects downward and forward beneath the