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 temporal bone Squamous part of temporal bone The squamous part of temporal bone, or temporal squama, forms the front and upper part of the temporal bone, and is scale-like, thin, and translucent. Its outer surface is smooth and convex; it affords attachment to the temporal muscle, and forms part of the temporal fossa; on its hinder part is a vertical groove for the middle temporal artery. A curved line, the "temporal line", or "supramastoid crest", runs backward and upward across its posterior part; it serves for the attachment of the temporal fascia, and limits the origin of the temporalis muscle. The boundary