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
Zygomatic bone seen in humans, with the bar between the orbit and fenestra vanishing entirely, and only the lower boundary of the fenestra remaining, as the zygomatic arch. The term "zygomatic" derives from the Greek Ζυγόμα "zygoma" meaning "yoke". The zygomatic bone is occasionally referred to as the zygoma, but this term may also refer to the zygomatic arch. Zygomatic bone In the human skull, the zygomatic bone (cheekbone or malar bone) is a paired irregular bone which articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. It is situated at the upper and lateral part of