NSE 13A/B Lecture Notes - Omohyoid Muscle, Facial Nerve, Zygomatic Arch
Document Summary
The skull is a rigid bony box that protects the brain and special sense organs, and it includes the bones of the cranium and the face. The adjacent cranial bones unite at meshed immovable joints called the sutures. The bones are not firmly joined at birth; this allows for the mobility and change in shape needed for the birth process. The coronal suture crowns the head from ear to ear at the union of the frontal and parietal bones. The sagittal suture separates the head lengthwise between the two parietal bones. The lambdoid suture separates the parietal bones crosswise from the occipital bone. The 14 facial bones also articulate at sutures (note the nasal bone, zygomatic bone, and maxilla), except for the mandible (the lower jaw). The expressions are formed by the facial muscles which are mediated by cranial nerve vii, the facial nerve.