These scroll-like bones form part of the inferior lateral wall of the nasal cavity and project into the nasal cavity. The two inferior nasal conchae, which are inferior to the middle nasal conchae of the ethmoid bone are separate bones, not part of the ethmoid bone. The two L-shaped palatine bones form the posterior portion of the hard palate, part of the floor and lateral wall of the nasal cavity as well as a small portion of the floors of the orbits. It houses the lacrimal sack which gathers tears and passes them in to the nasal cavity. Just For Fun The lacrimal bones each contain a vertical grove formed with the maxilla called the lacrimal fossa. They are the smallest facial bones and forma part of the medial wall of each orbit (eye socket). The two lacrimal bones are thin and slightly resemble a fingernail. The temporal process of the zygomatic bone projects posteriorly and articulates with the zygomatic process of the temporal bone to form the zygomatic arch. The two zygomatic bones (cheek bones) form the prominences of the cheeks and part of the lateral wall and floor of each orbit. They form part of the floor of the orbits and part of the lateral walls of the nasal cavity as well as most of the hard palate (roof of the mouth). The two maxilla unite to form the upper jaw bone. The rest of the supporting tissue is cartilage. The two nasal bones meet at the mid-line of the face and form the bridge of the nose. It also forms the medial wall of the orbits (eye sockets). It is a major supporting structure of the nasal cavity as it forms the superior portion of the nasal septum and most of the superior sidewalls of the nasal cavity. The ethmoid bone is located anterior to the sphenoid and posterior to the nasal bones. The shape of the sphenoid resembles a butterfly with outstretched wings. The sphenoid sits posteriorly and slightly superior to the nasal cavity and forms part of the floor, side walls and rear wall of the orbit. Anteriorly it joins with the frontal bone, laterally it joins with the temporal bones and posteriorly with the occipital bone. It articulates with all the other cranial bones and holds them together. The sphenoid bone sits at the middle part of the base of the skull. The external occipital protuberance (EOP) is the most prominent mid-line projection on the posterior surface of the bone just above the foramen magnum. The foramen magnum is in the inferior part of the bone. The occipital bone forms the posterior part and majority of the base of the cranium. The mandibular fossa and the articular tubercle articulate with the mandible (lower jawbone) to form the temporomandibular joint (TMJ). (Many people call this the cheek bone.)Ī socket called the mandibular fossa is located on the inferior posterior surface of the zygomatic process of each temporal bone. The zygomatic process of the temporal bone and the temporal process of the zygomatic bone form the zygomatic arch. The two temporal bones make up the lateral aspects of the cranium and part of the cranial floor. The two parietal bones form the greater portion of the sides and roof of the cranial cavity. Soon after birth the left and right sides of the frontal bone are joined by the metopic suture which usually disappears between 6 and 8 years old. The frontal bone forms the forehead, the roofs of the orbits (eye sockets), and most of the anterior part of the cranial floor. The cranial bones protect and stabilize the position of the brain, blood vessels, lymphatic vessels and nerves through the attachment of their inner surfaces to meninges (membranes) The outer surface of the cranial bones provide attachment sites for muscles that move the head and face. The skull has many surface markings called fissures and foramina that nerves and blood vessels pass through. Just For Fun – In the manual healing therapy called Cranial Sacral Therapy the therapist will gently manipulate these cranial joints. Sutures are the immovable joints the fuse most of the skull together. Other than these bones the mandible is considered the only movable bone of the skull. (3 per ear) They are called’ the malleus, incus and stapes. There are 6 auditory ossicles involved in hearing which are located in the temporal bones. The skull bones are grouped into two categories cranial bones and facial bones. The cranium has 8 bones and rest on the top of the vertebral column.
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