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LIF101 Anatomy. Bone structures of the Skull: (Face and Cranium). The Human Skull. 22 flat bones Primary functions encase/protect brain provide framework for head Two parts: Cranium (egg) Facial region (mask). Cranium of Infant. Still mostly cartilage; bones incompletely ossified
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LIF101Anatomy Bone structures of the Skull: (Face and Cranium)
The Human Skull • 22 flat bones • Primary functions • encase/protect brain • provide frameworkfor head • Two parts: • Cranium (egg) • Facial region (mask)
Cranium of Infant • Still mostly cartilage; bones incompletely ossified • Fontanels (“little fountains”): fibrous membranes (a.k.a. soft spots) • Allows head compression for birth • Also allows for rapid brain growth in infants • Bones completely ossified by approximate age of 2
Cranial Sutures • Immovable joints • Joints are SUTURES • Serrated appearance • Allow tight fit among cranial bones • Occasionally visible on bald individuals
The Cranium • Encases brain • Includes 8 flat bones/know 6: • frontal (1) • occipital (1) • parietal (2) • temporal (2)
Frontal Bone • forms forehead • frontal eminence = wide, shallow bump on frontal bone, right on the forehead. • Orbits = sockets where eyeballs rest • glabella • superciliary crests: more prominent on males • temporal lines (anterior ends)
Frontal Eminence: wide, shallow bump on frontal bone, right on the forehead.
Superciliary arches/crests are more prominent on males than females.
Glabella Glabella = Slightly sunken area between superciliary crests.
Features of Occipital Bone • Occipital protuberance: small bump • on posterior base of cranium • Nuchal lines: horizontal ridges on either side of O. Protuberance • Foramen magnum: large hole at • base of skull through which • spinal cord exits the cranium
Parietal Bone • from L. paries (wall) • Bilateral • forms “roof” of skull • temporal line • parietal eminence (widest part of the skull)
Temporal Bone • Forms “temple” • bilateral • auditory meatus • mastoid process • zygomatic process (and zygomatic arch)
Auditory Meatus: an opening to the ear canal that leads to the inner ear.
Mastoid Process: a large bump posterior (behind) and inferior (below) the auditory meatus. • Can be felt behind and below the ear.
Zygomatic Bone (zygoma) • a.k.a. cheek bones • bilateral • part of zygomatic arch • widest point on the face
Zygomatic Arch Formed by Zygomatic bone + Zygomatic process of temporal bone
Zygomatic process of temporal bone Is widest point on the face
Nasal Bones • only in bridge of nose • often considered one bone, but is actually two, so… • bilateral • remainder of nose is cartilage and fat tissue
Maxilla(e) • Often considered one bone, but is actually two, so… • Bilateral (on both sides of the midline. The hands are bilateral.) • canine fossa (for cheek muscles • hard palate (roof of mouth) • dental arch with alveoli for upper teeth
Dental Arch • The superior portion of the 2 Maxillae that form the roof of the mouth
The Alveoli • Pockets in the Maxilla in which the roots of the upper teeth rest
Canine Fossa: a depression on the MAXILLA in which cheek muscles rest • Fossa is the Latin word for ditch or trench. • Fossa (anatomy) is an anatomical term that referring to a depression or hollow, in general, in a bone Canine Fossa
Mandible • a.k.a. jaw bone • Temporal-mandibular joint (T.M.J.) • Attaches to the temporal bone. • Only movable joint in the skill • angle of mandible • mental protuberance • alveoli for lower teeth
Temporal-mandibular joint • TMJ syndrome: • Pain or dysfunction of the temporal-mandibular joint is commonly referred to as "TMJ", • Problems involving the TMJs and the muscles, tendons, ligaments, blood vessels, and other tissues associated with them.
In anatomy, “mental” means “of the chin area.” The Mental Protuberance is a prominent surface landmark.
Mandible • a.k.a. jaw bone • Temporal-mandibular joint (T.M.J.) • Attaches to the temporal bone. • Only movable joint in the skill • angle of mandible • mental protuberance • alveoli for lower teeth
Sphenoid, Lacrimal, Vomer, Palatine, and Ethmoid Bones (not seen at surface)