Axial Skeleton Essay

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bones of the axial skeleton, and specify their functions. Axial Skeleton SKULL AND ASSOCIATES VERTEBRAE THORACIC CAGE FACE CRANIUM ASSOC. BONES 24 vertebrae The sacrum The coccyx Sternum (1) Ribs (24) Inferior nasal concha (2) Lacrimal bones (2) Mandible(1) Maxilla (2) Nasal bones (2) Palatine (bones (2) Vomer(1) Zygomatic bones (2) Ethmoid (1) Frontal (1) Occipital Bone(1) Parietal Bones(2) Sphenoid Bone(1) Temporal Bones(2) Hyoid bone (1) Protect and support entrances to digestive and respiratory tracts Form the braincase, or cranium Supports the head, neck, and trunk Forms protective cage around heart, lungs, blood vessels. Supports shoulder girdles and upper limbs. Contains true ribs, false ribs and floating ribs. 2. Identify…show more content…
Describe the structure and functions of the orbital complex, nasal complex, and paranasal sinuses. The eye sockets (orbits) which contain the eyes are formed of portions of 7 cranial and facial bones called the orbital complex: the frontal bone (roof), maxillary bone (floor), maxillary, lacrimal and ethmoid bones , sphenoid and palatine bones The bones of the nasal cavities and paranasal sinuses form the nasal complex, these are: The frontal bone, sphenoid, ethmoid ,maxillary, lacrimal, inferior nasal conchae and nasal bones. The paranasal sinuses are air-filled chambers connected to the nasal cavities. Paranasal sinuses lighten skull bones and provide extensive areas of mucous epithelium, they flush the nasal cavities with mucus and protects the entrance of the respiratory tract. Cilia sweep the mucus and trapped particles back into the throat, where it is swallowed. 4. Describe the key structural differences among the skulls of infants, children, and adults. During development, the skull grows rapidly and has many ossification centers. At birth there are two frontal bones, four occipital bones and several sphenoid and temporal elements. The bones are connected by four areas of fibrous connective tissue (fontanels), these which allow the skull to flex during…show more content…
The rib articulates with the vertebral column at the head. From the head, a short neck leads to the tubercle, a small elevation that projects dorsally. The inferior portion contains an articular facet that contacts the transverse process of the thoracic vertebra. The heads of ribs 2–9 articulate with costal facets on two adjacent vertebrae. Their tubercular facets articulate with the transverse costal facets of the inferior member of the vertebral pair. Ribs 11 and 12, which originate at T11 and T12, do not have tubercular facets and do not contact the transverse processes. Because of the flexibility of the ribs, their movements during breathing changes the position of the sternum. This lowers the ribs and pulls the sternum inward, and raising the ribs moves it outward. As a result, movements of the ribs change both the width and the depth of the thoracic cage, decreasing or increasing its volume accordingly as we breathe out or in. The sternum has three parts: The broad, triangular manubrium articulates with the clavicles (collarbones) and the cartilages of the first pair of ribs. The jugular notch, located between the clavicular articulations, is a shallow indentation on the superior surface of the manubrium. 2. The tongue-shaped body attaches to the inferior surface of the manubrium and extends inferiorly along the midline.

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