BONES OF THE NECK.pptx

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1. BONES OF THE NECK 1

2. CERVICAL VERTEBRAE HYOID BONE 2

3. CERVICAL VERTEBRAE Smallest of the vertebrae Lies between the cranium and thoracic vertebrae Consists of 7 distinct vertebrae- C1-C7 Has 3 main characteristic features Triangular vertebral foramen Bifid spinous process Transverse foramina 3

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5. Typical cervical vertebrae Large transverse foramina that transmit the vertebral artery Short and bifid spinous process C3-C6 Atypical cervical vertebrae C1,C2 and C7 C7 is also called vertebra prominens because of its prominent spine C7 is atypical in that its long spine is not bifid but ends in a rounded tubercle and the transverse foramen does not transmit the vertebral artery 5

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7. C1 vertebra Also known as Atlas Has no vertebral body Has no spinous process Has lateral masses connected by an anterior and posterior arch that serve as body for weight bearing Anterior arch contains a facet for articulation with the dens of the axis 7

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10. C2 Vertebra Also known as Axis Presence of odontoid process (dens) that extends superiorly from the anterior portion of the vertebra The dens articulates with the anterior arch of the atlas creating the medial atlanto -axial joint 10

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13. CLINICAL RELEVANCE Jefferson fracture of atlas Compression of the lateral masses of the atlas due to a vertical fall onto an extended neck Causes them to be driven apart, fracturing one or both anterior/posterior arches Transverse ligament of the atlas may also be ruptured if the fall occurs with enough force 13

14. HYOID BONE U-shaped bone located in the anterior neck. Lies at the base of the mandible at approx. C3 vertebra Acts as site of attachment for the anterior neck muscles 14

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16. STRUCTURE OF HYOID BONE Body Central part Has anterior convex and posterior concave surface Greater horn Projects from each end of the body posteriolaterally Lesser horn Arises from the superior aspect of the hyoid bone near the origin of the greater horn Projects superioposteriorly toward the styloid process 16

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18. MUSCULAR ATTACHMENTS Unique bone- it does not articulate with any other bones. Suspended in place by the muscles and ligaments that attach to it Muscular attachments include; suprahyoid muscles, infrahyoid muscles, muscle from the pharynx and oral cavity. 18

19. LIGAMENT ATTACHMENTS Stylohoid ligament From styloid process of temporal bone to lesser horn of the hyoid bone T hyrohyoid membrane From superior border of the thyroid cartilage to posterior surface of hyoid bone and greater horns Hyoepiglottic ligament Connects the hyoid bone to anterior aspect of the epiglottis 19

20. CLINICAL RELEVANCE Fracture of hyoid bone Relatively rare Well protected by the mandible and cervical vertebrae Characteristically associated with strangulation; therefore a significant post-mortem finding Can also occur as a result of trauma Clinical features include; pain on speaking, odynophagia and dsypnoea 20

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