Skeletal System Axial Vertebrae Copyright 2009 Pearson Education

A Typical Vertebrae, Superior View Not all vertebrae look alike, but they do share certain structures: 1. Body: weight bearing portion, faces anteriorly 2. Vertebral arch: composed of lamina and pedicle Figure 5. 17 Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

A Typical Vertebrae, Superior View 3. Vertebral foramen: canal in which the spinal cord passes 4. Transverse process: lateral extensions (2) 5. Spinous process: single projection pointing posterior 6. Articulate processes: site of vertebral joints Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 5. 17

Regional Characteristics of Vertebrae Cervical Vertebrae (7) Atlas: First vertebra (no body) Allows “yes” nod, by holding the occipital condyles (see green arrow) Axis: 2 nd vertebra (small body) Allows “no” pivot where the dens articulates to the atlas Figure 5. 18 a Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Regional Characteristics of Vertebrae Looking for ideas on remembering thoracic? Foramen for the carotid artery 90 degree forms an “L” Figure 5. 18 b Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Sacrum and Coccyx § Sacrum § Formed by the fusion vertebrae § Forms posterior wall of pelvis § Articulates to the hip § Coccyx § Formed from the fusion of vertebrae § “Tailbone” Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

The Bony Thorax (AKA: Thoracic Cage) § Forms a cage to protect major thoracic organs § Consists of three parts § Sternum § Ribs § Thoracic vertebrae Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Boney Thorax (AKA: Thoracic Cage) Sternum: (composed of 3 bones) • manubrium • Body

Boney Thorax (AKA: Thoracic Cage) Ribs: 12 pairs 1 st seven “true” ribs, attach to sternum 8 -10 “false” ribs indirectly attached to sternum or not attached 11 -12 AKA floating ribs Figure 5. 20 a Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings