Vertebral Column

Vertebral Column

• Part of the axial skeleton

• Consists of 26 irregular bones

• 24 vertebrae, sacrum, coccyx

• Vertebral column divisions– Cervical C1-C7– Thoracic T1-T12– Lumbar L1-L5– Sacrum S1-S5(fused)

Spinal curvatures

• Cervical and lumbar curves are secondary curves

• Develop after birth

• Thoracic and sacral curves are primary curves

• Appear during fetal development

• Overall curve of the spine is S shaped

Vertebral Anatomy

• All vertebrae have a common structural plan• Structural features are:

– Vertebral body– Vertebral arch – Vertebral foramen– Pedicles– Lamina– Articular processes, superior and inferior– Spinous process

Cervical Vertebrae

• C1-C7• Smallest vertebrae• Small vertebral body• Triangular shaped vertebral foramen• Small spinous process that is usually notched at

the end – bifid process• ALL cervical vertebrae have a transverse

foramen• C1 is called the ATLAS• C2 is called the AXIS

C1- ATLAS

C2 - AXIS

C1-C2 Articulation

Thoracic Vertebrae

• T1-T12

• Larger vertebral body

• Oval vertebral foramen

• Spinous process projects posterocaudally

• T1-T8 vertebrae have superior and inferior costal facets for rib articulation

• T1-T10 have transverse costal facets for articulation of tubercles of the ribs

Lumbar Vertebrae

• L1-L5• Largest vertebrae• Large body• No articular facets on the body or

transverse processes• Triangular vertebral foramen• Short, flat spinous process• Weight bearing vertebrae

Sacrum

• Five fused sacral vertebrae• Fusion begins after puberty and is complete by

25-30 years of age• Curved dorsal surface• Special features

– Sacral canal– Median sacral crest– Sacral foramina– Lateral auricular surface to form the sacroiliac joint

Thoracic Cage

• Consists of the – Thoracic vertebrae– Ribs, 12 pair– Sternum– Ribs 1-7 are true ribs, vertebrosternal– Ribs 8-12 are false ribs, vertebrochondrial, do

not attach directly to the sternum– Ribs 11-12 are called floating ribs, NO

connection to sternum

Rib articulation to thoracic vertebrae

Features of a typical rib

Sternum

• Flat bone that forms the midline of the thoracic wall

• Three components– Manubrium – articulates with the clavicles and

costal cartilages of R1– Manubrium has the jugular notch on the

superior surface– Body of sternum, articulation of ribs 2-7– Xiphoid process