The Vertebrae

Structure of typical Vertebrae

Consists of Vertebral body and Vertebral arch,extending from vertebral arch there are number of processes.these process act as muscle attachments and articulation with  adjacent bone.

Vertebral body-weight bearing part
                        linked to adjacent vertebral bodies by inter-vertebral discs and ligaments
                        size increases inferiorly (because weight supported increases)
                     
Vertebral arch-forms vertebral foramen(forms lateral and posterior parts)

Vertebral canal-vertebral foramina of all the vertebra together form vertebral canal.

                   Contain and protects the spinal cord.

                   Superiorly continuous through foramen magnam

vertebral arch consists two components

• pedicale
• laminae

pedicles-bony pillars which attach vertebral arch to vertebral body

laminae-sheet of bone etend from each pedicle to meet in midline

forms roof of vertebral arch

spinous process-project posteriorly and inferiorly 

                         junction of the two laminae

                         site for muscle,ligament attachment

transverse process-posterolaterally 

                             junction of the pedicle and lamina(each side)

                             site for articulation with ribs(in the thoracic region)

superior and inferior articular processes-articulate with inferior and superior articular processes(adjacent                                     vertebrae) 

inter vertebral foramina-between vertebral body and the origin of the articular processes

                                    each pedical is notched on its superior and inferior surfaces

                                    formed by superior and inferior vertebral notches

       

	Cervical	Thorasic	Lumbar
Size	small	larger	largest
Foramina	Cervical- one vertebral and two transverse	Thoracic- one vertebral	Lumbar- one vertebral
Spinous processes	Cervical- slender and often bifid (C2-C6)	Thoracic- long and fairly thick (most project inferiorly)	Lumbar- short and blunt (project posteriorly rather than inferiorly)
Transverse processes	Cervical- small	Thoracic-fairly large	Lumbar- large and blunt
Articular facets for ribs	Cervical- absent	Thoracic- present	Lumbar- absent
Direction of articular facets (superior)	Cervical- posterosuperior	Thoracic- posterolateral	Lumbar- medial
Direction of articular facets (inferior)	Cervical- anteroinferior	Thoracic- anteromedial	Lumbar- lateral
Size of intervertebral discs	Cervical- Thick relative to size of vertebral bodies	Thoracic- Thin relative to vertebral bodies	Lumbar- Massive

*Sacral-consists of five rudimentary vertebrae

Triangular shapearticulate with lamber 5 vertebrae

Articulate with illium

Form Sacroiliac joint

Inferiorly articulate with coccyx

Anterior edge of the base the promontory protrudes into the pelvic cavity

Vertebral foramina are present on each side

series of foramina for the passage of nerves