Comparison of Structural Features of Cervical,Thoracic,Lumbar,sacral Vertebrae

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

Cervical(C4)

Thoracic(T6)

Lumbar(L3)

Sacrum and Coccyx

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)

Skeletal system of the man

Skeletal system consists of 

• bones
• cartilage 
• connective ligaments

Chemical composition of bones

•    Water 50%

•     Inorganic component 21.85% for hardness and rigidity

      Calcium phosphate, calcium   carbonate,magnesium, fluorine, sulphur

•     organic component    28.5% for strength and flexibility

     collagen Type 1 glycosaminoglycans,   proteoglycans, glycoproteins