Describe how the following vertebrae are adapted to their functions.

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 a)  Atlas
-Has  a  wide  neural  canal;  to  accommodate  the  large  spinal  cord  at  the  neck  region; 
-has large/broad  wing-like  cervical  ribs;  to  increase  the  surface  area  for  attachment  of  the  neck muscles; 
-has  facets  on  the  anterior  side;  for  articulation  with  the  occipital  condyles  of  the  skull; allowing  up  and  down  movement/nodding  of  the  head; 
-has  posterior  facets  for  articulation  with the  anterior  facets  of  the  axis;  forming  a  joint  that  allows  sideways  movement  of  the  head;

 b)  Axis
-Has  a  broad  centrum;  that  projects  to  form  the  odontoid  process;  for  articulation  with  the  neural canal  of  the  atlas;  a  joint  that  allows  turning  of  the  head;
- has  a  large  and  broad/flattened  neural spine;  and  flat  cervical  ribs;  to  increase  the  surface  area  for  attachment  of  neck  muscles;
 c)  Lumbar
- Has  many  transverse  processes;  and  additional  projections  (metapophyses,  hypapophyses, anapophyses);  to  offer  a  large  surface  area  for  attachment  of  abdominal  muscles;
- broad  neural canal;  to  allow  passage  of  the  large  spinal  cord  at  the  upper  abdominal  area; 
-large/thick centrum;  to  support  the  weight  of  the  body;  and  withstand  strains/upthrust  force  due  to movement;
 d)  Thoracic
- Long/elongated  neural  spine;  to  offer  a  large  surface  area  for  attachment  of  the  large  back muscles;
- have  a  large  centrum  and  neural  canal;  to  offer  support  to  the  thoracic  cage;
- has tubercular  facet  on  the  transverse  processes;  to  articulate  with  the  tuberculum  of  the  ribs;  while the  capitular  demifacets  on  the  centrum;  articulates  with  the  capitula  of  the  ribs;
- together  with the  ribs  and  the  sternum  form  the  thoracic/rib  cage;  for  protection  of  heart  and  lungs;  and  for breathing  process;  Max.  20  mks

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