62 TEXT-BOOK OF PHYSIOLOGY. 



regions extension and flexion are freely permitted, though the former 

 is greater in the cervical, the latter in the lumbar region, especially 

 between the fourth and fifth vertebrae. Lateral flexion takes place 

 in all portions of the column, but is particularly marked in the cer- 

 vical region. A rotatory movement of the column as a whole takes 

 place through an angle of about twenty-eight degrees. This is most 

 evident in the lower cervical and dorsal regions. 



The skeleton may, therefore, be regarded as a highly developed 

 framework, which determines not only the form of the body, and 

 affords support and protection to the various softer organs and 

 tissues, but also, through the mobility of its joints, permits of a great 

 variety of complicated movements. 



