LECTURE II 

 OSTEOLOGY 



Spinal column.— This consists of about 55 pieces, called ver- 

 tebrie. There are 7 cervical, 18 dorsal, 6 lumbar, 5 sacral, 15 

 to 21 coccygeal. 



There are certain general characteristics possessed by all ver- 

 tebra, regardless of location in the spinal column ; for instance, 

 each vertebra has a body, arch, and spinal canal. 



The hodij, convex in front and concave behind, is below the 

 spinal canal. The head of the body of each vertebra is rounded 

 and fits perfectly into the cavity of the rear end of the preced- 

 ing vertebra. Between each pair is considerable cartilage, which 

 serves the purpose of an elastic pad. 



The arch incloses the sides and top of the spinal canal. (1) 

 The transverse processes are the portions which project hori- 

 zontally on each side from the arch. 

 (2) The superior process projects up- 

 ward from the top of the arch. (3) 

 The articular processes are four in 

 number : two in front, and two behind. 

 The former articulate with the rear 

 articular processes of the preceding y\g. 7.— Typical Ceevical 

 vertebra, and the latter with the front Vertebra. 



processes of the succeeding. ^- Head of the body; B, 



. mi p 1 transverse process; C, ar- 



CervicaJ vertebrae.— The framework ticuiar process; B, supe- 

 consists of 7 cervical vertebne, all rior spiuous process, 

 agreeing in certain general characters. 



The body is long, thick, and has an inferior spine projecting 

 downward from its under surface. The superior processes are 

 long from before to behind, and together form a long rough line. 

 The transverse processes are also long from before to behind. In 

 these characteristics the cervical vertebrae differ radically from 

 the others. 



Special cervical vertchrcv. — There are certain cervical verte- 



7 



