34 



THE SKELETON OF THE HORSE 



Spinous 

 process 



Vertebral foramen 



Foramen 

 transver- 

 sarium 



Trans- 

 verse 

 process 



Head 



Fig. 9. — Sixth Ceevical Vehtebra of Horse; Anterior View. 



THE CERVICAL VERTEBRS: 



The cervical vertebrae (Vertebrae cervicales) are seven in number. 

 The first and second cervical vertebrae are highly modified in conformity with 



the special functions of support 

 and movements of the head. 

 The sixth and seventh present 

 special characters, but do not 

 differ greatly from the type. 

 With the exception of the first, 

 they are quadrangular, mass- 

 ive, and longer than the ver- 

 tebrae of other regions; they 

 decrease in length from the 

 second to the last. The third, 

 fotirth, and fifth have the fol- 

 lowing characters: 



1. The body is long as 

 compared with those of other 

 vertebrae. The ventral surface 

 presents a median ventral 

 spine, which becomes more 

 prominent as it is traced back- 

 ward, and is tuberculate at its 

 posterior end; it separates two 

 concave areas. The dorsal sur- 

 face has a flat central area which is narrow in the middle of the vertebrae, and wide 

 at either end; it gives attachment to the dorsal longitudinal ligament. On either 

 side of this area there is a groove which lodges the longitudinal spinal vein. These 

 lateral grooves are connected about the middle of the surface by a transverse furrow,, 

 in which there are several for- 

 amina through which veins 

 emerge from the spongy sub- 

 stance of the body. The an- 

 terior extremity or head (Ca- 

 put vertebrae) has an oval 

 articular surface which faces 

 forward and downward; it is 

 strongly convex, and wider 

 above than below. The pos- 

 terior extremity is larger and 

 has a nearly circular cotjdoid 

 cavity (Fossa vertebrae). 



2. The arch is large and 

 strong. It is perforated on 

 either side by a foramen which 

 communicates with the for- 

 amen transversarium. The 

 verteljral notches are large. 



3. The articular processes 

 are large. Their articular sur- 

 faces are extensive, oval in outline, and slightly concave; the anterior ones are 

 directed dorso-medially ; the posterior, ventro-laterally. The remaining surface is 

 mainly roughened for ligamentous and muscular attachment. A crest connects 



Spinous process 

 Vertebral 



Articular 

 process 



Ventral spine 

 Fig. 10. — Seventh Cervical Vertebra of Horse; Anterior View. 



