282 



FASCLE AND MUSCLES OF THE HORSE 



Origin. — The transverse processes of the thoracic vertebrae. 



Insertion.— The lateral surfaces of the upper ends of the ribs posterior to the 

 vertebral origin. 



Action. — To draw the ribs forward in inspiration. 



Structure. — Arising by tendinous fibers, each muscle passes backward and out- 

 ward and expands at its insertion. Some fibers pass over one rib and are inserted 



iSei'cnth ceri'ical vertebra-" 

 First thoracic rcrlvbra- 



Sectioii of \inpula 



iinsn'rsalcs 



Intercostal f 

 7ierve6 I. 



Retractor cobtce 



Intertrnnsrersi ligaments , 

 Ilio-lumbar ligomtnl / 



,W liuitorcs costarum 



External 

 intercostal 

 J muscles 



Lateral harder of lon- 

 gissimus dorsi 



Tuber coxce 



Fig. 273. — Deep Dissection' of Dorsal and Lumbar Regions of Horse; Dorsal View. (After Schmaltz, Atlas 



d. Anat. d. Pferdes.) 



on a succeeding one. At the beginning and end of the series the muscle cannot be 

 distinguished from the external intercostal, of which it is in reality only a specially 

 developed part. 



Relations. — Superficially, the longissimus dorsi; deeply, the ribs, internal in- 

 tercostal muscles, and the intercostal vessels and nerves. 



Blood-supply. — Intercostal arteries. 



