492 



DISSECTION OF THE THORAX. 



Costo 



xiphoid 



ligament. 



First carti- 



Cartilages 

 with one 

 another. 



Two sets of 

 ligaments 

 unite the 

 vertebrae. 



How to see 

 the several 

 ligaments. 



ligament like that to the head of the rib which joins the cartilage 

 between the pieces of the sternum ; and the sy no vial sac is double. 

 Similar bands are sometimes present in one or two of the 

 succeeding joints. 



A special band of fibres passes from the cartilage of the seventh 

 rib to the ensiform process, and is named costo-xiphoid ligament. 



The cartilage of the first rib adheres directly to the sternum, 

 without forming any joint. 



INTERCHONDRAL ARTICULATIONS. The cartilages of the ribs 

 from the sixth to the ninth articulate together by means of broad 

 processes on their adjacent edges, which are connected by synovial 

 joints. Each joint is surrounded by a short capsule, and is sup- 

 ported in front by strong fibres of 

 the anterior intercostal aponeurosis. 

 The ends of the eighth, ninth, and 

 tenth cartilages are united each to 

 the cartilage above by bands of 

 fibrous tissue. 



Movements. There is only a 

 limited degree of movement in 

 the chondro - sternal and inter- 

 chondral articulations, the carti- 

 lages being elevated with the ribs 

 in inspiration, and sinking in 

 expiration. 



ARTICULATION OF THE STER- 

 NUM. The manubrium and body 

 of the sternum are united by a 

 piece of cartilage, with anterior 

 and posterior longitudinal fibres. 

 In some cases there is a cavity 

 resulting from the absorption of 

 the central portion of the carti- 

 lage. There is no appreciable 



movement between the pieces of the sternum, but the articulation 

 aids in giving elasticity to the front of the chest. 



ARTICULATIONS OF THE VERTEBRAE. The vertebrae are united 

 together by two sets of ligaments, one for the bodies, and the other 

 for the arches and processes. 



Along the spinal column the ligaments have a general resem- 

 blance, and one description will suffice, except for those between 

 the first two vertebrae and the head and those of the pelvis, which 

 are described in the head and neck and abdomen respectively. 



Dissection. After the articulations of the ribs have been 

 examined, the same piece of the spinal column will serve for the 

 preparation of the ligaments of the bodies of the vertebrae. The 

 anterior ligament of the bodies will be defined with very little 

 trouble, by removing the areolar tissue. 



The spinal canal is assumed to have been opened in the examina- 

 tion of the spinal cord, and the posterior ligament of the bodies of 



FIG. 178. 



a. Anterior common ligament of 

 the bodies of the vertebrae. 



b. Lateral short fibres. 



