490 



DISSECTION OF THE THORAX. 



and costal 

 cartilages. 



To see the 

 costo-verte- 

 bral liga- 

 ments, 



Ligaments 

 of head of 

 rib are 



anterior or 

 stellate 



and iriterar- 

 ticular, 



with syno- 

 vial sacs. 



Costo- 

 trans verse 



ligaments : 



The costal cartilages are connected to the sternum and to one 

 another by synovial joints and ligaments. 



Dissection. For the purpose of examining the ligaments between 

 the ribs and the vertebrae, take the piece of the spinal column with 

 the third, fourth, fifth, and sixth ribs attached to it. After 

 removing the intercostal and other muscles, and the loose tissue 

 from the surface of the bones, the student will be able to define, as 

 below, the ligaments passing from the head and neck of the rib to 



the bodies and transverse processes 

 of the vertebrae. 



The ligaments attaching the costal 

 cartilages to the sternum are to be 

 dissected on the part of the thorax 

 which was removed in opening the 

 cavity. 



LIGAMENTS OF THE HEAD OF THE 

 RIB. Where the head of the rib is 

 received into a hollow in the bodies 

 of two contiguous vertebrae, there 

 are two ligaments to the articula- 

 tion anterior costo-central, and 

 interarticular, with two synovial sacs. 

 The anterior costo-central or stellate 

 ligament (fig. 177, 3 ) is composed 

 of radiating fibres, which pass from 

 the head of the rib to the two 

 vertebral bodies forming the arti- 

 cular cavity, and to the disc 

 between them. Where the rib is 

 in contact only with one vertebra, 

 i.e., in the first, eleventh and 

 twelfth, a few fibres ascend to the 

 vertebra immediately above. 



The interarticular ligament will be 

 seen when the stellate is divided. 

 It is a very short thin band, which 

 is attached on one side to the ridge 

 separating the two articular surfaces 

 on the head of the rib, and on the other to the intervertebral disc. 

 In the joints of the first, eleventh, and twelfth ribs, where the 

 head is not in contact with the intervertebral substance, it is 

 absent. 



Synovial sacs. There are usually two synovial cavities in the 

 costo-central articulation, one on each side of the interarticular liga- 

 ment ; but in the three joints before mentioned (1st, llth, 12th) 

 there is but one. The special features of these joints should be 

 verified at this time. 



LIGAMENTS OF THE NECK AND TUBEROSITY. Three ligaments 

 pass from the neck and tuberosity of the rib to the transverse 

 processes of the two vertebrae with which the head is connected ; 



FIG. 177. LIGAMENTS OP THE RIBS 

 AND VERTEBRJ3 (BOURGERY). 



1. Anterior ligament of the 

 bodies of the vertebrae. 



2. Short lateral fibres uniting 

 the bodies. 



3. Stellate ligament. 



4. Superior costo - transverse 

 ligament. 



5. Interspinous ligament. 



