116 HUMAN ANATOMY. 



It transmits the following structures : 



(Esophagus, trachea, thoracic duct (on left side), lymphatic ves- 

 sels of right side of chest and of surface of liver, innominate artery 

 (right side), left common carotid artery, left subclavian artery, right 

 and left superior intercostal arteries, right and left internal mammary 

 arteries, thyroidea ima artery (if present), right and left inferior thy- 

 roid veins, right and left innominate veins, right and left phrenic nerves, 

 right and left pneumogastric nerves and their cardiac branches, left 

 recurrent laryngeal nerve, right and left first dorsal nerves, right and 

 left sympathetic nerves and their cardiac branches, apices of lungs and 

 pleurae, remains of thymus, and deep cervical fascia passing to peri- 

 cardium. 



The longus colli, sterno-hyoides, and sterno-thyroides on both 

 sides also pass through it. 



The inferior opening is formed by the last dorsal vertebra 

 behind, the last rib laterally, and the ensiform cartilage in front. 

 It is filled in by the diaphragm. 



The cavity of the thorax contains the following structures : 

 the heart and great vessels, trachea, bronchi, and lungs, azygos 

 and bronchial veins, internal mammary arteries, pneumogastric, 

 phrenic, and splanchnic nerves, thoracic duct, oesophagus, lym- 

 phatic vessels, and glands (vide mediastinum). 



SPINE AND PELVIS. 8 aero-vertebral articulation. In addi- 

 tion to those of the spine, given above, there are two ligaments 

 connecting the last lumbar vertebra with the sacrum: 



Lumbo-sacral ligament, arising from the transverse process 

 of the last lumbar vertebra, and inserted into the base of the 

 sacrum ; 



Ilio-lumbar ligament, arising from the apex of the trans- 

 verse process of the last lumbar vertebra, and inserted into the 

 crest of the ilium. The arteries are from last lumbar, ilio- 

 lumbar, and lateral sacral. The nerves are branches of fourth 

 and fifth lumbar and sympathetic. 



Sacro-iliac articulation, between the articular surfaces of 

 the sacrum and ilium, is an amphiarthrodial joint connected by 



The anterior sacro-iliac ligament, crossing between anterior 

 surfaces of the two bones; 



Posterior sacro-iliac ligament, the stronger, passes in dif- 

 ferent directions between the posterior surfaces of the two bones, 

 firmly binding them together. One of these, stronger than the 

 others, passes from the posterior superior spinous process to the 

 third sacral transverse process. It is called 



The oblique sacro-iliac ligament. 



The arteries are from gluteal, sacral, spinal, and ilio-lum- 

 bar; the nerves from lumbo-sacral and posterior sacral cords. 



