102 SPECIAL ANATOMY. 



4. Lig. transversarium internum, rhombic, from the inferior border of the 

 proc. trans, of the vertebra next above to the superior border of the Collum, 

 wanting on the twelfth rib ; divides the posterior and anterior branches of the 

 Intercostal nerves. 



5. Lig. transversarium intern., triangular, weak, descends from the root of 

 the proc. transvers. of the vertebra next above to the posterior surface of the 

 collum costcB, close to the capitulum; it is wanting on the first, eleventh, and 

 twelfth ribs. 



116. II. The ribs with the sternum, articulatio sterno- cost alis, 

 Amphiarthrosis. The cartilages of the ribs which are firmly con- 

 nected with the bone, and possess no farther external means of 

 union than the common Periosteum, Perichondrium, are inti- 

 mately attached in the incisura. costal, sterni by Synovial cap- 

 sules and stellate ligaments, from the second to the seventh rib. 

 The fifth to the ninth ribs have, at their place of contact, delicate 

 synovial capsules. The first rib cartilage is, generally, closely 

 united with the sternum. 



Ligaments: 1. Lig. interarticulare, of the second to the fifth ribs, divides 

 the double synovial capsules. 



2. Lig. radiatum externum, proceeds from a true rib cartilage of one side to 

 the one next above of the other, crosses also upon the centre of the Sternum, 

 and loses itself in the Periosteum and the tendinous expansion of the great 

 pectoral muscles. In a like manner is arranged the less strong Lig. rad. intern. 

 upon the posterior surface of the Sternum. 



3. Ligg. coruscantia, brilliant bundles of fibres between the third to the 

 tenth rib cartilages, to fill up the spaces between the cartilages of the ribs. 

 Vide m. intercostales. 



4. Ligg. processus ensiformis, proceed from the inferior border of the sixth and 

 seventh rib cartilages over the centre of the ensiform process and attach it to 

 them. 



5. Membrana sterni propria, covers the external and internal surface of the 

 Sternum, and consists of the fibres of Periosteum crossing each other. 



Movements of the chest. 



1. Expansion, upon inspiration, by elevation of the ribs, whereby the an- 

 terior extremities of the ribs move forwards, the lateral outwards, and the 

 diameter of the thorax is increased from before to behind and transversely. 

 In forcible inspiration the Sternum also is elevated. The first rib remains 

 immoveable. 



2. Contraction, upon expiration, depends upon the falling back of the ribs 

 and these parts, from their weight, and the elasticity of the cartilage, as well 

 as in consequence of the direct action of the expiratory muscles. 



117. Connections of the Pelvis. 



a. The Ossa coxarum with each other. Symphysis ossium 

 pubis. Pubic symphysis with : 



1. Lig. (s. cartilago) interosseum pubis, a prismatic, fibro-cartilage, as on the 

 bodies of the vertebrae, half an inch broad in front, covered by crossed fibres 

 and by Lig. pubis, s. arcualtim, superius, transversely from one tuberculum pubis 

 to the other. 



