174 



THE ARTICULATIONS. 



tissue and want of elasticity. Those which are found around the margin of 

 articulations are termed peripheral, and those in their interior are designated 

 interosseous or interarticular ligaments. 



The peripheral ligaments are g^erallj composed of parallel fibres collected in 

 fasciculi, or spread out as membranes. In the first they are called funicular, or 

 riMon-shaped ; in the second, they are termed membraniform, or capsidar. The 

 funicular ligaments are short, round, or flattened bands, attached by their 

 extremities to the two bones they unite ; they are lined on their inner aspect 

 by the synovial capsule, and are covered .externally by tendons, aponeuroses, 

 muscles, vessels, or nerves. The capsular ligaments are often complete — that is 



Fig. 118. 



WHITE OR NON-ELASTIC FIBBOUS 



TISSUE. 



YELLOW OR ELASTIC FIBROUS TISSUE, 

 THE LIGAMENTUM NUCH^E. 



to say, they envelop the whole articulation like a sack. At other times they are 

 incomplete, and then they are simple membranes, binding together the different 

 funicular ligaments of a joint. 



The interosseous ligaments — less numerous than the preceding — are often formed 

 of interlacing fibres ; they are always funicular, and fixed by their extremities 

 into excavations in the centre of articular surfaces. 



J. Hhe yellow ligaments are 2k[[ perijyheral, funicular, or 7nembranous, and enjoy 

 a marked degree of elasticity, which permits them mechanically to bring back to 

 their usual position the bony levers that have been momentarily displaced. These 

 ligaments, which are powerful auxiliaries to the muscular forces, give permanent 

 equilibrium to the weight in certain parts of the body, which incessantly tend to 

 fall to the ground ; for instance, the cervical ligament of Solipeds and large 

 Ruminants. The ligaments are always assisted in their action by atmospheric 

 pressure, which is exerted over all the surface of the body ; and also frequently by 

 the tendons and aponeurosis of muscles, and even by the muscles themselves, 

 when they pass over an articulation or are inserted in its vicinity. In several 

 regions the ligaments are more or less confounded w^ith tendons or aponeiu-oses — 

 as in the anterior extensor tendon of the phalanges and superior sesamoid liga- 

 ment, the ligaments of the femoro-tibial articulation, and the aponeuroses of the 

 posterior portion of the superficial gluteal muscle. 



Synovial Capsules. — These are very thin membranes of a serous character, 

 intended to secrete the synovia. They are composed of two layers : a deep, 

 formed by fasciculi of connective tissue ; the other, superficial, formed by an 



