SPECIAL ANATOMY. 



lations. They are named Menisci, ^uv. from their Biconcavity. The carti- 

 lage may waste away by attrition. 



3. Fibrous cartilages of the osseous joints, are generally disc-shaped, united 

 closely with the Periosteum ; for example, symphysis pubis, or annular labra 

 glenoidea attached to the borders of the articular fossae. 



111. Connections of the Vertebras with each other, Articulatio 

 vertebrarum. 



a. The vertebral bodies are united with each other by a close 

 articulation, amphiarthrosis. The articular surfaces which are 

 the superior and inferior surfaces of each vertebral body, are 

 rather concave, do not immediately touch, but lie upon one another 

 by means of: 



1. The ligg. (cartilagines) intervertebralia, twenty three strong lenticular discs, 

 consisting of concentric fibrous rings which, closer in the periphery, are sepa- 

 rated towards the centre, the interspaces being filled by a yellow jelly, which, 

 in the central point, becomes hardened into an elastic osseous nucleus. Their 

 vertical diameter varies; it may, for example, diminish after standing long 

 in the erect posture. In youth the gelatinous masses are softer and whiter 

 than in old age, and on this account the vertebral column is less moveable in 

 the latter than in the former. The vertebral bodies are further surrounded 

 with a fibrous sheath, the 



2. Lig. longitudinale anterius, on the anterior surface, from the Tuberculum 

 atlantis anticum to the upper part of the os Sacrum; above narrow, below 

 broad; white, membranous, thicker on the dorsal than upon the cervical and 

 lumbar vertebra;; consists of two lateral portions, which are separated in the 

 centre by a series of openings, for vessels. Below it mingles with the fibres 

 of the crura of the Diaphragm and the Aponeurosis of the m. psoas ; above 

 with the tendons of the m. long, colli and rectus. 



3. Lig. longilud. postcrius, on the posterior surface, on the anterior of the 

 Canal, spinalis, thicker and narrower than 2, commences upon the internal 

 surface of the pars basil, occip.: the superior portion, from the third cervical 

 vertebra, is particularly distinguished as apparatus ligamentosus, terminates in 

 the Canal. Sacralis. The posterior surface is connected by processes with 

 Dura Mater, the anterior with the ligam. intervertebralia. On the borders, 

 passes sinus venosi, in the centre, between the ligament and the vertebral body, 

 the venue vertebrales. It extends, like the anterior, upon the intervertebral car- 

 tilages, and attaches itself firmly to them. 



b. Connection of the Processus obliqui, Jlrtlirodia. The 

 articular surfaces are covered with cartilage, provided with a 

 8-ynovial sac, and united together by ligg. capsularia. 



c. Ligaments of the Vertebral arches : 



Ligg. flava s. inter crur alia, filling up the intervals between the arches, are, 

 really, higher than these, thicker in the lumbar vertebrae, thickest in the region 

 of the Proc. spinosi. Attachment: to the inferior and superior border of two 

 vertebra?, as the one lies upon the other. Anterior surface smooth, separated 

 from the Dura Mater by areolar tissue and Vv. spinales. Structure: thick, 

 vertical, elastic but strong fibres. Use : to assist the Dorsal muscles in main- 

 taining the erect posture of the body. 



