PELVIS MINOR 471 



bind the several segments of the vertebral column together. 

 Two additional ligaments, on each side, viz., the lumbo-sacral 

 and the ilio-lumbar, must now be examined. 



The lumbo-sacral ligaments are the representatives of the 

 anterior costo- transverse ligaments. Each is a strong, 

 triangular, fibrous band, attached by its apex to the tip and 

 lower border of the transverse process of the last lumbar 

 vertebra. Expanding as it proceeds downwards, it is fixed 

 below to the posterior part of the base of the sacrum, where 

 some of its fibres intermingle with those of the sacro-iliac 

 ligaments. 



Ligamenta Iliolumbalia. Each ilio-lumbar ligament may be 

 considered a thickened and specially developed part of the 

 anterior lamella of the lumbar fascia of the corresponding 

 side, for it lies in the same plane as the fascia and is directly 

 continuous with it. It is triangular in shape, and is fixed by 

 its apex to the tip of the transverse process of the last lumbar 

 vertebra. Proceeding horizontally and laterally, it is inserted 

 into the internal lip of the iliac crest, at the posterior part of 

 the iliac fossa. 



The synchondrosis between the body of the last lumbar 

 vertebra and the base of the sacrum corresponds, in every 

 respect, to the similar articulations between the bodies of 

 the vertebrae above. The opposed bony surfaces are each 

 coated with a thin layer of hyaline cartilage, and are firmly 

 united by an intervening disc of fibro-cartilage, which is dense 

 and laminated externally, but soft and pulpy towards the centre. 

 The dissector should note that the disc is the thickest of the 

 series, and further, that it is wedge-shaped, being thicker in 

 front than behind. 



Sacro-coccygeal Articulations. The sacro-coccygeal articu- 

 lations are (i) a synchondrosis between the bodies of the 

 last sacral and the first coccygeal vertebra, and (2) a pair of 

 syndesmoses between the sacral and coccygeal cornua. In 

 the synchondrosis between the bodies of the last sacral and 

 the first coccygeal vertebra each of the articulating surfaces 

 is covered with a thin cartilaginous plate, and the cartilage 

 plates are united by a disc of fibro-cartilage. The joint is 

 strengthened in front by an anterior ligament, which extends 

 downwards from the front of the sacrum to the anterior aspect 

 of the coccyx, and by a posterior ligament, which, attached 

 above to the posterior border of the lower aperture of the 



