460 



PRACTICAL ANATOMY. 



5. Blood-supply. Middle sacral and lateral sacral artery. 



6. Ligaments. Anterior sacro-coccygeal ligament, on the front of bodies ; 

 posterior sacro-coccygeal ligament, on posterior part of bodies ; supracornual 

 ligament, a prolongation of the supraspinous ligament ; intertransverse ligament, 

 analogous to the intertransverse ligaments of the true vertebrae ; intervertebral 

 substance of jelly-like cartilage. 



The Sacro- vertebral Articulation and its Ligaments : 



1. Class. Amphiarthrosis between the bodies of the vertebrae. 



2. Class. Diarthrosis between the articular processes. 



3. Subdivision. Arthrodia, because of a gliding movement. 



4. Osteological Units. Same as between two vertebrae. 



5. Subdivisional Parts. Same as in juxtaposition of vertebras. 



Lateral expanded portion 



Median longitudinal band 



Fic.. 332. POSTERIOR COMMON LIGAMENT OK THE SPINE. (Thoracic region.) 

 (Pedicles cut through, and posterior arches of vertebra removed.) 



6. Nerve-supply. Fourth and fifth lumbar and sympathetic. 



7. Blood-supply. Lateral sacral, last lumbar, ilio-lumbar. 



8. Special Name. Sacro-vertebral angle. 



9. Ligaments of Sacro-vertebral Articulation. (i) Prolongation down wan 

 of the ligaments of the vertebral column under the same name. They may be 

 modified to some extent to meet the particular demands of a special region ; for 

 this modification you can account philosophically : growth is the correlative of 

 function. (2) Sacro-lumbar ligament, triangular in shape. (3) Ilio-lumbar liga- 

 ment, triangular in shape. 



THE VERTEBRAL COLUMN AND ITS Lu; AMEN r>. 

 Of what is the vertebral column composed .' 

 Of thirty-three irregular bones, called vertebra.-. They arc classified as true 



