256 THE ARTICULATIONS OR JOINTS. 
lumbar, and weakest in the dorsal region. ach consists of layers of obliquely 
interlacing fibres which spring from near the tips of the two adjacent spines and 
radiate to their opposing 
Pedicle of margins. In the antero- 
_- vertebra One ; : 
_7~ divided posterior direction they 
extend from the base to 
the tip of the spinous 
process. 
The supraspinous liga- 
ments (ligg. supra- 
spinalia, Fig. 198) consist 
_ Tamina of of longitudinal bands of 
fibres of varying lengths. 
They extend from spine 
tospine, beingattached to 
their tips,andare situated 
superficial to, although 
in continuity with, the 
interspinous ligaments. 
In the cervical region 
this series of ligaments 
Transverse ig extensively developed, 
~~, where they project back- 
wards from the spinous 
processes between the 
muscles of the two sides 
of the neck in the form 
Fic. 201.—LIGAMENTA SUBFLAVA AS SEEN FROM THE FRONT AFTER RE- of an elastic partition 
MOVAL OF THE BODIES OF THE VERTEBR& BY SAWING THROUGH THE me 
called the ° ligamentum 
PEDIOLES, 
nuche. 
The antero-posterior extent of the hgamentum nuche increases as 1t approaches 
the occiput, where it is attached to the occipital crest from the external occipital 
protuberance to the posterior border of the foramen magnum. Its posterior margin 
is free, and extends from the external occipital protuberance to the spine of the 
vertebra prominens. 
Between the transverse processes there are intertransverse ligaments (lige. inter- 
transversaria), which consist of vertical fibres extending from the postero-inferior 
aspect of one transverse process to the superior margin of that next below. These 
ligaments are generally absent from the cervical and upper dorsal regions. | 
Sacro-coccygeal Joint.—The last piece of the sacrum is joined to the first 
piece of the coccyx by an intervertebral disc, and the junction is rendered 
more secure by the presence of certain strong ligaments. An anterior ligament 
(lig. sacro-coccygeum anterius), continuous with the anterior common ligament, is 
placed in front. A posterior ligament (lig. sacro-coceygeum posterius), which 
stretches downwards from the sharp border of the lower opening of the sacral 
Ligamentum 
flavum or. 
subflavum 
Ligamentum oR 
flavum or / 
as 
subflavuin {~i; 
Mi 
canal, strengthens the joint behind. A lateral ligament (lig. sacro-coccygeum > 
laterale) supports the joint on each side, whilst strong bands pass between the 
cornua of the two bones and constitute the interarticular ligaments. 
Inter-coccygeal Joints.—So long as they remain separate, the different pieces 
of the coceyx are joined by intervertebral discs and by anterior and posterior liga- 
ments. 
Movements of the Vertebral Column.—Although the amount of movement permissible 
between any two vertebree is extremely limited, yet the total range of movement capable of 
being attained by the entire vertebral column is very considerable. 
Flexion may occur both forwards and backwards at the intercentral articulations, but more 
freely in the lumbar and cervical regions than in the dorsal region, where the limited amount of — 
intervertebral disc and the imbrication of the laminze and spines restrict the movement. Back- 
ward flexion is most pronounced in the cervical region, and forward flexion in the lumbar region. 
Between the articular surfaces of the interneural articulations a variety of movements are per- 
mitted, dependent upon the directions of these surfaces, é 
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