ARTICULATION OF THE LOWER JAW. 49 



partly ligament and partly cartilage : found in the ear, at the sym- 

 physis pubis, and between the vertebree. 



Ligmnents consist o^ fibrous tissue, Ox^ which there are two kinds, 

 white and yellow / an example of the white is found in tendons, 

 fasciae, and most of the ligaments ; the yellow is found in the liga- 

 mentum nuchse, and in many vessels and ducts. It is elastic. 



Ligaments are called capsular when they are bag-like, as at the 

 shoulder and hip ; funicular, when cord-like, and membranous when 

 like a riband. 



Synovial membranes are thin, transparent, closed serous sacs, 

 lining capsular ligaments, and secreting an albuminous fluid called 

 synovia, which resembles in appearance the white of an egg. It 

 lubricates the joints, and prevents attrition. Masses of fat outside 

 of the synovial membranes are usually called glands of Havers. 

 They do not secrete, however, but serve a mechanical purpose in 

 the mechanism, filling up spaces which would otherwise be formed 

 in many articulations during the performance of certain movements. 

 The synovial fringes are nothing but folds of this membrane in- 

 cluding small portions of fat. 



The principal kind of articulations are termed : 

 Synarthrosis, implying immobility, and including 

 Sutura. — Bones of the skull. 

 Harmonia. — Superior maxillary bones. 

 Schindylesis. — Vomer with processus azygos. 

 Gomphosis. — Teeth with alveoli. 

 Amphiarthrosis implies partial motion, and is exemplified in the 

 symphyses and bodies of vertebroe. 



DiARTHRosis is a movable articulation, and includes — 

 Arthrodia. — Tarsal and carpal bones. 

 Ginglymus. — Elbow — wrist — hinge-like. 

 Enarthrodia. — Hip, shoulder, ball and socket. 



ARTICULATION OF LOWER JAW. 



Capsular Ligament. — Extends from the border of the glenoid ca- 

 vity of the temporal bone, and 



surrounds the neck of the con- Fig.SO. 



dyloid process of the lower jaw. 



External Lateral Ligament.^ 

 — Is broad and triangular, cover- 

 ing the outside of the joint, ex- 

 tending from the tubercle at the 

 root of the zygoma to the outside 

 of the neck of the condyle — 

 (Fig. 30). 



Internal Lateral Ligament. — 

 Properly speaking, not a liga- 

 ment but a fibrous band or sheath 



