Articulations
Synarthrosis, or immoveable
Amphiarthrosis, or mixed
Diarthrosis, or moveable
Kinds of movement
Articulations of the trunk
The vertebral column
The atlas with the axis
The atlas with the occiptal bone
The axis with the occiptal bone
Tempoko-maxillart articulation
The ribs with the vertebras
The cartilages of the ribs with the sternum
Ligaments of the sternum
The pelvis with the spine
The pelvis
Articulations of the upper extremity
Sterno-clavicular articulation
Scapulo-clavicular articulation
Proper ligaments of the scapula
Shoulder joint
Elbow joint
Radio-ulnar articulations
Whist joint
Articulations of the carpus
Capro metacapral articulations
Metacarpo-phalangeal articulations
Articulations of the phalanges
Articulations of the lower extremity
Hip joint
The knee joint
Articulations between the tibia and fibula
Ankle joint
Articulations of the tarsus
Tarso-metatarsal articulations
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The articulation of the cartilages of the true ribs with the sternum are arthro-dial joints. The ligaments connecting them are-
- Anterior Costo-Sternal; - Posterior Costo-Sternal; - Capsular; - Synovial Membranes. The Anterior Costo-Sternal Ligament (fig. 109) is a broad and thin membranous. 
The superior fasciculi ascend obliquely, the inferior pass obliquely downwards, and the middle fasciculi horizontally. The superficial fibres of this ligament are the longest; they intermingle with the fibres of the ligaments above and beneath them, with those of the opposite side, and with the tendinous fibres of origin of the Pectoralis major; forming a thick fibrous membrane, which covers the surface of the sternum, but is more distinct at the lower than at the upper part. The Posterior Costo-Sternal Ligament, less thick and distinct than the anterior, is composed of fibres which radiate from the posterior surface of the sternal end of the cartilages of the true ribs, to the posterior surface of the sternum, becoming blended with the periosteum. The Capsular Ligament surrounds the joints formed between the cartilages of the true ribs and the sternum. It is very thin, intimately blended with the anterior and posterior ligaments, and strengthened at the upper and lower part of the articulation by a few fibres, which pass from the cartilage to the side of the sternum. These ligaments protect the synovial membranes. Synovial Membranes. The cartilage of the_/?r*< rib is directly continuous with the sternum, the synovial membrane being absent. The cartilage of the second rib articulates with the sternum by means of an inter-articular ligament, attached by one extremity to the ridge which separates the two articular facets of the cartilage of the second rib, and by the other extremity to the cartilage which unites the first and second pieces of the sternum. This articulation is provided with two synovial membranes. That of the third rib has also two synovial membranes; and that of the fourth, fifth, sixth, and seventh, eich a single synovial membrane. These synovial membranes may be demonstrated by removing a thin section from the anterior surface of the sternum and cartilages, as seen in the figure. After middle life, the articular surfaces lose their polish, become roughened, and the synovial membranes appear to be wanting. In old age, the articulations do not exist, the cartilages of most of the ribs becoming firmly united to the sternum. The cartilage of the seventh rib, and occasionally also that of the sixth, is connected to the anterior surface of the ensiform appendix, by a band of ligamentous fibres, which varies in length and breadth in different subjects. It is called the costo-xiphoid ligament. Actions. The movements which are permitted in the costo-sternal articulations, are limited to elevation and depression; and these only to a slight extent. The cartilages of the sixth, seventh, and eighth ribs articulate, by their lower borders, with the corresponding margin of the adjoining cartilages, by means of a small, smooth, oblong-shaped facet. Each articulation has a perfect synovial membrane enclosed in a thin capsular ligament, strengthened externally and internally by some ligamentous fibres (intercostal ligaments), which pass from one cartilage to the other, and which are intimately united to the perichondrium. Sometimes the cartilage of the fifth rib, more rarely that of the ninth, articulate, by their lower borders, with the corresponding cartilages by small oval facets; more frequently they are connected together by a few ligamentous fibres. Occasionally, the articular surfaces above mentioned are found wanting. The outer extremity of each costal cartilage is received into a depression in the sternal end of the ribs, and held together by the periosteum. |