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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This form of articulation includes the greater number of the joints in the body, mobility being their distinguishing character. They are formed by the approximation of two contiguous bony surfaces, covered with cartilage, connected by ligaments, and having a synovial sac interposed. The varieties of joints in this class, have been determined by the kind of motion permitted in each; they are four in number:
- Arthrodia; - Enarthrosis; - Ginglymus; - Diarthrosis; - Rotatorius. Arthrodia is that form of joint which admits of a gliding movement; it is formed by the approximation of plane surfaces, or one slightly concave, the other slightly convex; the amount of motion between them being limited by the ligaments, or osseous processes, surrounding the articulation; as in the articular processes of the vertebrae, temporo-maxillary, sterno and acromio-clavicular, inferior radio-ulnar, carpal, carpo-metacarpal, superior tibio-fibular, tarsal, and tarso-meta-tarsal articulations. Enarthrosis is that form of joint which is capable of motion in all directions. It is formed by the reception of a globular head into a deep cup-like cavity (hence the name ' ball and socket'), the parts being kept in apposition by a capsular ligament strengthened by accessory ligamentous bands, and the contiguous cartilaginous surfaces having a synovial sac interposed. Examples of this form of articulation are found in the hip and shoulder-joints. Ginglymus, Hinge-joint . In this form of joint, the articular surfaces are moulded to each other in such a manner, as to permit motion only in one direction, forwards and backwards, the extent of motion at the same time being considerable. The articular surfaces are connected together by strong lateral ligaments, which form their chief bond of union. The most perfect forms of ginglymi are the elbow and ankle; the knee is less perfect, as it allows a slight degree of rotation in certain positions of the limb: there are also the metatarso-phalangeal and phalangeal joints in the lower extremity, metacarpo-phalangeal and phalangeal joints in the upper extremity. Diarthrosis rotatorius (Lateral Ginglymus). Where the mobility is limited to rotation, the joint is formed by a pivot-like process turning within a ring, or the ring on the pivot, the ring being formed partly of bone, partly of ligament. In the articulation of the odontoid process of the axis with the atlas, the ring is formed in front by the anterior arch of the atlas; behind, by the transverse ligament; here the ring rotates around the odontoid process. In the superior radio-ulnar articulation, the ring is formed partly by the lesser sigmoid cavity of the ulna; in the rest of its extent, by the orbicular ligament; here, the neck of the radius rotates within the ring. Subjoined, in a tabular form, are the names, distinctive characters, and examples of the different kinds of articulations. |