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
|
|
|
|
The articulation of the anterior arch of the atlas with the odontoid process forms a lateral ginglymoid joint, whilst that between the articulating processes of the two hones forms a double arthrodia. The ligaments of this articulation are the
- Two Anterior Atlo-Axoid; - Posterior Atlo-Axoid; - Two Capsular; - Transverse; Four Synovial Membranes. Of the Two Anterior Atlo-Axoid Ligaments (fig. IOO), the most superficial is a rounded cord, situated in the middle line, attached, above, to the tubercle on the anterior arch of the atlas; below, to the base of the odontoid process and body of the axis. The deeper ligament is a membranous layer, attached, above, to the lower border of the anterior arch of the atlas; below, to the base of the odontoid process and body of the axis. These ligaments are in relation, in front, with the Recti antici majores. The Posterior Atlo-Axoid Ligament (fig. 101) is a broad and thin membranous layer, attached, above, to the lower border of the posterior arch of the atlas; below, to the upper edge of the laminae of the axis. This ligament supplies the place of the ligamentn subflava, and is in relation, behind, with the Inferior oblique muscles. The Transverse Ligament (figs. IO2,103) is a thick and strong ligamentous band, which arches across the ring of the atlas, and serves to retain the odontoid process 
in firm connection with its anterior arch. This ligament is flattened from before backwards, broader and thicker in the middle than at either extremity, and firmly attached on each side of the atlas to a small tubercle on the inner surface of each of its lateral masses. As it crosses the odontoid process, a small fasciculus is derived from its upper and lower borders; the former, passing upwards to be inserted into tne ba-silar process of the occipital bone; the latter, downwards, to be attached to the root of the odontoid process: hence this ligament has received the name of cruciform. The transverse ligament divides the ring of the atlas into two unequal parts: of these, the posterior and larger serves for the transmission of the cord and its membranes; the anterior and smaller serving to retain the odontoid process in its position. The lower border of the space formed between the atlas and transverse ligament being smaller than the upper (on account of the transverse ligament embracing firmly the narrow neck of the odontoid process), while the central part of the odontoid process is larger than its base; this process is still retained in firm connection with the anterior arch when all the other ligaments have been divided.
The Capsular Ligaments are two thin and loose capsules, connecting the articular surfaces of the atlas and axis, the fibres being strongest on the anterior and external part of the articulation. There are four Synovial Membranes in this articulation. One lining the inner surface of each of the capsular ligaments: one between the anterior surface of the odontoid process and anterior arch of the atlas: and one between the posterior surface of the odontoid process and the transverse ligament. This synovial membrane often communicates with those between the condyles of the occipital bone and the articular surfaces of the atlas. 
Actions. This joint is capable of great mobility, and allows the rotation of the atlas, and, with it, of the cranium upon the axis, the extent of rotation being limited by means of the odontoid ligaments. ARTICULATION OF THE SPINE WITH THE CRANIUM. The ligaments connecting the spine with the craninm may be divided into two sets: Those connecting the occipital bone with the atlas; Those connecting the occipital bone with the axis. |