Anatomical area which attaches the thoracic member to the trunk.
Made of two bones: into dorsal, the scapula into ventral, the clavicle
The belt scapular is an area hinge, a crossroads, an area of passage for the vessels, the nerves and the lymphatic ones of the thoracic member.
The scapula (Scapula)
Flat bone, thin, located in the area dorso-crâniale of the thorax, mobile, it covers 6 to 7 coasts (of 2nd with 7th or 8th)
Triangular bone which presents to describe:
- 2 surfaces
- 3 borders
- 3 angles
1) Surfaces :
- a dorsal
a) - The Ventral or Costal Surface
It is slightly dug (excavated) (concave into ventral); it is divided into two parts:
* a central part: who presents 3 or 4 peaks which move in crânial and side, they give insertions to the muscle sub-scapular, (subscapular): pit sub-scapular.
* a peripheral part: circumference, thick resistant very marked into side: the pillar of the scapula.
b) - The Dorsal Face
present an element which divides it into two irregular parts: the spine scapular it is at the level from the 1/4 crânial dorsal face.
The spine forms a triangular transverse blade which partitions the dorsal face of the scapula. It presents a bulge, the tuber of the trapezoid it is prolonged at its side end by a bulky tuber: the acromion which supports an articular facet on its edge médial being articulated with the clavicle.
The spine determines with the dorsal face of glene of the scapula the notch spino-glénoïdale.
The spine separates the dorsal face from the scapula in two pits of muscular insertions.
* Supra-thorny area: Supra-thorny pit
Insertion du muscle supra-épineux (sus-épineux )
* Infra-thorny area: Infra-thorny pit
Itself partitioned by a vertical peak, (into side) which separates the area into two:
- in médial of the peak fits the muscle infra-thorn-bush (infraspinator)
- into side of the peak fits the round muscles of the shoulder (small round in crânial) (large round into caudal).
2) EDGES: There are three edges which take the name of the area that they look at.
a) The Médial Edge, looks at the line of centers: EDGE SPINAL
It presents an obtuse angle compared to the spine.
b) The Side Edge, it looks towards the hollow axillaire: EDGE AXILLAIRE (PILLAR OF THE SCAPULA).
c) The Crânial Edge, looks towards the neck: CERVICAL EDGE
This edge presents a constant notch in which pass from the vessels and the nerves (artery and nerve supra-scapulars). It is located close to the process coracoïde in médial of him, incisure scapular (notch coracoïdienne).
3) ANGLES with the junction of the edges.
a) The Caudal Angle: point scapula corresponds to 7th or 8th coast.
b) The Crânial Angle: corresponds to 1st or 2nd coast.
c) The Side Angle: is bulky and important.
This angle presents three formations:
- une partie articulaire
- a muscular zone of insertion
- the collar of the scapula.
* Articular surface: Glénoïdale cavity of the scapula. Surface ovalaire, pyriforme, very slightly dug; it is articulated with the head humérale, and takes part in the principal articulation of the shoulder.
It looks in crânial, side and ventral.
It presents in its center a tuber: the tuber glénoïdien; at its two ends, there are two other tubers apart from articular surface:
- in crânial, the tuber supra glénoïdal (muscle biceps),
- into caudal, the tuber will infra glénoïdal (triceps muscle ).
* The process: Coracoïde process:
In the shape of hook (bent finger), whose end is directed into ventral and laterally. It gives insertion to three muscles: The small pectoral one, the coraco brachial, the biceps brachial (short portion).
There is a thick ligament tended of the acromion to the process coracoïde: the ligament coraco-acromial, it forms a vault which overhangs the articulation of the shoulder.