鎖骨体とは
以下は「Wikipedia」の解説文となる。※日本語は私の方で加筆したもの。
「Shaft： The shaft is divided into the medial two-thirds and the lateral one third. The medial part is thicker than the lateral.
Medial two-thirds of the shaft
The medial two-thirds of the shaft has four surfaces and no borders.
The anterior surface is convex forward and gives origin to the pectoralis major. The posterior surface is smooth and gives origin to the sternohyoid muscle at its medial end. The superior surface is rough at its medial part and gives origin to the sternocleidomastoid muscle. The inferior surface has an oval impression at its medial end for the costoclavicular ligament. At the lateral side of inferior surface, there is a subclavian groove for insertion of the subclavius muscle. At the lateral side of the subclavian groove, the nutrient foramen lies. The medial part is quadrangular in shape where it makes a joint with the manubrium of the sternum at the sternoclavicular joint. The margins of the subclavian groove give attachment to the clavipectoral fascia.
Lateral third of the shaft
The lateral third of the shaft has two borders and two surfaces.
The anterior border is concave forward and gives origin to the deltoid muscle. The posterior border is convex backward and gives attachment to the trapezius muscle. The superior surface is subcutaneous. The inferior surface has a ridge called the trapezoid line and a tubercle; the conoid tubercle for attachment with the trapezoid and the conoid ligament, part of the coracoclavicular ligament that serves to connect the collarbone with the coracoid process of the scapula.」
