The human clavicle is what we commonly call the collarbone. It is a slender, tubular and S-shaped bone. It has a lateral and a medial end. The lateral tip is the acromial end, which articulates with the acromium of scapula. The medial extremity, on the other hand, is called the sternal end, which articulates with the manubrium sterni of sternum.
The acromial end of human clavicle is wider but slightly thinner than the sternal end, which has a sternal articular facet. Looking at it from above, the sternal half of the collarbone makes a forward curve. The inferior surface of the sternal end bears the costal tuberosity, which serves as the site of attachment for the costoclavicular ligament. The inferolateral surface of the lateral end features the acromial articular facet.
The acromial end also bears the conoid tubercle and the trapezoid line, which give attachment to the conoid and trapezoid parts of the coracoclavicular ligament.
Below, the superior and inferior view of right human collarbone.