Anatomy Physiology

In a portrait of a thin female, a horizontally lying bone can most often be visible which extends from the shoulder to the breast bone. The masses know it as the ‘collar bone’ and the medics refer to it as the ‘clavicle’.

Structure:

The human clavicle is a flat bone with two heads and it has a pseudo appearance of a long bone. But, it doesn’t contain a medulla as does other long bones and therefore doesn’t contribute to the production of blood as a bone marrow. Therefore, the clavicle consists of spongy bones in the middle with a surface layer consisting of compact bones.

The two ends of the clavicle will appear differently and the lateral end would be much wider than its medial end. The wider lateral end will appear flat and the medial end will be more rounded in its appearance.

Position:

The clavicle extends from the manubrium of the breast bone or the sternum towards the acromian process of the scapulae or in other words the shoulder blade. It has a distinct appearance with two curves towards anterior and posterior directions of which the initial half extending from the sternum will curve anteriorly. The second half of the clavicle will curve posteriorly and would join with the acromian process.

Attachments:

Several muscles and ligaments will get attached to the surface of the clavicle and some of the muscles are the deltoid, trapezius, pectoral muscles, sternocleidomastoid, subclavius and sternohyoid. These muscles will form parts of the chest wall as well as the shoulder girdle and thus these attachments are rather important in maintaining the position and the functionality of the shoulder joint.

Functions:

When considering the function of a clavicle, it can be named as the joint between the upper limb and the axial skeleton. The distance that it maintains by being placed horizontally will make the upper limbs to hang independently and this will optimize the effectiveness of its range of motion. Apart from this, the clavicle will also form the roof of the cervico-axillary canal in which many vital structures pass through from neck region towards the upper arm. It further facilitates the transmission of physical stressors from the upper limb to the axial skeleton.

Clinical anatomy:

Clavicle fractures are common among the general population and a fall over an outstretched hand can give rise to such a fracture. During delivery of a newborn baby, there is a possibility of clavicle fracture due to obstruction in the labor process or else from the pressure exerted over the clavicle while pulling the baby out.

But, usually the fractures of the clavicle doesn’t last long and a broad band sling for approximately 6 weeks would be all that required in many of these fractures. It should also be understood that, the clavicle joint on either side can also be susceptible to fractures during traumatic events and therefore needs to be excluded in such events.