Clavicle

:''Collarbone and '''collar bone''' redirect here. The eye abnormality is correctly spelt Coloboma .''
In Human Anatomy , the clavicle or '''collar bone''' is a Bone that makes up part of the Shoulder girdle (pectoral girdle).

OVERVIEW

It is a doubly-curved long bone (the only horizontal long bone in the body) that connects the arm ( Upper Limb ) to the body ( Trunk ), located directly above the first rib. Medially, it articulates with the manubrium of the Sternum (breast-bone) at the Sternoclavicular Joint . At its lateral end it articulates with the Acromion of the Scapula (shoulder blade) at the Acromioclavicular Joint . It is shorter, thinner, less curved, and smoother in women than in men. It has a rounded medial end and a flattened lateral end.

FUNCTIONS

The clavicle serves several functions:

It serves as a rigid support from which the scapula and free limb are suspended. This arrangement keeps the upper limb away from the thorax so that the arm has maximum range of movement.

Covers the cervicoaxillary canal (passageway between the neck and arm), through which several important structures pass.

Transmits impacts from the upper limb to the Axial Skeleton .

Even though it is classified as a Long Bone , the clavicle has no medullary (bone marrow) cavity like other long bones. It is made up of spongy (cancellous) bone with a shell of Compact Bone .

ATTACHMENTS

Muscles and ligaments that attach to the clavicle include:

Superior surface:

Deltoid Muscle at the deltoid tubercle, anteriorly on the lateral third.

Trapezius Muscle posteriorly on the lateral third.

Subclavius Muscle at the subclavian groove

Conoid ligament (the medial part of the Coracoclavicular Ligament ) at the conoid tubercle

Trapezoid ligament (the lateral part of the Coracoclavicular Ligament ) at the trapezoid line

Pectoralis Major Muscle on the medial third (rounded border)

Deltoid Muscle on the lateral third of border in the deltoid tubercle

Sternocleidomastoid Muscle superiorly, on the medial third (clavicular head of Sternocleidomastoid)

Sternohyoid inferiorly, on the medial third

Trapezius on the lateral third

DEVELOPMENT

The clavicle is the first bone to begin the process of harderning ( Ossification ) during development of the embryo, during the 5th and 6th weeks of gestation. However, it is the last of the long bones to finish ossification, at about 21 years of age. It forms by Intramembranous Ossification .

COMMON CLAVICLE INJURIES

Acromioclavicular Dislocation

Sternoclavicular Dislocations

Clavicle Fracture s

Osteolysis

Degeneration Of The Clavicle

NOTE ABOUT ANATOMICAL POSITION

''Note: this article uses some professional terms to explain certain anatomical details. These words apply only when the body is in '''anatomical position''', i.e., standing with palms of the hands facing forward. These terms are'':

''superior'' - ''above''

''inferior'' - ''below''

''abduction'' - ''the movement of the limb away from the body''

''medial'' - ''toward the midline''

''lateral'' - ''away from the midline''

Anatomical Position

Information About

Clavicle