Let us Summarise the Clavicle in the shortest possible form we can.
The Clavicle is a long bone. It lies horizontal in the body. The clavicle acts as a strut that allows the the upper limb to fling away from the trunk.
As a long bone, the clavicle has a shaft and two ends - The medial end or the sternal end and the Lateral or Acromial end.
The clavicle has the shape of a capital "S".
The shaft of the clavicle can be divided into three thirds - A medial two-third and a lateral one third. The medial two-third is convex anteriorly while the lateral one-third is concave anteriolry. The medial two-third of the clavicle has a round shape with four surfaces - the Anterior, Posterior, Superior, and The Inferior surface.
At the Anterior surface of the medial two-third of the clavicle, originates the clavicular head of the Pectoralis major.
The Posterior surface gives origin to the sternohyoid muscle.
The superior surface gives origin to the clavicular head of the sternocleidomastoid.
The inferior surface of the medial two-third of the clavicle is rough. It has a rough oval impression both at the medial and lateral ends. The impression at the medial end is called the Rhomboid fossa is is the point of attachment of the Costoclavicular ligament. The rough impression at the lateral end of the medial two-third of the clavicle is the point of attachment of the Coracoclavicular ligament. There is also a longitudinal groove at the middle of this inferior surface which is the point of insertion of the Subclavius muscle. The clavipectoral fascia attaches at the margins of this groove.
Now let us go to the Lateral one-third of The Clavicle: The Lateral one-third of the clavicle has two surfaces - the superior surface and the Inferior surface; and two borders - the anterior border and the Posterior border.
The Anterior border gives origin to the deltoid muscle. The Posterior border is the point of insertion of the Trapezius.
The Superior surface of the clavicle is smooth while the inferior surface is rough and has a depression called the conoid tubercle and a ridge called the trapezoid ridge. They give attachment to the conoid and trapezoid parts of the coracoclavicular ligaments.
The clavicle is shorter, smoother, thinner, lighter and less curved in females than in males. The right clavicle is shorter and stronger than the left. The clavicle may be congenitally absent.
The two ends of the Clavicle: The clavicle has two ends - the medial or sternal end and the lateral of the acromial end.
The medial end is thickened and quagrangular. It articulates with the manubrium of the sternum and the first costal cartilage.
The lateral or acromial end is flattened. It articulates at the acromion of the scapula.
Peculiarities of the Clavicle: These are facts that are peculiar to the clavicle.
1. The Clavicle is the only long bone that lies horizontal in the long.
2. It is subcutaneous throughout its length.
3. The clavicle is the first bone to start ossification and the last to end ossification.
4. The clavicle is the only long bone that ossifies in the membrane.
5. The clavicle is the only long bone that has two primary centers of ossification
6. The clavicle does not usually have medullary cavity.
Kindly drop your comments and contributions as regards the topic - THE CLAVICLE
The Clavicle is a long bone. It lies horizontal in the body. The clavicle acts as a strut that allows the the upper limb to fling away from the trunk.
As a long bone, the clavicle has a shaft and two ends - The medial end or the sternal end and the Lateral or Acromial end.
The clavicle has the shape of a capital "S".
The shaft of the clavicle can be divided into three thirds - A medial two-third and a lateral one third. The medial two-third is convex anteriorly while the lateral one-third is concave anteriolry. The medial two-third of the clavicle has a round shape with four surfaces - the Anterior, Posterior, Superior, and The Inferior surface.
At the Anterior surface of the medial two-third of the clavicle, originates the clavicular head of the Pectoralis major.
The Posterior surface gives origin to the sternohyoid muscle.
The superior surface gives origin to the clavicular head of the sternocleidomastoid.
The inferior surface of the medial two-third of the clavicle is rough. It has a rough oval impression both at the medial and lateral ends. The impression at the medial end is called the Rhomboid fossa is is the point of attachment of the Costoclavicular ligament. The rough impression at the lateral end of the medial two-third of the clavicle is the point of attachment of the Coracoclavicular ligament. There is also a longitudinal groove at the middle of this inferior surface which is the point of insertion of the Subclavius muscle. The clavipectoral fascia attaches at the margins of this groove.
Now let us go to the Lateral one-third of The Clavicle: The Lateral one-third of the clavicle has two surfaces - the superior surface and the Inferior surface; and two borders - the anterior border and the Posterior border.
The Anterior border gives origin to the deltoid muscle. The Posterior border is the point of insertion of the Trapezius.
The Superior surface of the clavicle is smooth while the inferior surface is rough and has a depression called the conoid tubercle and a ridge called the trapezoid ridge. They give attachment to the conoid and trapezoid parts of the coracoclavicular ligaments.
The clavicle is shorter, smoother, thinner, lighter and less curved in females than in males. The right clavicle is shorter and stronger than the left. The clavicle may be congenitally absent.
The two ends of the Clavicle: The clavicle has two ends - the medial or sternal end and the lateral of the acromial end.
The medial end is thickened and quagrangular. It articulates with the manubrium of the sternum and the first costal cartilage.
The lateral or acromial end is flattened. It articulates at the acromion of the scapula.
Peculiarities of the Clavicle: These are facts that are peculiar to the clavicle.
1. The Clavicle is the only long bone that lies horizontal in the long.
2. It is subcutaneous throughout its length.
3. The clavicle is the first bone to start ossification and the last to end ossification.
4. The clavicle is the only long bone that ossifies in the membrane.
5. The clavicle is the only long bone that has two primary centers of ossification
6. The clavicle does not usually have medullary cavity.
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| The Left Clavicle. Image credit: wikipedia |
Kindly drop your comments and contributions as regards the topic - THE CLAVICLE
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