Clavicle
Clavicle (lat. small key), or collar bone could be easily palpated through the skin despite the body constitution. Among other functions, the collarbone protect large blood vessels and nerves passing from the thoracic inlet and spine to the upper limb.
The shortest and the most stable connection path between the spine and bones of the free upper limb (arm and hand) includes the first rib, the cartilage of the 1st rib (costosternal synchondrosis), sternum, clavicle, and scapula. In other words the clavicle is the only one upper limb's bone directly attached to the rest of the skeleton.
The classical question asked to the medical students is to define which side clavicle they keep in hands. The path to the right answer may seem surprisingly complicated for that simple-looking bone...
The list of terms:
Extremitas sternalis – Sternal (medial) endExtremitas acromialis – Acromial (lateral) end
Corpus claviculae – Body (shaft) of clavicle
Facies articularis acromialis – Acromial articular surface
...First of all, you have to find the lateral and medial end. The medial (sternal end) is thicker and rounder than the lateral one (acromial end). The next step is to define the anterior and posterior surfaces. The bone is S-shaped, and the curve of the sternal part is forward-oriented...
The list of terms:
Extremitas sternalis – Sternal (medial) endExtremitas acromialis – Acromial (lateral) end
Corpus claviculae – Body (shaft) of clavicle
Facies articularis acromialis – Acromial articular surface
Tuberositas ligamenti coracoclavicularis – Tuberosity for the coracoclavicular ligament
Facies articularis sternalis – Sternal articular surface
...Finally, the last point is defining which surface of the clavicle is superior and which is inferior. The key to the right answer is multiple irregularities on the inferior surface caused by the ligaments' attachment (lig. costoclaviculare et lig. coracoclaviculare).
The list of terms:
Extremitas sternalis – Sternal (medial) endExtremitas acromialis – Acromial (lateral) end
Corpus claviculae – Body (shaft) of clavicle
Facies articularis acromialis – Acromial articular surface
Tuberositas ligamenti coracoclavicularis – Tuberosity for the coracoclavicular ligament
Linea trapezoidea – Trapezoid line
Tuberculum conoideum – Conoid tubercle
Sulcus musculi subclavii – Subclavian groove
Facies articularis sternalis – Sternal articular surface
Impressio ligamenti costoclavicularis – Impression for the costoclavicular ligament
Last update: 03/Dec/2020