MYOLOGY 75 



Dermo-cleido Dorsalis. Location. Anterior shoulder region. 



Origin. From the upper mesial part of the clavicular bone. 



Insertion. Three fasciculi forming a fan-like arrangement at- 

 tached to the skin in the shoulder-joint and scapular region. The 

 extremities of the fasciculi may meet in the median line of the 

 dorsal region and merge with the dermo-dorsalis. 



Shape. Three fasciculi forming a fan-shaped radiation. 



Relations. Superiorly with the skin. Inf eriorly with the shoulder- 

 joint. 



Action. Contracting with the origin as the fixed point, they 

 brace the skin over the forepart of the back. With the integumental 

 attachment as the fixed point, they aid in the act of respiration. 



Cleido-trachealis. Location. Extending from the shoulder to 

 the superior laryngeal region. 



Origin. From a small area on the antero-inner part of the middle 

 of the arm of the furcula. 



Insertion. The fibers pass upward and become flattened and 

 attached to the skin and dermo-temporalis muscle. They touch 

 each other on the anterior border of the superior larynx, the trachea, 

 and the skin over these parts. 



Shape. A slender bundle of muscles. 



Relations. Superiorly the skin, and internally the larynx and 

 the trachea. 



Action.- Controls the skin region of this part of the neck. 



Dermo-spinalis. Location. In the region of the shoulder. 



Jrigin. In an attenuated fascia from the crest of the neural 

 spines of the first, the second, and the third dorsal vertebrae. 



Insertion.- To the skin in a broad pale stratum, over the scapular 

 region. 



Shape. Thin, pale, and very delicate. 



Relations. Superiorly with the skin, and inferiorly with the 

 shoulder. 



Action. Controls the skin of the region. 



Dermo-iliacus. Location. Along the back on either side of the 

 spine. 



Origin. From the inner angle of the marginal portion of the 

 antero-dorsal border of the ilium. 



Insertion. Passing forward as a delicate band it spreads out and 

 becomes lost in the skin of the shoulder region. 



Shape. Thin, delicate, and ribbon-shaped. 



