LIGAMENTS AND MU8CLES OF THE HOUSE. 87 



Insertion. — To the posterior extremity of the great cornu of 

 hyoid bone. 



Action.— To retract the hyoid bone and attached structures. 



{Note. — This muscle covers the guttural pouch, and is perfor- 

 ated in opening the pouch). 

 6. Hyoideus Transversus. 



An unpaired muscle stretching across the mediam line be- 

 tween the small cornua of the hyoid bone, to which it is 

 attached. 



Action. — To raise the root of the tongue. 



PECTORAL REGION. 



1. Anterior superficial iw,ctoTal. 3. Anterior deep fector at. 



2. Posterior superficial pectoral. 4. Posterior deep pectoral. 



1. Anterior Superficial Pectoral (pectoralis anticus). 



Origin. — From the cariniform cartilage, and first two or three 



inches of inferior border of the sternum. 

 Insertion. — To the deltoid ridge of the humerus. 

 Action. — Adduction. 



2. Posterior Superficial Pectoral (pectoralis transversus). 



Origin. — From the inferior border of the sternum, from within 



an inch of its anterior extremity back to the sixth costal 



cartilage. 

 Insertion. — { Principally) to the fascia on the inner surface of 



the fore-arm, and by a small band to the deltoid ridge of 



the humerus. 

 Action. — It adducts the fore-limb, and also tenses the fascia of 



the fore-arm. 



3. Anterior Deep Pectoral (pectoralis parvus). 



Origin. — From the cartilages of the first four ribs, and the ad- 

 jacent lateral surface of the sternum. 

 Insertion. — To the fascia of the antea-spinatus muscle. 

 Action. —To draw the scapula backwards and downwards. 



