72 ANATOMY AND PHYSIOLOGY. 



Inserted into the os occipitis, near the condyloid process. Use 

 To assist the former. 



Rectus capitis lateralis arises from the transverse process of the 

 atlas. Inserted into the os occipitis, near the mastoid process. 

 Use To move the head to one side. 



MUSCLES SITUATED ON THE POSTERIOR PART OF THE TRUNK. 



Trapezius arises from the os occipitis and the spinous processes 

 of all the vertebra? of the neck and back. Inserted into the clavi- 

 cle, part of the acromion, and the spine of the scapula. Use --To 

 move the scapula, bend the neck, and pull the head backwards. 



Latissimus dorsi arises from the spine of the ilium, spinous pro- 

 cesses of the sacrum, lumbar, and inferior dorsal vertebrae, and ad- 

 heres to the scapula and inferior false ribs. Inserted into the os 

 humeri, between the two tuberosities in the edge of the groove for 

 the tendon of the biceps muscle. Use To draw the os humeri 

 backwards, and to roll it upon its axis. 



Serratus posticus inferior arises from the spinous processes of the 

 two last dorsal and three lumbar vertebrae. Inserted into the lower 

 edge of the three or four lowermost ribs, near their cartilages. Use 

 To draw the ribs outwards, downwards, and backwards. 



Rhomboideus arises from the spinous processes of the last three 

 cervical, and first four dorsal vertebrae. Inserted into the basis of 

 the scapula, at its upper and lower part. Use To move the 

 scapula upwards and backwards. 



Splenius arises from the spines of the four last cervical and four 

 superior dorsal vertebrae. Inserted into the two first cervical ver- 

 tebra, and the side of the os occipitis. Use To move the head 

 backwards, and also to one side. 



Serratus superior posticus arises from the spinous processes of 

 the three last cervical, and two superior dorsal vertebrae. Inserted 

 into the second, third, and fourth ribs, by three neat fleshy tongues. 

 Use To expand the thorax by elevating the ribs. 



Spinalis dorsi arises from two spinous processes of the loins, and 

 three lower of the back. Inserted into all the spinous processes of 

 the back, except the first. Use To extend the vertebrae. 



Levatores costarum arises from the transverse processes of the 

 last cervical and .the dorsal vertebrae. Inserted into the angles of 

 the ribs. Use To lift the ribs upwards. 



Sacro-lumbalis arises from the sacrum, spine of the ilium, and the 

 spinous and transverse processes of the lumbar vertebrae. Inserted 



