xiv MUSCLES AND EXERCISE 195 



136. Large Muscles. 

 I. MUSCLES OF THE HEAD. 



1. Occipito-fron tails, moves the scalp and eyebrows, and 



throws the forehead into transverse wrinkles. 



2. Orbicularis palpebrarum, moves the eyelids and closes 



the eye. 



3. Corrugator supercilii, used in frowning. 



4. Levator palpebrae, opens the eye. 



5. The recti, the four straight muscles of the eyeball. 



6. Orbicularis oris, closes the mouth. 



7. Buccinator, compresses the cheeks, and is used in 



mastication. 



8. Risorius, draws up the angles of the mouth as in smiling. 



9. Temporal, or muscle of the temple, raises the lower 



jaw. 

 10. Masseter, or chewing muscle, raises the lower jaw. 



II. MUSCLES OF THE NECK. 



n. Platysma myoides, draws down the lower lip and the 

 angles of the mouth. 



12. Sterno-cleido-mastoid, depresses the head and neck upon 



the chest. 



13. Scaleni muscles, elevate the ribs in breathing. 



III. MUSCLES OF THE TRUNK. 



14. Trape2ius, draws the head backward, and elevates the 



shoulder. 



15. Latissimus dorsi, draws the arm backward as in chop- 



ping or in striking down. 



1 6. Rhomboideus, draws the shoulder back. 



17. Erector spinae, holds the spine erect. 



1 8. Intercostals, move the ribs in breathing. 



19. Diaphragm, used in breathing. 



20. External oblique ) These muscles form the walls of 



21. Internal oblique the abdomen, pull the trunk for- 



22. Transversalis ward, and compress the abdomi- 



23. Rectus abclominis J nal organs. 



