S o PRACTICAL ANATOMY. 



The Temporal Muscle (Fig. 25). Cut the aponeurosis of this muscle around 

 the whole circumference of the temporal fossa. The aponeurosis will be attached 

 to the zygoma in two layers. Find between these two layers a small branch of 

 the temporo-malar nerve. The nerve will do you no good ; but finding the 

 same will be evidence of careful work. Turn the muscle itself down, after hav- 

 ing removed the fascia, and see the deep temporal arteries. These supply the 

 muscle with blood. They lie on the bone. They are branches of the internal 

 maxillary. Find the deep temporal vein (Fig. 18) piercing the fascia above the 

 zygoma, to join the superficial temporal. 



The sterno-cleido-mastoid muscle (Fig. 25) has two origins : (i) A sternal ; 





( 





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FIG. 25. MUSCLES OF THE FACE AND NECK. 



I. Frontal muscle. 2. Occipital muscle. 3, 3. Epicranial aponeurosis. 4. Temporal muscle. 5. Retra- 

 hens aurem. 6. Orbicularis palpebrarum. 7. Levator labii superioris et akeque nasi. 8. Dilator 

 naris. 9. Compressor naris. 9'. Pyramidalis nasi. 10. Zygomatic minor. II. Zygomatic major. 

 12. Masseter. 13. Levator anguli oris. 14. Levator labii superioris. 15. Orbicularis oris. 16. 

 Buccinator. 16'. Depressor anguli oris. 17. Depressor labii inferioris. 18. Levator labii inferi- 

 oris. 19. Sterno-mastoid. 20. Trapezius. 21. Digastric and stylo-hyoid. 22. Anterior belly of 

 digastric. 23. Pulley for tendon of digastric. 24, 24. Omo-hyoid. 25. Sterno-hyoid. 26. Thyro- 

 hyoid. 27. Mylo-hyoid. 28. Splenius capitis. 29. Splenius colli. 30. Levator anguli scapula:. 

 31. Scalenus posticus. 32. Scalenus anticus. 



(2) a clavicular. Its size, location, and extensive nerve-supply make it the most 

 important muscle in the neck. These origins vary in size. In some cases you 

 will find the clavicular part very small, in other cases very large. The sternal 

 origin corresponds to the mastoid insertion ; the clavicular origin corresponds to 

 the occipital insertion. If you will follow the cleft between the two heads, it 

 will lead you to the junction between the occipital and mastoid. (Fig. 23.) 



Sterna- inastoid sheath (Fig. 24) is formed by a delamination of the first layer 

 of deep cervical fascia. Cut through this sheath from end to end, just as you 

 would separate two muscles. In fact, as pointed out in the preceding paragraph, 

 there are two muscles here, coalesced to form one. 



