THE NOSE AND MOUTH. 



125 



will be often referred to in the course of our work ; /, m, o, and p, arc muscles em- 

 ployed for this purpose. 



THE MUSCLES, NERVES, AUD BLOOD-VESSELS OF THE HEAD AND UPPER PART OF THE NECK. 



a The upper part of the hgament of the neck. 



6 The levator humeri (elevator of the shoulder), arising from the tubercle of the occiput, ih° 

 mastoid (tiipple-shapcd) process of the temporal bone, and the transverse processes 

 (cross projections) of the four first bones of the neck, and the ligament of the neck, ana 

 going to the muscles of the shoulders, and the upper bone of the arm : to draw for- 

 ward the shoulder and arm ; or turn the head and neck ; and, vv'hen the two levators 

 act, to depress the head. 



C The tendon common to the complexus major (larger complicated), and splenius (splint-like) : 

 to the mastoid process of the temporal bone, to hold up the head, or, the muscles on 

 one side alone acting, to turn it. 



d The sterno-maxillaris (belonging to the breast-bone) and upper jaw, from the cartilage in 

 front of the chest to the angle of the lower jaw : to bend the head, or, if one only 

 acts, to bend it on one side. 



e The stylo-maxillaris. from the styloid (pencil-shaped) or coracoid (beak-shaped) process of 

 the occiput, to the angle of the jaw : to pull the jaw backward and open it. 



y The suhscapulo hyoideus, from under the shoulder-blade, to the body of the os hyoides (the 

 bone at the root of the tongue formed like a Greek u, v) : to draw back that bone. 



g The masseter (chewing) ; a most powerful muscle, constituting the cheek of the horse : — 

 from the upper jaw bone into the rough surface round the angle of the lower : in con- 

 junctiiin with the temporal muscle to close the mouth and chew the food. 



h The orbicularis (circular) surrounding the eye and closing the lids. 



i The zi/i;omaticus, from the zygomatic arch and masseter to the corner of the mouth, to 

 draw back the angle of I he mouth. 



k The buccinator (trumpeter), from the inside of the mouth and cheeks, to the angle of the 

 mouih, to draw u back. 



I The vasalis lahii superioris (belonging to the nose and upper lip), from a depression at the 

 junction of the superior maxillary and malar bones, to the angle of the nostril : to raise 

 the lip, and dilate the nostrils. 



m Dilator naris lateralis (side dilator of the nostril), reversed to show the vessels and nerves 

 which it covers, going from the covering of the nasal and frontal bones, to the angle 

 of the mouth, and side of the nostril: to retract the upper lip and dilate the nostrils. 



w Dilator ma^mi': (areat dilator), assisting in the same office. 



Depressor lahii biferioris (puller down of the under lip), to the sides of the under lip : to pull 

 it down. 



p Orbicularis oris (circular muscle of the mouth), surrounding the mouth : to close the lips 

 and dilate the nostrils. 



9 The upper poriion of the parotid gland (gland near the ear) reversed, to show the blood-ves- 

 sels and iu=!rves beneath it. 



T The parotid dact piercing the cheek, to discharge the saliva mto die mouth. 

 11* 



