MUSCLES OF THE XOSE. 551 



because it is most desirable to have it as fresh as possible. This 

 will usually take two days, and he will then proceed with the 

 triangles of the neck, and it is important that he shall have 

 examined the brachial plexus, and worked up to page 599 at least, 

 in order that the dissector of the upper limb may be free to remove 

 his part at the end of the sixth day after turning the body. 



Position. The head is to be placed so that the side of the face 

 dissected is upwards, as far as the times of the students on 

 the two sides will allow, and it is to be fixed in this position with 

 hooks. 



Dissection. It is not easy to make a good dissection of the Dissection, 

 muscle*, nerves and vessels of the face on one side, and the 

 students are advised to arrange together to make out the muscles Muscles and 

 and nerves on the one side and the muscles and vessels on the other. ^T? 8 ' on 

 At the same time a good dissector can display them all on the muscles and 

 same side. As a preparatory step, the muscular fibres of the other, 

 apertures may be made slightly tense by inserting a small quantity 

 of tow or cotton wool between the eyelids and the eyeball, and 

 between the lips and the teeth, and within the cheek. 



First lay bare the orbicularis palpebrarum muscle by making a How to 

 skin-deep incision round the margin of the orbit, and raising the ^^from 

 skin of the lids towards the aperture of the eye (fig. 203, p. 553). eyelids 

 Much care must be taken in detaching the skin from the thin and 

 pale fibres of the orbicular muscle in the lids, as there is but little 

 areolar tissue between the two. 



t the integument is to be removed from the side of the face from the 

 by one incision in front of the ear from above the zygomatic arch 

 prolonging down the incision already made in the scalp to the angle 

 of the jaw, and another along the lower border of the jaw to the 

 chin : a cut should also be made along the free margin of each lip 

 from the centre to the angle of the mouth, and another round 

 the edge of the nostril. The flap of skin is to be raised from 

 behind forwards, and left adherent along the middle line. 



On the side of the nose the skin is closely united to the subjacent and from 

 parts, and must be detached with caution. Around the mouth are su 

 the orbicular muscular fibres of the lips, and from this many fleshy 

 slips extend both upwards and downwards, but they are all marked to clean 

 distinctly enough to escape injury, with the exception of the small abound 8 

 risorius muscle which goes from the corner of the mouth towards mouth - 

 the ramus of the lower jaw. While removing the fat from the 

 muscles, each fleshy slip may be tightened with hooks. 



The facial vessels and their branches will come into view as the Facial 

 muscles are cleaned (fig. 204, p. 558) ; the branches of the facial vessels > 

 nerve will be seen passing forwards from the parotid gland (fig. 205, 

 p. 562). Over the lower part of the parotid gland, near the angle 

 of the jaw, the facial branches of the great auricular nerve will be 

 found. 



In front of the ear is the parotid gland, and its duct (which is on and parotid 

 a level with the meatus auditorius, and pierces the middle of the duct 

 cheek) will be traced forwards. 



