TERY.
The veins are principally branches of the external jugular, viz. 1. the facial vein with its branches, which correspond generally to the trunk and branches of the facial artery, except that the facial vein is rather more superficial and further from the median line than the artery; 2. the transverse facial vein and some other small branches of the temporal; 3. veins corresponding to the branches of the internal maxillary artery already mentioned; and, lastly, some veins about the nose and brow, which are connected with the ophthalmic vein within the orbit. Both arteries and veins are imbedded in the adipose tissue, and are often remarkably tortuous, more especially the ar teries, in old persons. Their trunks and branches open in a direction towards the me dian line, particularly at the upper part of the face.
The lymphatics are much more numerous than those of the cranium, and follow prin cipally the course of the bloodvessels, and terminate in the submaxillary and parotid lym phatic ganglions; in their course they traverse some ganglions, which are situated on the hue cinator.
The superficial lymphatics arise from all parts of the face, and, accompanying the su perficial vessels, end in the submaxillary gan glions; some of them traverse the smaller buccal ganglions.
The deep lymphatics are situated in the zy gomatic and pterygo-maxillary fossw ; they also accompany the bloodvessels, and ter minate in the deep parotid and submaxillary ganglions.
The lymphatic ganglions of the face are prin cipally situated along the base of the jaw, and are termed the submaxillary ganglions. Others are placed on the jaw and buccinator, in front of the masseter (the buccal ganglions), and follow the facial vessels. Some lymphatic ganglions are situated underneath the zygoma (the zygomatic ganglions); and others, more numerous, are placed upon, within, or under neath the parotid gland, and are termed the parotid ganglions. The deep lymphatics of the orbits, nose, and mouth, will be described with those cavities.
The nerves cf the are derived from the three divisions of the fifth and from the portio dura of the seventh cerebral nerves. The
branches from the fifth emerge on the face, I. from the orbit ; these come from the oph thalmic or first division of the fifth, and are the frontal, the supra-trochlear, the infra trochlear, and the lachrymal : 2. from the infra-orbitar foramen escape the infra-orbitar nerve, from the second division of the fifth or superior maxillary, and from the same source, emerging from underneath the ramus of the jaw, the buccal nerves : 3. from the mental foramen emerge branches of the inferior den tal nerve, derived from the third division of the fifth or the inferior maxillary ; and from the same source, piercing the masseter, the masseteric nerves. The portio dura, after turn ing over the posterior border of the lower jaw, forms a plexus (the fines anserinus) within the parotid gland, and divides into a great num ber of branches, which are distributed on the face, and which have received various names corresponding to the regions where they run. The branches of the fifth nerve which are dis tributed to the face principally supply the in teguments, and those of the portio dura the muscles. Some filaments, however, of the fifth, such as the buccal branch, derived from the ganglionous portion, supply muscles ; and, on the other hand, some cutaneous twigs are sent from the portio dura of the seventh to the commissure of the lips. Both nerves freely anastomose with each other on the face. For a more particular account of these nerves and of their functions, see Firm] PAIR or NERVES, SEVENTH PAIR OF CEREBRAL NERVES, and PHYSIOGNOMY.
Abnormal conditions of the soft parts the face.—The muscles of the thee offer nothing very remarkable in their abnormal conditions ; like others, they become much developed by constant exercise, and on the other hand, when paralytic, they waste and lose both their colour and consistence; their fibres have been ob served occasionally to have degenerated into a fatty substance, and the trichina spirals has also been found among them as among those of other voluntary, muscles.