Page 308 - Clinical Anatomy

ECA5 7/18/06 6:50 PM Page 293

The salivary glands 293

lum linguae (Fig. 197). Here its orifice is readily visible and saliva can be
seen trickling from it.
The sublingual gland (vide infra) lies immediately lateral to the sub-
mandibular duct.
The lingual nerve reaches the tongue by passing from the lateral side of
the duct below and then medial to it—thus ‘double-crossing’ it.
The submandibular lymph nodes lie partly embedded within the gland
and partly between it and the mandible.

Clinical features

1◊◊The rather complex relations of this gland have been given at some
length because excision of the gland for calculus or tumour is not uncom-
mon. This operation is carried out through a skin crease incision below the
angle of the jaw.
The mandibular branch of VII passes behind the angle of the jaw rather
less than 1 inch from it before arching upwards over the body of the
mandible to supply the depressor of the lip. The incision must therefore be
placed rather more than 1in (2.5cm) below the angle of the jaw in order to
preserve this nerve.
2◊◊The presence of small lymph nodes actually within the substance of the
gland makes removal of the gland an imperative part of block dissection of
the neck.
3◊◊In differentiating between an enlarged submandibular gland and a
mass of submandibular lymph nodes, one remembers that the gland lies
not only below the mandible but also extends into the floor of the mouth; it
can therefore be palpated bimanually between a finger in the mouth and a
finger below the angle of the jaw. Try this on yourself. Enlarged lymph
nodes are felt only at the latter site.
4◊◊A stone in Wharton’s duct can be felt bimanually in the floor of the
mouth and can be seen if sufficiently large.

The sublingual gland

This is an almond-shaped salivary gland lying immediately below the
mucosa of the floor of the mouth and immediately in front of the deep
part of the submandibular gland. Laterally, it rests against the sublingual
groove of the mandible while medially it is separated from the base of the
tongue by the submandibular duct and its close companion, the lingual
nerve (Fig. 197).
The gland opens by a series of ducts into the floor of the mouth and also
in the submandibular duct.
The sublingual gland produces a mucous secretion, the parotid a serous
secretion and the submandibular gland a mixture of the two.
As well as these main salivary glands, small accessory glands are found
scattered over the palate, lips, cheek, tonsil and tongue. These glands are
occasional sites for development of a mixed salivary tumour.