SALIVARY GLANDS
Figure 13­23
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There are three major pairs of salivary glands associated with the oral cavity and several minor salivary glands, such
as von Ebner's glands, in the lamina propria of the tongue. The three major salivary glands, parotid, submandibular,
LLC.
and sublingual, consist of secretory units (acini) and a system of ducts to convey the secretions to the oral cavity.
The secretory acini constitute the parenchyma and the ducts are found, in part, in the stromal tissue. The activity of
Not
the glands is reflected in the fact that they produce, on the average, between 750 and 1000 mL of saliva per day.
to
be
redistributed
Saliva contains enzymes, glycoproteins, proteoglycans, ions, and water. It functions to initiate the digestion of food,
moisten the mucous surfaces of the oral cavity, and, by means of immunoglobulin A and lysozyme, provide protec-
tion from bacteria.
or
The major salivary glands differ in their structural composition and in the types of salivary fluid that they produce.
modified
The parotid gland shown in this micrograph secretes a watery solution high in enzyme and antibody concentrations.
The parotid glands are located subcutaneously on both sides of the face. They consist almost entirely of serous acini,
in
ducts, connective tissue with its nerves (a branch of the facial nerve passes through the parotid gland), and blood
any
vessels. The thin connective tissue capsule extends septa into the gland to divide it into lobules. Adipose tissue is
way
interspersed among the acini. The abundance of connective tissue septa makes this organ difficult to dissect in the
without
anatomy laboratory.
permission.
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