Page 525 - Atlas of Histology with Functional Correlations

SECTION 2 Major Salivary Glands

There are three major salivary glands for the oral cavity: parotid,

submandibular, and sublingual. Salivary glands are located outside the oral
cavity and convey their secretions into the mouth via excretory ducts. The
paired parotid glands are the largest of the salivary glands, located anterior and
inferior to the external ear. The smaller and also paired submandibular
(submaxillary) glands are located inferior to the mandible in the floor of the

mouth. The smallest salivary glands are the sublingual glands; these are
aggregates of smaller glands located inferior to the tongue.

Salivary glands are surrounded by dense connective tissue capsules from
which septa subdivide the secretory areas into lobes and lobules. Each salivary

gland is composed of cellular secretory units called acini (singular, acinus) and
excretory ducts with variable histologic features, depending on their location in
the gland. The secretory units are small, saclike dilations located at the beginning
of the first segment of the excretory duct system called the intercalated ducts.

CELLS OF SALIVARY GLAND ACINI

Secretory cells of salivary glands are of two types: serous or mucous. The acini
exhibit either serous cells that produce protein-rich watery secretions or mucous
cells that secrete mucus or a mixture of acini cells that produce both types of
secretions (Fig. 13.17).

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