Digestive Glands and Associated Organs
General structure of the major salivary glands.
are structurally very similar to one another, although they produce various
secretions. Each unit of the salivary glands can be divided into a
, or a
of both. These secretory cells are arranged into acini resembling grapes on a stem (interca-
lated duct). Several serous cells form a cap, called a
, on the outer aspect of mucous cells; this arrangement can be
found in the mixed glands. A capsule (dense connective tissue layer) surrounds an entire gland. Connective tissue septa penetrate the
gland and subdivide it into
(located within the lobules),
(outside or between the lobules),
, and a
empties the secretory products (saliva) into the oral cavity.
130 skin, palm.
are paired glands and are the largest of the major
salivary glands. They are located anterior to and below the lower
half of the ear, and superior, posterior, and deep to the ramus of
the mandible. The
of each parotid gland passes through
the cheek and opens into the oral cavity near the second upper
molar tooth (see Fig. 16-1). The parotid glands are composed of
. They are classi±
based on their duct shape and secretory units (see Fig.
3-27A). This photomicrograph shows
striated ducts (intralobular
located in the lobules. The striated ducts are lined by taller
cuboidal (or columnar) cells with centrally located nuclei (see Fig.
16-7A). Connective tissue septa divide the gland into small lobules,
and there are some adipose cells distributed in among the serous
acini. Each acinus is formed by several serous cells with basally
positioned dark nuclei (Fig. 16-4A).
Salivary Gland Duct System
(a few branches)
Lumen of the
(Serous, mucous, or mixed cells)
(Simple low cuboidal epithelium)
Small intralobular duct
(Stratified columnar epithelium)