Submandibular Gland

Borders

The mylohyoid muscle runs through the lobules of the gland and sections it off into superficial and deep parts. The superficial portion of the submandibular gland can be seen in the submandibular triangle of the neck and is covered by the investing layer of deep cervical fascia. The deep portion of the submandibular gland is that which limits the inferior aspect of the oral cavity. It lies between the hyoglossus muscle and the mandible. It ends at the posterior border of the sublingual gland.

Histology

This glandular mass is responsible for the production of 70% of the over salivary output. It secretes both serous and mucinous saliva, although the majority of it is serous, with a 3:2 ratio in it’s favor.

It’s duct, which connects the gland with the oral cavity proper is known as Wharton’s duct and opens at the lingual papilla, which can be found on either side of the lingual frenulum. It runs along the gland and is approximately four centimeters in length and between two and four millimeters wide.

Blood Supply

The facial and lingual arteries contribute to the blood supply of the submandibular gland and in turn their venous drainage is provided by the corresponding veins.

Innervation

The secretory mechanism of the submandibular gland is regulated directly by the parasympathetic nervous system by which it is stimulated, and indirectly by the sympathetic nervous system by which it is inhibited. These exact fibers include presynaptic fibers from the facial nerve (CN VII) via the chorda tympani to the submandibular ganglion and postsynaptic fibers from cells in the submandibular ganglion that together make up the parasympathetic secretomotor fibers. The vasoconstrictive sympathetic fibers stir from the superior cervical ganglion.