Submandibular Gland

SUBMANDIBULAR GLAND

• Mixed type of salivary gland (contains both mucous & serous acini) but is predominantly serous in nature.
• This walnut sized gland lies below the mandible in the anterior part of digastric triangle.
• It is J-shaped and consists of a large superficial and a small deep parts, separated by mylohyoid muscle and continuous with each other around the posterior border of mylohyoid muscle.

Superficial part:

• It is situated in the anterior part of digastric triangle. The gland is partially closed in a capsule formed by two layers of deep cervical fascia.

It has three surfaces:

• Inferior surface is covered by skin, platysma, cervical branch of facial nerve, dep fascia, facial vein and submandibular lymph nodes.
• Lateral surface is related to submandibular fossa (on mandible), medial pterygoid (insertion) and facial artery.
• Medial surface is related to mylohyoid, hyoglossus and styloglossus muscles.

Deep part:

• It lies on the hyoglossus muscle deep to mylohyoid.
• It is related above to lingual nerve, submandibular ganglion; and below to hypoglossal nerve.

Submandibular duct (Wharton’s duct)

• It is 5 cm long duct and runs forwards on hyoglossus, b/w lingual and hypoglossal nerves.
• At the anterior border of the hyoglossus muscle it is crossed by lingual nerve which loops around it.
• It opens into the floor of mouth, on the summit of the sublingual papilla at the side of frenulum of tongue.

BLOOD SUPPLY:

• Arterial supply is by- branches of facial & lingual arteries.
• Venous drainage- by common facial & lingual veins.
• Lymphatic drainage- Submandibular lymph nodes.

NERVE SUPPLY:

• Secretomotor supply is same for submandibular and sublingual salivary glands, through the submandibular ganglion.
• Preganglionic fibers arise from superior salivatory nucleus, and pass successively via sensory root of VII nerve (nerve intermedius)→ facial nerve→ chorda tympani nerve→ lingual nerve→ submandibular gland-> postganglionic fibers → submandibular & lingual glands.