CorpusHuman Anatomy
DigestiveGland

Submandibular gland

Glandula submandibularis

The submandibular gland is a walnut-sized mixed (mainly serous) gland in the submandibular triangle. It produces about two-thirds of unstimulated saliva.

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Overview

Share of resting saliva≈65–70%
Duct length≈5 cm

The gland hooks around the posterior free border of mylohyoid. Its larger superficial part lies below mylohyoid in the submandibular (digastric) triangle. Its smaller deep part lies above mylohyoid in the floor of the mouth, alongside hyoglossus.

The submandibular (Wharton) duct, about 5 cm long, leaves the deep part and runs forward between mylohyoid and hyoglossus and then genioglossus. It opens on the sublingual papilla (caruncle) beside the lingual frenulum. The lingual nerve has an intimate "double crossing" relation with the duct: it passes lateral to the duct, then loops beneath it, then rises on its medial side. This puts the nerve at risk during duct and gland surgery.

The facial artery grooves the deep posterior aspect of the gland. The facial vein and the marginal mandibular branch of VII run superficial to it.

Location

Submandibular triangle of the neck, below the body of the mandible, partly wrapping around the posterior border of mylohyoid.

Parts & subdivisions

  1. Superficial part
    Larger part below mylohyoid. Palpable bimanually between a finger in the mouth and a finger on the neck.
  2. Deep part
    Small part above mylohyoid, on hyoglossus, from which the duct arises.
  3. Submandibular duct (Wharton)
    About 5 cm long. Runs forward in the floor of the mouth and opens at the sublingual caruncle.

Anatomy

Innervation

Parasympathetic pathway: superior salivatory nucleus → facial nerve (VII) → chorda tympani (crosses the middle ear, leaves via the petrotympanic fissure) → joins the lingual nerve (V3) → submandibular ganglion (synapse; hangs from the lingual nerve on hyoglossus) → gland. Sympathetic fibres arrive via the plexus on the facial artery.

Arterial supply

Submental and glandular branches of the facial artery; the lingual artery.

Venous drainage

Facial and lingual veins.

Lymphatic drainage

Submandibular nodes, which lie on and within the gland, draining to the deep cervical nodes.

Relations

Lateral: submandibular fossa of the mandible, medial pterygoid and the facial artery. Superficial: skin, platysma, facial vein and the marginal mandibular nerve. Medial (deep part): hyoglossus with the lingual nerve, submandibular ganglion and hypoglossal nerve.

Histology

Mixed gland, mainly serous acini, with mucous tubules capped by serous demilunes. Its striated ducts are particularly long and well developed.

Function

  • Produces about 65–70% of unstimulated (resting) saliva, which is seromucous.
Secretions

Mixed saliva, mainly serous with some mucous acini and serous demilunes. It is more viscous and richer in calcium than parotid saliva.

Clinical significance

Submandibular stones

The commonest site of salivary calculi (about 80–90%). Swelling and pain occur at mealtimes ("salivary colic"). A stone may be felt in the floor of the mouth or seen on imaging. It can be removed through the duct, or the gland can be excised.

Nerves at risk in submandibular gland excision

The marginal mandibular branch of VII is at risk superficially (drooping of the corner of the mouth), the lingual nerve deep and above (loss of sensation and taste over the anterior tongue), and the hypoglossal nerve deep and below (tongue weakness).

Compiled from standard anatomy and physiology references — see the Digestive System sources. For education only; not medical advice.