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    Related Topics

    From Digestive System

    Vermiform Appendix
    Worm-like appendage of the cecum.
    Rectum
    Straight section of the colon leading to anus.
    Gingiva
    Gums; soft tissue covering the bones of the jaw.
    Anal Canal
    Terminal part of the large intestine.
    Pyloric Sphincter
    Regulates passage of chyme from stomach to duodenum.
    Accessory Pancreatic Duct
    Secondary duct emptying into duodenum.
    Head of Pancreas
    Widest part of pancreas nestled in duodenum.
    Common Hepatic Duct
    Carries bile from liver to bile duct.
    Right Lobe
    Larger functional lobe of the liver.
    Soft Palate
    Muscular posterior part of the roof of the mouth.
    Stomach
    Muscular sac that begins digestion of protein.
    Mesocolon
    Peritoneal fold attaching colon to posterior wall.
    Pylorus
    Distal part of stomach leading to duodenum.
    Teniae Coli
    Longitudinal muscle bands of colon.
    Oral Cavity
    Entry point of the digestive system; includes teeth, tongue, and salivary openings.
    Upper Esophageal Sphincter
    Muscle ring that controls entry into the esophagus.
    Cardia
    Upper opening of the stomach.
    Descending Colon
    Vertical segment of the colon on the left side.
    Parotid Glands
    Largest salivary glands located near the ear.
    Esophagus
    Muscular tube conveying food from the pharynx to the stomach.
    Quadrate Lobe
    Small lobe located between gallbladder and round ligament.
    Cheeks
    Lateral walls of the oral cavity composed of muscle and fat.
    Gallbladder
    Stores and concentrates bile.
    Major Duodenal Papilla
    Opening for bile and pancreatic ducts into duodenum.
    Splenic Flexure
    Bend between transverse and descending colon.

    Submandibular Glands

    Reviewed by our medical team

    Salivary glands beneath the mandible.

    Overview

    The submandibular glands are paired major salivary glands responsible for producing a significant portion of the saliva in the oral cavity. These glands are second in size only to the parotid glands and secrete a mixture of serous and mucous saliva. Their strategic location and ductal architecture make them essential in maintaining oral lubrication, initiating digestion, and protecting oral tissues.

    Location

    The submandibular glands are located in the submandibular (digastric) triangle of the neck. Specifically, they are:

    • Situated beneath the floor of the mouth and inferior to the mandible

    • Wrapped partially around the posterior edge of the mylohyoid muscle, dividing each gland into superficial and deep parts

    • Anterior to the angle of the mandible and close to the facial artery and vein

    Structure

    The submandibular glands are:

    • Mixed glands: Composed of both serous acini (dominant) and mucous acini

    • Approximately 10–15 grams in weight

    • Drained by the submandibular (Wharton’s) duct, which opens at the sublingual caruncle near the base of the tongue

    • Innervated by: Parasympathetic fibers of the facial nerve (CN VII) via the chorda tympani and submandibular ganglion

    • Supplied by: The facial and lingual arteries and drained via accompanying veins

    Function

    The submandibular glands serve multiple essential functions:

    • Saliva production: Contribute approximately 65–70% of resting (unstimulated) salivary output

    • Seromucous secretion: Their saliva is primarily serous (watery and enzyme-rich) with some mucous (thick and lubricating) components

    • Facilitate digestion: Secrete salivary amylase (ptyalin) to begin starch digestion in the mouth

    • Oral hydration: Moistens food, helps with swallowing, and protects mucosal surfaces

    Physiological Role(s)

    The submandibular glands play a continuous and responsive role in:

    • Basal and reflexive secretion: Continuously secrete saliva at rest and increase output in response to taste, smell, and mastication

    • Buffering capacity: Secrete bicarbonate ions to maintain oral pH and neutralize acids

    • Antimicrobial defense: Saliva contains lysozyme, lactoferrin, IgA, and other agents that inhibit bacterial growth

    • Taste perception: Saliva acts as a solvent for tastants and maintains taste bud health

    Clinical Significance

    The submandibular glands are frequently involved in both benign and pathological conditions:

    • Sialolithiasis (salivary stones): Most common in the submandibular glands due to the upward course and mucous nature of Wharton’s duct; may cause pain and swelling during meals

    • Sialadenitis: Bacterial or viral infection of the gland, often secondary to obstruction; presents with tenderness, redness, and pus at the duct opening

    • Ranula: A mucous cyst arising from rupture or blockage of the duct; appears as a bluish swelling in the floor of the mouth

    • Neoplasms: Tumors can develop, though less common than in the parotid; often benign but may be malignant

    • Surgical considerations: Submandibular gland excision may be performed for tumors or recurrent stones; care is needed to preserve the lingual nerve and marginal mandibular branch of the facial nerve

    • Dry mouth (xerostomia): Dysfunction, excision, or radiation damage can reduce saliva and affect oral health and digestion

    Diagnostic tools include ultrasound, sialography, CT/MRI, and fine needle aspiration (FNA) for tumor evaluation. Treatment may be conservative or surgical depending on the underlying condition.

    Did you know? The digestive system absorbs nutrients from food, which are then used by the body to perform various functions.