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Salivary Glands. Prof. Dr. Thanaa Saad El-Din. Major Salivary Glands. The Parotid Glands The Submandibular Glands The Sublingual Gland. Parotid Gland. The superficial portion is located in front of the external ear, while the deeper part fills the retro-mandibular fossa
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Salivary Glands Prof. Dr. Thanaa Saad El-Din
Major Salivary Glands • The Parotid Glands • The Submandibular Glands • The Sublingual Gland
Parotid Gland • The superficial portion is located in front of the external ear, while the deeper part fills the retro-mandibular fossa • The main duct (Stensen's duct) opens into the oral cavity on the mucosa of the cheek opposite the maxillary second molar. Usually a small papilla marks the opening.
Histologically • It is a compound tubulo-alveolar gland • It has a well developed capsule • It is purely serous in the adult but contains few mucous alveoli in the newborn infant. • The intercalated ducts are long and branching. The striated ducts are also long.
Submandibular Gland • The greater part of the submandibular gland is behind and below the free border of the mylohyoid muscle. A tongue-like extension of the gland usually lies above the mylohyoid muscle. • (Wharton's duct) opens on the summit of a papilla at the side of the lingual frenum in the floor of the mouth.
Histologically As it is predominantly serous, it is formed of serous acini with few mucous acini capped by demilunes of serous cells. • The intercalated ducts are short, and the secretory striated ducts are very long. • The connective tissue capsule and septa are less developed than in the parotid
The Sublingual Gland • It is located in the floor of the mouth, in the sublingual fold. It is a composed of one larger and several smaller glands. • The main duct of the large sublingual gland (Bartholin's duct) opens into the oral cavity with or near, but independently from, the submandibular duct. The ducts of the smaller sublingual glands are 8 to 20 in number, and most of them open independently on the sublingual fold.
Histologically • As it is predominantly mucous, it is formed of mucous acini, and the demilunes are seen on some them. Pure serous alveoli are rare • The connective tissue capsule is absent; the septa are better developed than in the parotid and submandibular I.e., thick septae. • The intercalated ducts are absent, and the secretory striated ducts are very short
Nerve supply of major salivary glands • Sensory fibers to all glands: through the 5th cranial nerve (trigeminal). • Sympathetic vasoconstrictor fibers to all glands: derived from the superior cervical sympathetic ganglion. • Parasympathetic vasodilator fibers: • For the parotid from the 9th cranial nerve (glosso-pharyngeal), via the otic ganglion • For the submandibular and sublingual glands from the 7th cranial nerve (facial), through the chorda tympani, via the submandibular ganglion.
Minor Salivary Glands • The minor salivary glands are located beneath the epithelium in almost all parts of the oral cavity. • They consist of several small acini. • They open through short ducts. • They spontaneously secrete saliva. • They lack a distinct capsule, instead supported by the connective tissue of the submucosa or muscle fibers of the tongue or cheek
Minor Salivary Glands A) Labial and Buccal glands B) Glosso-palatine Glands C) Palatine glands D) Lingual glands
Labial and Buccal Glands • The labial and buccalglands are pure mucous glands. • The labial glands are packed in the submucosa near the inner surface of the lips. • The buccal glands are the continuation of the labial glands. • Some buccal glands are found on the surface of the buccinator muscle and between its bundles. • The buccal glands that lie near the opening of the parotid duct and drain into the 3rd molar region are termed the molar glands.
Glosso-palatine Gland • The glosso-palatine glands are pure mucous glands. • They are principally localized to the region of the isthmus in the glosso-palatine fold, but may extend into the glands of the soft palate.
Palatine Glands • Glands of hard palate • They are approximately 250 glands • They are found in the submucosa of the postero-lateral region • They are merging with those of the soft palate • Glands of soft palate • They are approximately 100 glands • They aggregate in the submucosa between the mucosa and palatal musculature • Glands of uvula • They are approximately 12 glands • They are in the submucosa • The palatine glands are pure mucous glands. Their excretory ducts course through the lamina propria. Their openings on the palatal mucosa are large.
Glands of the Tongue The anterior lingual glands (glands of Blandin & Nuhn). • They are located near the apex of the tongue. • The anterior portion are chiefly mucous, while the posterior portions are mixed. • The ducts open on the ventral surface of the tongue near the lingual frenum, approximately 5 small ducts (because these glands are embedded within the musculature of the inferior aspect of the tongue). The posterior lingual glands • posterior lingual (Weber glands):They are pure mucous, located lateral and posterior to vallate papillae. Their ducts open into the dorsal surface of the tongue. • posterior lingual (Von Ebner): They are pure serous, located extensively between the muscles of the tongue below circumvallate and foliate papillae and their ducts open into the trough of the vallate papilla.
