Salivary glands

• • Salivary glands are exocrine glands that produce saliva.
  • There are 3 large named pairs of salivary glands and multiple unnamed glands in submucosa of oral cavity
• Parotid gland

  • Largest salivary gland; triangular shape
  • Formed entirely by serous acini
  • Has an accessory part: small part separated from main gland
• Nerve supply of parotid gland

  • Parasympathetic: inferior salivary nucleus of glossopharyngeal nerve→ tympanic nerve→tympanic plexus→lesser petrosal to optic ganglion→postganglionic fibers runs in auriculotemporal nerve
  • Sympathetic: from plexus around external carotid
• •Salivary glands are two groups

  • major salivary glands: Parotids, sublingual and submandibular glands. They are compound tubuloalveolar glands. Their secretion is regulated by nervous reflexes.
  • The minor salivary glands: buccal, labial, lingual&palatine glands. They are simple branched tubuloalveolar glands. They secrete continuously to moisten and lubrificate oral cavity
• Structure of major salivary glands

  I- Stroma: CT capsule + CT septa: that divide the gland into lobes and lobules.

  • Reticular fibers: form a network supports the parenchyma.
  • Parenchyma: Secretory acini: 3 types; serous, mucous and mixed acini.
  • Duct system: interlobular, interlobar, main duct
  • Myoepithelial cells
• Structures passing through parotid gland

  • Facial vein: most superficial; it gives 2 branches before it enters gland and 5 branches within the gland (temporal, zygomatic, buccal, mandibular, cervical)
  • Retromandibular vein formed by superior temporal and maxillary veins
  • External carotid: gives maxillary and superficial temporal arteries
• Two major ducts arising from the parotid gland unite within the substance of the organ to form the parotid duct of Stensen. It opens into vestible of mouthb on a small papulla opposite to second maxillary tooth
• Blood supply of parotid gland

  • Arterial supply: external carotid artery & its branches.
  • Venous drainage: retromandibular vein.
  • Lymphatic drainage: parotid (preauricular) & thence to upper group of deep cervical lymph nodes.
• Main salivary gland

  Z

  
• Saliva

  • Mostly water (>90%)
  • mucin, glycoprotein
  • IgA antibody
  • lysozymes
  • lactoferrin: prevents bacterial growth
  • proteins that protect teeth
  • important part of innate immunity. Enzymes( alpha amylase and lingual lipase)