Salivary glands ppt vijji

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Salivary glands ppt vijji

  1. 1. GOOD MORNING
  2. 2. Presented by: M.VIJAYALAKSHMI
  3. 3. Contents: • Introduction • Salivary glands » Classifications » Anatomy » Development » Structure • Composition & Functions • Regulation of secretion • Saliva production » Flow rate • Disorders » Hypo function » Hyper function • Saliva a diagnostic aid • Saliva & age
  4. 4. STRUCTURE OF SALIVARY GLAND
  5. 5. Serous Cell • Stain darkly with haematoxylin and eosin • Rounded nuclei towards the base
  6. 6. Nucleus encodes a message Aminoacid with specific sequence is synthesized These pre proteins contain NH2 terminal called signal sequence
  7. 7. Signal sequence is attached to rough endoplasmic reticulum RER recognizes the signal sequence and crosses with the growing polypeptide chain Newly synthesized protein reaches the cisternal space of RER Protein reaches the golgiapparatus
  8. 8. • Budding vesicles of RER enter from the cis face. vesicles fuses with the golgi saccules proteins are packed in to vacuoles (immature granules) They under go glycosylation and forms mature granule
  9. 9. Mucous Cell • Mucous cells stain very lightly • Completely filled by mucoid material (stains poorly) • This material pushes the nuclei towards the basement membrane • Nuclei are flattened
  10. 10. Myoepithelial cells
  11. 11. SALIVARY DUCTAL SYSTEM
  12. 12. Intercalated duct
  13. 13. STRIATED DUCT
  14. 14. EXCRETORY DUCT
  15. 15. DEVELOPMENT OF SALIVARY GLAND • They originate from oral epithelial buds invading the underlying ectomesenchyme • The origin of epithelial buds Ectodermal in parotid and minor salivary gland Endodermal in submandibular and sublingual glands • The connective tissue stroma and blood vessels origin from the mesenchyme
  16. 16. Gland Location IU life Parotid gland Corner of stomodium 6th week Sub mandibular gland Floor of mouth End of 6th week Sub lingual gland Lateral to sub mandibular primordium 8th week Minor salivary glands Buccal epithelium 12th week
  17. 17. STAGES OF DEVELOPMENT • STAGE I: Bud formation :Induction of oral epithelium by underlying mesenchyme
  18. 18. • STAGE -II Formation and growth of epithelial cord
  19. 19. • STAGE III: Initiation of branching in terminal parts of epithelial cord and continuation of glandular differentiation
  20. 20. • STAGE IV: Dichotomous branching of epithelial cord and lobule formation
  21. 21. STAGE V: Canalization of presumptive ducts.
  22. 22. • STAGE VI: Cytodifferentiation
  23. 23. Connective tissue • Capsule • Septa divides the gland into lobes and lobules
  24. 24. Blood supply
  25. 25. Nerve supply
  26. 26. CLASSIFICATION OF SALIVARY GLANDS • Classification • Major salivary glands • Minor salivary glands • Mucous salivary glands • Serous salivary glands • Mixed salivary glands
  27. 27. Major salivary glands
  28. 28. Parotid gland
  29. 29. Parotid duct • Thick walled • About 5 cm long • Emerges from middle of anterior border • Relations are : • superiorly 1. Accessory parotid gland 2. Upper buccal branch of facial nerve 3. Transverse facial vessels • Inferiorly : The lower buccal branch of the facial nerve
  30. 30. Blood supply • External carotid artery Venous drainage • External jugular vein Nervous supply –(otic ganglion) • Parasympathetic- auriculotemporal nerve • sympathetic- plexus around external carotid artery
  31. 31. Nucleus of origin Inferior salivary nucleus Glossopharyngeal nerve Tympanic branch Tympanic plexus Lesser petrosal nerve Otic ganglion
  32. 32. Submandibular Gland • Situated in anterior part of digastric triangle • Superficial part • Deep part
  33. 33. Submandibular duct • Wharton’s duct passes forward along the superior surface of the mylohyoid adjacent to the lingual nerve.
  34. 34. • Blood supply – facial artery • Venous drainage – common facial or lingual vein • Nerve supply – Parasympathetic –submandibular ganglion – Sympathetic –plexus around the facial artery – Sensory – lingual nerve
  35. 35. Nucleus of origin Superior salivary nucleus facial nerve Chorda tympani Lingual nerve Submandibular gland
  36. 36. Sublingual gland • Smallest of the three glands.
  37. 37. • Blood supply – Lingual and submental arteries • Venous drainage – common facial or lingual vein • Nerve supply – Parasympathetic – submandibular ganglion – Sympathetic – plexus around the facial artery – Sensory – lingual nerve
  38. 38. Minor salivary glands • Labial and buccal salivary glands • Glosso palatine salivary glands • Lingual salivary glands
  39. 39. COMPOSITION OF SALIVA
  40. 40. Inorganic components
  41. 41. Organic components of saliva Other substances • Blood group substances, sugars, steroid hormones, amino acids, ammonia, urea
  42. 42. SALIVA SECRETION • The formation of saliva occurs in two stages. 1. In the first stage - primary saliva. 2. In the second stage, the primary saliva is modified.
  43. 43. Salivary secretion:two step model
  44. 44. • Ductal modification of primary saliva: • Occurs principally through reabsorption & secretion of electrolytes • The luminal & basolateral membrane have abundant transporters that function to produce a net reabsorption of Na⁺ & Cl⁻ resulting in formation of hypotonic final saliva • The final electrolyte composition of saliva varies depending on the salivary flow rate
  45. 45. Control of secretion • It is through the activity of the ANS. Sympathetic and Para sympathetic postganglionic fibres secretory, myoepithelial cells, intercalated ducts, straited ducts
  46. 46. • 2 types of innervation are seen intra epithelial{hypolemmal} sub epithelial{epilemmal} • Stimulus secretion coupling ?
  47. 47. • Stimulation of alpha , beta and cholinergic receptors causes ? • Substance P and vasoactive intestinal polypeptides
  48. 48. • Intercellular junctions of salivary glands Gap junctions
  49. 49. • Secretory cells are stimulated. protein secretion occurs in two pathways 1. primary pathway (main pathway) 2. secondary pathway. Transcytosis – from basolateral to apical cell
  50. 50. Saliva & Age: • With age, a generalized decrease in saliva Decreased parenchymal tissue occurs/ medication • Resting salivary secretion is in the normal range,the volume of saliva produced during stimulated secretion is less than normal.
  51. 51. Functions of saliva • Protection : prevents dessication washing action lubrication buffering antibacterial defensive
  52. 52. • Other functions are taste perception speech tissue repair digestion excretory mastication and deglutition
  53. 53. Saliva production – Differential saliva production by glands • Unstimulated salivation (Salivary gland at rest) – 1.5 Liters produced per day (basal rate) – Major salivary glands: 90% of saliva produced – Submandibular and sublingual glands: 70% of saliva • Stimulated salivation – Saliva production increases 5 fold – Parotid gland produces majority of saliva
  54. 54. Flow rate (ml/min) WHOLE PAROTID SUBMANDIBULAR RESTING 0.2-0.4 0.04 0.1 STIMULATED 2.0-5.0 1.0-2.0 0.8 pH 6.7-7.4 6.0-7.8
  55. 55. 0.0 0.1 0.2 0.3 0.4 0.5 20-39 yr 40-59 yr > 60 yr ml/min Age Flow Rate of Saliva unstimulated stimulated
  56. 56. Clinical considerations
  57. 57. Xerostomia • Unstimulated salivary flow - less than 0.12 to 0.16 ml/minute Pale Fisured Tongue Due To Severe Dry Mouth Moderate Xerostomia
  58. 58. Severe Dry Mouth (Strawberry Tongue)
  59. 59. MUCOCELE
  60. 60. Ranula
  61. 61. Nicotiana stomatitis
  62. 62. ptyalism
  63. 63. Sialolithiasis
  64. 64. Tumours of the salivary glands • Benign tumours • Malignant tumours
  65. 65. IMAGING MODALITIES : • Computed Tomography • Magnetic Resonance • Ultrasound sonography • Sailograms
  66. 66. IMAGING MODALITIES contd… • ADULTS : • CT – inflammatory disorders • MR – evaluation of tumors • CHILDREN: • Ultrasound – inflammatory or superficial • MR- deeper masses
  67. 67. CT of salivary gland
  68. 68. MRI
  69. 69. ULTRASONOGRAPHY
  70. 70. SIALOGRAPHY
  71. 71. • Scintigraphy
  72. 72. • References 1. orbans oral histology and embryology (13th edition) 2. Tencates oral histology 3. orbans oral histology and embryology(11th edition) 4. garants oral cells and tissues 5. burkets oral medicine 6. google search 7. Chaurasia human anatomy head and neck
  73. 73. • Thank u

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