physiology of saliva

1. Dr.B.H.DAVID LENINSON
1ST Year Pg Oral Medicine & Radiology

2. CONTENTS
 Introduction
 Development
 Anatomy of salivary glands
 Classification of salivary glands
 Nerve supply to salivary glands
 Formation of saliva
 Properties of saliva
 Composition of saliva

3.  Functions of saliva
 Regulation of saliva
 Saliva as diagnostic aid
 Collection of saliva
 Clinical consideration of saliva
 Effects of drugs and chemicals on salivary flow

4. INTRODUCTION
 Human saliva consist of organic and inorganic
components and plays role in mastication, bolus
formation, acts as lubricant, speech, and protects oral
mucosa
 Enzymes in saliva helps in digestion of starches and fat

5. DEVELOPMENT
 The primordia of the glands appear at 7-8th week of IUL
 Minor SG-3rd week of IUL
 Development of duct

6. ANATOMICAL CLASSIFICATION
MAJOR SALIVARY GLANDS
submandibular
Sublingual
Parotid

7. MINOR SALIVARY GLANDS
Lingual mucous
Lingual serous
Buccal
Lingual
Sublingual
Palatal

8. PAROTID

9. SUBMANDIBULAR GLAND

10. SUB LINGUAL

11. MINOR SALIVARY GLANDS
 LABIALAND BUCCAL GLANDS
 GLOSSOPLATINE GLANDS
 PALATINE GLANDS
 LINGUAL GLANDS

12. HISTOCHEMICAL NATURE
SEROUS GLANDS
MUCOUS GLANDS
MIXED GLANDS

13. NERVE SUPPLY TO SALIVARY GLANDS
Parasympathetic
Sympathetic

14. PARASYMPATHETIC FIBRES TO
SUBMANDIBULAR & SUBLINGUAL GLANDS

15. PARA SYMPATHETIC FIBERS TO PAROTID GLAND

16. SYMPATHETIC FIBERS
 Arise from lateral horns of first and second thoracic
segments of spinal cord.
 Fibers leave the cord through the anterior nerve roots
and end in superior cervical ganglion of the
sympathetic chain
 The post ganglionic nerve fibers are distributed to the
salivary glands

17. FORMATION OF SALIVA
 INITIAL FORMATION STAGE
release of calcium
Change in the electro negativity of ca+2 to ca- +ca-
diffusion of Na
net influx creates Nacl

18. MODIFICATION STAGE
Intra lobular ducts reabsorbs NACL
ACTIVAION OF BETA ADRENORECEPTOR
INCREASES INRACELLULAR CAMP
SECREATION OF AMYLASE & PROTEIN GRANULES

19. PROPERTIES
 VOLUME 1 to 1.5 liters
 PH 6.3 to 6.85
 SPECIFIC GRAVITY 1.002-1.012
 TONICITY hypotonic

20. COMPOSITION

21. ORGANIC COMPONENTS
 AMYLASES
 Digestive function
 Hydrolysis of starches
 Acidic nature of saliva

22.  LACTOFERIN
Iron binding protein
Nutritional immunity
 HISTATIN
Anti-microbial & antifungal
von ebner’s glans secretes histatin

23.  CYSTATIN
Inhibit cystin proteases
Act against unwanted proteolysis
LINGUAL LIPASE
secreted by minor SG of tongue
fat digestion
digestion of milk fat in newborn
Hydrophobic nature

24.  SATHERINS & PROLINE RICH-PROTEINS
Maintains enamel integrity
 MUSIN
MG1 AND MG2
Tissue capacity
Lubrication
Aggregation of bacterial cells

25. INORGANIC COMPONENTS
 SODIUM, CHLORINE & POTTASIUM
Osmolality of saliva
 CALCIUM
Super saturated with Ca enhance enamel mineralization
 BICARBONATES
Buffering action of saliva
 FLUROIDE

26. FUNCTIONS
 DEGLUTATION
 APPRECIATION OF TASTE
 DIGESTIVE
 CLEANING & PROTECTIVE
 ROLE IN SPEECH
 EXCRETORY

27. SALIVA AS DIAGNOSTIC AID
 Saliva musin constituents of oral fluid has high
potential for surveillance of general health and
diseases.
 Presence of tumor marker in saliva
 Presence of antibodies to other infectious organism's
 Detection of hepatitis A and B surface antigen
 Neonates presences of IgA for Rota –virus infection

28. HYPOSALIVATION
 Reduction in the secretion of saliva
 Temporary
 Permanent

29. DRY MOUTH
 Loss of salivary function
 Reduction in the volume of secreted saliva
 May occur due to drugs, radiation therapy for head and
neck carcinoma, auto immune disorders
 Temporary relief by sialagogues, sipping of water, ice-
cubes, artificial saliva

30. SJOGREN’S SYNDROME
 Chronic auto immune disorder
 Henrik Sjogren 1933
 Characterized by triad of keratoconjunctivitis, xerostomia,
rheumatoid arthritis.
 Primary
 Secondary

31. ETIOLOGY
 AUTO IMMUNE DISORDER
 HLA-DR3 & HLA-B8
 HLA-DRW52

32. CLINICAL FEATURES
 Female predilection
 Over 40 years
 Dryness of mouth and eyes
 Burning sensation of oral mucosa
 Lymphadenopathy, enlargement of parotid gland
 Purpura, Raynaud's phenomenon
 Myositis.

33. Radiographic features
 Cherry blossom
 branch fruit laden tree

34. Management
 Artificial tears
 Artificial saliva
 Salivary substitutes

35.  Age changes
 Generalized loss of gland parenchymal tissue
 Lost cells are replaced by adipose tissue
 Caries Washes away the acids
 DENTAL EROSIONS
 deficient mineralization of teeth
 low buffering capacity and flow-increase in risk of dental erosions

36.  Hyposalivation leads to retention of food particles
halitosis, gingivitis
 Aphthous ulcers, lichen planus, delayed wound healing,
candidiasis, mucositis
 Disphagia, dysgeusia,glossitis

37. HYPERSALIVATION
 Excess secreation of saliva
 Ptyalism, sialorreha, saialism, sialosis
 Occurs due to
 Decay of tooth, neoplasm of tongue
 Diseases of esophagus stomach, intestine
 Cerebral palsy & mental retardation
 Parkinsonism
 Psycological conditions
 Nausea & vomtings

38. CHORDA TYMPANI SYNDROME
 CHARCTERIZED BY SWEATING WHILE EATING
 CAUSED DUE TO TRAUMA OF NERVE FIBERS
FREYS SYNDROME
 Auriculo temporal syndrome, baillagers syndrome,
dupuy’s syndrome,
 Congenital or acquired due to parotid surgery
 Redness and sweating on cheek area adjacent to ear,
hypersalivation

39. Paralytic secretion of saliva
Parasympathetic nerve to saliva is cut
1st increases for 3 weeks and stops about 6th week

40. EFFECT OF DRUGS AND CHEMICALS ON SALIVARY SECRETION
 Sympathomimetic drugs adrenaline, ephedrine
stimulates salivary secretion
 Parasympathomimetic drugs like acetylcholine,
pilocarpine, muscarine & physostigmine
 Symathetic depressant like ergotamine
 Parasympathetic like atropine inhibit salivary flow

41. References
 Kontis TC, Johns Me. Anatomy and Physiology of the Salivary Glands. Head and Neck
Surgery-Otolaryngology, Second Edition, ed. Byron J. Bailey. Lippincott-RavenPublishers,
Philadelphia, PA. 1998: 531-539.
 Oral medicine Burkit’s 11th edition
 Textbook of medical physiology guyton &hall 9th edition
 Ak.jain text book of phisiology
 Essentials of physiology p.sembulingam 4th eddition
 Chaurasia
 Orbans dental histology