3. Biochemical composition of saliva 1
Dr Sara Amjad

4. Introduction of Gastro Intestinal tract
Every cell of living system needs energy
Unicellular organisms:
Exists in the sea of nutrients
Can satisfy their nutritional need just by
Proteins present at the cell membrane

5. Multi cellular organisms
In multi cellular organisms, a groups of cells converted to a tissue , to perform specific function
A number of systems are evolved in vertebrates including humans
To provide nutrients to all the systems The Gastro intestinal tract is accounted for extraction of nutrients from the food

6. The Food
The most of the food we eat are macromolecules , it can not cross the cell membrane easily
so it must be converted to monomers
Gastrointestinal tract is to make the food in absorbable form by help of chewing and mixing with various enzymes in mouth to small intestine

7. Digestive system

8. Components of GIT Oral Cavity Oesophagus Stomach Duodenum Jejunum
Various parts
Glands includes
Oral Cavity
Salivary glands
Oesophagus
Gastric glands
Stomach
Pancreas
Duodenum Jejunum
Liver and biliary system
Ileum
Intestinal glands
Jejunum
Endocrine glands
Cecum
Enteric nervous system
Colon
Circular smooth muscles
Rectum and anal canal
Longitudinal muscles

9. Saliva Colorless Viscoelastic Various biologic functions
In adult total volume ml/day
Specific gravity
Average pH 6.75

10. Structure of salivary Glands

11. Major salivary glands
Parotid
Sub maxillary
Sublingual

12. Minor salivary glands
Labial
Lingual
Buccal
Palatal

13. 95 percent secretion
5 percent secretion
Submandibular glands 60 percent
Parotid glands percent
Sublingual glands percent

14. During sleep parotid and sublingual glands do not secrete saliva , submandibular glands secrete saliva to keep oral cavity and tongue wet and clean

15. Types of salivary gland cells
Terminal secretory units
Three types of cells
Serous
Mucus
Myoepithelial cells

16. Parotid gland…serous gland
Sublingual gland ….mucous gland
Submandibular gland….mixed gland

18. Formation of saliva Primary secretion or primary saliva
Terminal secretary unit
Intercalated ducts
Striated ducts
excretory duct
oral cavity

19. Composition of primary saliva
primary saliva(intercalated duct)
Saliva (oral cavity)
Isotonic fluid
Hypotonic fluid Na K
HCO3

20. Primary saliva lacks lysozyme, lactoferrin and kallikrein
Difference in composition
Electrolyte exchange
Secretion of proteins
Striated ducts secrete K in and actively reabsorb Na from primary secretion

21. Striated duct cells also secrete kallikrein and glycoprotein's
Intercalated ducts secrete antibacterial proteins ,lysozyme and lactoferrin
Water secretion at terminal secretary units

23. Concentration Gradient
Proteins
Na+& Cl- K+
©Reeves 2013
Hypotonic
Final Saliva
Concentration Gradient
Concentration Gradient
H2O
Water and electrolytes
Isotonic
Primary Saliva

24. Factors Stimulating Salivary Secretion
Psychic stimuli
Chemical stimuli
Mechanical stimuli

25. salivary secretion
Resting level of salivary secretion is to 0.4ml/min
Stimulus 1 to 3 ml/min

27. Regulation Of Saliva
Secretion of saliva is under autonomic nervous system
Salivary gland are innervated by both parasympathetic (cholinergic) and sympathetic (adrenergic) nerve fibers
Neurotransmitters at neurosecretory junction are acetylcholine and nor epinephrine respectively

28. Cholinergic…..watery saliva
Adrenergic……thicker saliva

32. BIOMEDICAL IMPORTANCE OF SALIVA

33. Lesion in cavity…excessive salivation Opiorphin …pain killing substance Diabetes mellitus …enlargement of parotid gland Sjogren,s syndrome…little secretion Cushing's syndrome …Na content increases

34. Antihypertensive drugs, antidepressants drugs causes xerostomia
Hypo secretion causes dental caries

35. Artificial saliva
Saliveze , xialine 1, xialine 2 Composition of artificial saliva Water Electrolytes Mucoadhesive polymer No digestive and antimicrobial enzymes

36. Diagnostic significance of saliva
Isolation of virus
Detect presence of antibodies against virus causing AIDS, measles, Hepatitis A, B and C
Sialochemistry helps in determination of ovulation time