The document discusses the physiological anatomy of salivary glands and their composition. It lists the major salivary glands as the parotid, submaxillary, and sublingual glands. The minor salivary glands include the labial, pharyngeal, lingual, and palatine glands. Salivary glands are classified as serous, mucous, or mixed based on their secretions. The structure of salivary glands includes acini that secrete isotonic fluid into ducts, where the fluid becomes hypotonic through active transport processes in the ductal cells. Saliva is composed mainly of water but also contains electrolytes, enzymes, mucus, and

1. Physiological Anatomy of
Salivary Gland and its
Composition
Dr Aqsa Jabeen

2. LEARNING OBJECTIVES
By the end of this lecture students of 2 year MBBS will be able to
• List the major and minor salivary glands
• Classify salivary glands on the basis of secretions
• Describe the structure of salivary gland
• Explain the composition of saliva
• Describe the mechanism of salivary secretion

3. SALIVARY GLANDS
• MAJOR SALIVARY GLANDS
i. Parotid glands
ii. Submaxillary or submandibular glands
iii. Sublingual glands
• MINOR (SMALL) SALIVARY GLANDS
i. Labial
ii. Pharyngeal
iii. Lingual
iv. Palatine

4. SALIVARY GLANDS

5. TYPES OF SECRETIONS
• Serous secretion
• PTYLAIN.. Alpha amylase for starch digestion
• Mucous secretion
• MUCIN…lubrication

6. ON THE BASIS OF SECRETION
• SEROUS
• Parotid gland
• MUCOUS
• Buccal
• MIXED
• Submandibular
• Sublingual gland

7. STRUCTURE OF SALIVARY GLAND
• Major salivary glands are paired structure
• Rate of secretion 1L/day
• Structure
• ACINI
• SALIVARY DUCTS

8. ACINUS
• Small group of cells which surround a central globular cavity
• Central cavity of each acinus is continuous with the lumen of
the duct.

10. SALIVARY DUCTS
• Fine duct draining each acinus is called intercalated duct
• Striated duct
• Excretory duct of the gland

11. COMPOSITION OF SALIVA
• Water 99.5%
• ELECTROLYTES
• LOWER ..NA AND CL
• HIGHER ..K AND HCO3
• PROTEINS
• AMYLASE
• LINGUAL LIPASE
• KALLIKLERIN
• MUCUS
• LYSOZYME

12. FORMATION OF SALIVA
First stage …Acini
Isotonic secretion
Second stage . . . Salivary ducts
Hypotonic secretion

13. ACINAR CELL SECRETION
• Primary secretion
• Isotonic
• Ptyalin , mucin , lipase in a solution of ions with concentration
not different ECF

15. ROLE PLAY OF PRIMARY SALIVA SECRETION

16. DUCTAL SECRETION
1. Active reabsorption of sodium in ductal cells
2. Active secretion of potassium into lumen
3. Passive reabsorption of chloride to balance electronegativity
4. Bicarbonate ions are secreted by ductal epithelium

18. ROLE PLAY OF SALIVA SECRETION

19. SUMMARY
• List the major and minor salivary glands
• Classify salivary glands on the basis of secretions
• Describe the structure of salivary gland
• Explain the composition of saliva
• Describe the mechanism of salivary secretion