Salivary secretionn from GASTROINTESTINAL PHYSIOLOGY

1. SALIVARY GLANDS
AND
THEIR SECRETION

3. PAROTID GLAND

4. SUB MANDIBULAR GLAND
 Inferior to the body of the Mandible
 Produce most of the saliva (60-70 %)
 Ducts open through a Papilla in the floor of the mouth
 lateral to the Lingual Frenulum

5. SUBLINGUAL GLAND
 Inferior to the tongue
 Internal to the Oral cavity Mucosa
 each gland has multiple tiny sublingual ducts
 Open on to the Inferior surface of the oral cavity
 Posterior to the Submandibular duct papilla
 contribute on 3-5% of total saliva

8. TYPES OF CELLS IN SALIVARY GLANDS
1.Mucous cells
Mucinogen
granules
Lubrication
and
Protection
Secretions
contains
“Mucin”
2. Serous Cells
Zymogen
Granules
Ptyalin
Precursors
Watery ,
contains SA
Digestion of
Starch
,maltose

10. COMPOSITION

11. FLOW RATE OF SALIVA

12. FUNCTIONS

13. MECHANISM OF FORMATION OF SALIVA
1. Primary secretion
2. Modification of saliva

14. MECHANISM OF FORMATION OF SALIVA
PRIMARY SECETION
•FORMED BY TRANSUDATION (Pressure filtration)
•ISOTONIC TO PLASMA
•MODIFIED AS SOON AS THEY SECRETED
IMP:
EFFECT OF ALDOSTERONE ON DUCT CELLS

17. SYMPATHETIC STIMULATION
Sympathetic nerves (NE: Nor Epinephrine)
NE
Via β-
Receptors
↑ cAMP
Excytosis of
Enzymes
↑ Secretion
NE
↑ Ca2+
↑ Secretion

18. REFLEX REGULATION OF SALIVARY SECRETION

19. PHYSIOLOGICAL CONDITIONS

20. CEPHALIC PHASE SECRETION OF SALIVA BEFORE
ENTRY OF FOOD
CONDITIONAL REFLEX
BUCCAL PHASE PRESENCE OF FOOD IN THE
MOUTH [(+) BUCCAL
RECEPTORS]
UNCONDITIONAL REFLEX&
PARTIALLY REGULATED BY
APETITE CENTRE
OESOPHAGEAL PHASE PASSING OF FOOD THROUGH
OESOPHAGUS
STIMULATION OF SALIVARY
GLANDS
GASTRIC PHASE PRESENCE OF FOOD IN
STOMACH
IRRITANT FOODS IN
STOMACH (VOMITING)
INTESTINAL PHASE FOOD IN INTESTINE IRRITANT FOOD IN UPPER
INTESTINE
PHASES OF SALIVARY SECRETION

21. PHASES OF SALIVARY SECRETION
Cephalic Phase
Food
(Before entering)
Condition reflex
(Sight, Smell etc.,)
Secretion of Saliva

22. GASTRIC PHASE
Food (Mouth)
(+) Buccal Receptors
Secretion of Saliva
 An Unconditioned reflex.
 Partially regulated by Appetite Centre.

23. Esophageal
Phase
Food passing
through
Esophagus
(+) Salivary
Glands
Gastric Phase &
Intestinal Phase
Presence of Food in
Stomach& Intestine
(Irritants)
salivation before
Vomitting
ESOPHAGEAL PHASE GASTRIC AND INTESTINAL
PHASES

24. APPLIED PHYSIOLOGY
1. Salivary Duct Calculus: Blockage of Ducts
2. Xerostomia: Dryness of mouth due to decreased ↓ salivary
Secretion. Eg: Radiation Therapy.
3. Sialoliths: Crystalized Saliva deposits
4. Sialadenitis: Bacterial infections
5. Viral Infections: Mumps
6. Sialorrhoea: ↑ Salivary secretion