• Mouth or buccal cavity.
• It is formed by cheeks, lips and palate.
• Inside mouth are the teeth, tongue and salivary
• Mouth opens anteriorly to the exterior through
• Mouth opens Posteriorly through fauces into the
• Digestive juice present in the mouth is saliva,
which is secreted by the
FUNCTIONS OF MOUTH:
1. Ingestion of food materials
2. Chewing the food and mixing it with saliva
3. Appreciation of taste of the food
4. Transfer of food (bolus) to the esophagus by
5 . R o l e i n s p e e c h
6 . S o c i a l f u n c t i o n s s u c h a s
s m i l i n g a n d o t h e r e x p r e s s i o n s .
CLASSIFICATION OF SALIVARY
1. Serous Glands:
• mainly made up of serous cells secrete (watery saliva).
• Parotid glands and lingual serous glands are the serous
2. Mucus Glands:
• mainly made up of mucus cells secrete (thick, viscous
saliva with high mucin content).
• Lingual mucus glands, buccal glands and palatal glands.
3. Mixed Glands:
• made up of both serous and mucus cells.
• Submandibular, sublingual and labial glands.
COMPOSITION OF SALIVA:
1. Volume: 1000 mL to 1500 mL of saliva is
secreted per day.
2. Reaction: Mixed saliva from all the glands is
slightly acidic with pH of 6.35 to 6.85
3. Specific gravity: It ranges between 1.002 and
4. Tonicity: Saliva is hypotonic to plasma.
• Mixed saliva contains 99.5% water and 0.5%
1. Preparation of food for swallowing.
2. Appreciation of taste.
3. Digestive function. (Amylase, maltase, lingual
4. Cleansing and protective functions (proline-rich
5. ROLE IN SPEECH.
6. EXCRETORY FUNCTION.
7. REGULATION OF BODY TEMPERATURE.
8. REGULATION OF WATER BALANCE.
REGULATION OF SALIVARY SECRETION:
Function of Parasympathetic Fibers:
1. Stimulation of parasympathetic fibers of salivary glands
causes secretion of saliva with large quantity of water.
2. activate the acinar cells and cause vasodilation.
3. The neurotransmitter is acetylcholine.
Function of Sympathetic Fibers:
1. Stimulation of sympathetic fibers causes secretion of
saliva, which is thick and rich in organic constituents.
2. activate the acinar cells and cause vasoconstriction.
3. The neurotransmitter is noradrenaline.
REFLEX REGULATION OF SALIVARY SECRETION:
1. Unconditioned Reflex:
Not need any previous experience.
Any substance placed in the mouth will secrete
2. Conditioned Reflex:
Needs previous experience.
Presence of food in the mouth is not necessary.
The stimuli for this reflex are the sight, smell,
hearing or thought of food.
EFFECT OF DRUGS AND CHEMICALS
ON SALIVARY SECRETION:
• Substances which increase salivary secretion
1. Sympathomimetic drugs like adrenaline and ephedrine.
2. Parasympathomimetic drugs like acetylcholine,
pilocarpine, muscarine and physostigmine.
• Substances which decrease salivary secretion
1. Sympathetic depressants like ergotamine and dibenamine.
2. Parasympathetic depressants like atropine and
3. Anesthetics such as chloroform and ether stimulate the
secretion of saliva. However, deep anesthesia decreases
the secretion due to central inhibition.