Saliva

Question 1

What is Saliva?

Saliva is mostly _______% water and the ____ components make up _____________.

The _____-rich secretions of the salivary glands contain a milieu of _____ _____, ______, _____, ____ elements, and usually contains incredibly high numbers of_____.

Ironically, it is also the tooth’s _____ _____against ____ ____.

It is a symbiotic ecology unto itself.

Answer 1

Saliva is mostly 99.5% water and the functional components make up only a fraction of the volume. The protein-rich secretions of the salivary glands contain a milieu of antibacterial enzymes, immunoglobulins, lubricants, inorganic elements, and usually contains incredibly high numbers of bacteria. Ironically, it is also the tooth’s first defense against cariogenic pathogens. It is a symbiotic ecology unto itself.

Question 2

~ The Functions of Saliva ~ Categories

_____

____ _____

_____

Answer 2

Protective

Food Related

Communications

Question 3

Protective

L_____: W____, M____, ____-rich _____ coat ____ of ____ ___, ____ , and____

A____ A______ A____: Salivary ______ (e.g L____, L_____,L____, M____): H____ , C____, S_________,______-rich ____

M____ I___: M____, E____ , W____

L_____,C_____: W_____

B_____ C____: B____ and P____, P_____

R_____: C ____, P____, ____-rich_____

LAMB LR

Answer 3

I. Protective
Lubrication: Water, mucins, proline-rich glycoproteins coat surfaces of oral mucosa, throat, and food

Antibacterial, Antifungal, Antiviral: Salivary proteins (e.g lysozyme, lactoferrin, lactoperoxidase, mucins): histatins, cystatins, secretory IgA, proline-rich glycoproteins

Mucosal integrity: Mucins, electrolytes, water

Lavage, cleansing: Water

Buffering Capacity: Bicarbonate and phosphate, proteins

Remineralization: Calcium, phosphate, proline-rich glycoproteins

Question 4

Speaker Notes:

Specifically, this table outlines the salivary components involved in the “protective” function
of saliva. The salivary glands provide lubricatory molecules that coat food and the soft and
hard oral tissues. Lubrication allows food to travel easily through the digestive system and provides smooth tissue surfaces with minimal friction. Without lubrication, food becomes impacted around the teeth, making eating difficult and unpleasant, and increasing ___ ___.

Saliva also contains antifungal and antiviral systems. Antibodies (like ____) can directly neutralize _____. Mucins are also effective ____molecules.

Mucins are important in the control of ______ of the mucosal surfaces. The presence of salivary ___ can limit penetration of various potential___ and ____ in foods and beverages, as well as potentially hazardous agents from____ _____and other sources. Mucins, in combination with ____ AND ____, act as natural “____ _____” that helps maintain oral tissues in a _____ state, thus maintaining mucous membrane integrity.

Water, IgA and proline provide an oral “cleansing” and “lavage” function. This physical flow
of saliva constantly removes __________.

Bicarbonate and phosphate ions and proteins assist in the achievement of oral ______
and maintenance of a specific pH through buffering action on strong oral acids and bases.

Teeth are remineralized through the deposition of ___, ___ and ____.

Answer 4

Speaker Notes:

Specifically, this table outlines the salivary components involved in the “protective” function
of saliva. The salivary glands provide lubricatory molecules that coat food and the soft and
hard oral tissues. Lubrication allows food to travel easily through the digestive system and provides smooth tissue surfaces with minimal friction. Without lubrication, food becomes impacted around the teeth, making eating difficult and unpleasant, and increasing plaque formation.

Saliva also contains antifungal and antiviral systems. Antibodies (like secretory IgA) can directly neutralize viruses. Mucins are also effective antiviral molecules.

Mucins are important in the control of permeability of the mucosal surfaces. The presence of salivary film can limit penetration of various potential irritants and toxins in foods and beverages, as well as potentially hazardous agents from tobacco smoke and other sources. Mucins, in combination with electrolytes and water, act as natural “water proofing” that
helps maintain oral tissues in a hydrated state, thus maintaining mucous membrane integrity.3

Water, IgA and proline provide an oral “cleansing” and “lavage” function. This physical flow
of saliva constantly removes potentially harmful bacteria. 3

Bicarbonate and phosphate ions and proteins assist in the achievement of oral homeostasis
and maintenance of a specific pH through buffering action on strong oral acids and bases. 3,4

Teeth are remineralized through the deposition of calcium, phosphorus and stathrin. 4

Question 5

Food Related FCNS

________ for ____ : W M and -__rich

_____: A___ R____ ,___

_____: W____ G____ (______)

Answer 5

Preparation for digestion Water, mucins, proline-rich glycoproteins

Digestion Amylase, ribonuclease, lipase

Taste Water, gustin (zinc-binding salivary protein)

Question 6

Communications

____: ____, ____

Answer 6

Speech Water, mucins

Question 7

Speaker Notes

Saliva is an integral component for preparing food for digestion. Major salivary functions include ____ formation and digestion by the salivary enzymes ____, ____, and ____.

Saliva also enhances ___ and ____

Finally, the lubrication from water and mucins assists in the ability to speak.

Larger taste buds have _____ _____ _____

Answer 7

Speaker Notes:

Saliva is an integral component for preparing food for digestion. Major salivary functions include bolus formation and digestion by the salivary enzymes amylase, ribonuclease, and lipase. 4

Saliva also enhances taste and swallowing.

Finally, the lubrication from water and mucins assists in the ability to speak.

Larger taste buds have small salivary glands

Question 8

The Biological Necessity of Saliva ~ LCC

SH PP STD LCC

Answer 8

•Lubricating and moistening of food for swallowing
•Temperature regulation of solid foods & liquids.
•Solubilizing material so it can be tasted
•Initiating digestion
•Preventing dental caries
•Maintaining pH of upper GI
•Maintaining health of oral mucosa
•Preventing opportunistic infections by keeping
microflora balance
•Speaking
•Cleansing of mouth and clearing the esophagus

Speaker Notes:

Long before there were toothbrushes, fluoride toothpastes and dental floss, the evolutionary process created protective mechanisms in the mouth for self-
defense against the hundreds of species of microorganisms and their 50 billion
(or more) descendants that make their home in the mouth.

The major responsibility for the defense of the mouth rests with the salivary glands. Saliva’s multi-dimensional functions include providing protection of the soft and hard oral tissues. Saliva also plays a pivotal role in the processes of alimentation and communication, which are most often taken for granted until they are impaired.

Question 9

Saliva is Produced by

Answer 9

GLANDULAR EPITHELIUM

Question 10

GLANDULAR EPITHELIUM

Glands are special types of cells, which are specialized to _____ _____ to be used _____ (where). Glands are classified according to their ____ of ____.

Exocrine Glands – Secrete their products via ___ onto the _____ (or epithelial) surface. These glands are highly specialized ____ cells and thus are classified as ____ ____.

Answer 10

Glands are special types of cells, which are specialized to produce products to be used elsewhere in the body. Glands are classified according to their mechanism of secretion.

Exocrine Glands – Secrete their products via ducts onto the apical (or epithelial) surface. These glands are highly specialized epithelial cells and thus are classified as glandular epithelia.

Question 11

Exocrine Glands

Exocrine glands are glands whose secretions pass into a ____ of _____that lead ultimately to the ____ of the body.

So the ____ surface of the glands and the ____ that drain them are topologically _____________.

Answer 11

Exocrine glands are glands whose secretions pass into a system of ducts that lead ultimately to the exterior of the body. So the inner surface of the glands and the ducts that drain them are topologically continuous with the exterior of the body (the skin).

Question 12

Mono-Ductal Systems
____ glands - Glands of this type have an _____ duct into which the cells secrete.

Each secretory portion empties__________________.

In the oral cavity, the ______________ are a prime example of mono ductal glands.

Answer 12

Simple glands - Glands of this type have an unbranched duct into which the cells secrete. Each secretory portion empties separately on an epithelial surface. In the oral cavity, the minor salivary glands are a prime example of mono ductal glands.

Question 13

Poly-Ductal Systems

______ glands - These glands have a ______ duct system.

Secretory portions empty into_______________, which, in turn, drain into___ ______.

Collectively these entities form the _______.

Answer 13

Compound glands - These glands have a highly branched duct system. Secretory portions empty into an elaborate branched duct system, which, in turn, drain into larger ducts. Collectively these entities form the major salivary glands.

Question 14

Examples

Answer 14

Slide 13

Question 15

These Specialized Epithelial Tissues
Combine to Form

Answer 15

the Major and Minor Saliva producing Glands of the Oral Cavity

Question 16

What Is Whole Saliva?

It is a _____ ____ secretion from the ____ and ____ salivary glands of the mouth.

Major salivary glands: Major glands ___ their secretions through a ____ ___into the mouth

Minor salivary glands: Minor glands ___ their secretions _____ (mono-ductal)

Salivary glands are classified by ___, ____, and ____.

The major glands are ____ and alter _____-____ saliva via _____ pathways in the ____.

Minor glands are found on the _____, _____ _____ _____ ___ _____surfaces just___ and within the ___ ____, unencapsulated and within short duct systems.

Answer 16

It is a composite exocrine secretion from the major and minor salivary glands of the mouth.

Major salivary glands: Major glands push their secretions through a main duct into the mouth

Minor salivary glands: Minor glands empty their secretions directly into the mouth (mono-ductal)

Salivary glands are classified by size, location, and histology. The major glands are paired and alter post-secretion saliva via reabsorption pathways in the ducts. Minor glands are found on the labial, lingual, palatal, buccal, glossopalatine, and retromolar surfaces just below and within the mucous membranes, unencapsulated and within short duct systems.

Question 17

Other Secretory contributors to the whole Saliva

The ___ ____ glands are ____ found in the mouth.

More specifically, they are ___ salivary glands which reside within the surrounding the circumvallate papilla in the ____ __-___ of the tongue, anterior to the ___ ___

These glands are located around _____ and ___ ____in the tongue. These glands empty their serous secretion into the ___ of the moats located around the foliate and circumvallate papillae.

Answer 17

The Von Ebner’s glands are exocrine found in the mouth. More specifically, they are serous salivary glands which reside within the moats surrounding the circumvallate papilla in the posterior one-third of the tongue, anterior to the terminal sulcus.

These glands are located around circumvallate and foliate papilla in the tongue. These glands empty their serous secretion into the base of the moats located around the foliate and circumvallate papillae.

Question 18

Generally Speaking

During the day, ___to ____ ml of saliva is produced, however only about __ml is produced during the night. It is this nocturnal reduction in flow that makes ____________________ important component of caries management.

Answer 18

During the day, 640 to 1200 ml of saliva is produced, however only about 10 ml is produced during the night. It is this nocturnal reduction in flow that makes brushing your teeth before bed an important component of caries management.

Question 19

stimulated Whole Saliva

Stimulated secretion is as the name suggests; it is stimulated. The process is extremely complex involving numerous neurological pathways. One mode of stimulation can be _____.

The term, “Stimulated Saliva” is given to those secretions produced by _____ ____ ____.

It is thought that these secretions aid specifically in ____ and ___ as well as ___, ___, and ________ and ___________.

Answer 19

Stimulated secretion is as the name suggests; it is stimulated. The process is extremely complex involving numerous neurological pathways. One mode of stimulation can be gustatory.

The term, “Stimulated Saliva” is given to those secretions produced by thinking of certain foods, tasting and chewing. It is thought that these secretions aid specifically in digestion and taste as well as protect, buffer, and confer immune response and maintain tooth integrity.

Question 20

SPECIMEN COLLECTION

Answer 20

Five Minute Collection

Question 21

Unstimulated Whole Saliva

FCN

Answer 21

Unstimulated secretion is defined as a resting saliva. It is the saliva that is produced while sleeping, reading, bathing, etc. It is very protective of the dentition and its supporting structures

Question 22

Unstimulated Saliva or Resting Saliva

Always _____

____ ___ flow thru out day

Peak

Lowest

Answer 22

This type of saliva is always present in the mouth and plays a role in protection, buffering, antimicrobial action, and tooth integrity.

lUnstimulated saliva (Resting saliva)

Constant slow flow throughout day, peaking during afternoon and lowest

at 4:00 AM

0.3-0.5 ml per minute secretion rate

Question 23

~ WHOLE SALIVA ~
Left Specimen is a Resting Saliva Specimen.
Right Specimen is Paraffin Stimulated Saliva.

Answer 23

~ WHOLE SALIVA ~
Left Specimen is a Resting Saliva Specimen.
Right Specimen is Paraffin Stimulated Saliva.

Question 24

~ Sialometer ~

Answer 24

Used to Collect Whole Saliva

Question 25

~ SALIVARY FLOW RATES ~ * Approximately\_\_\_\_ Liters of saliva is secreted per day. * The parotid contributes \_\_\_% of the unstimulated saliva while \_\_\_% comes from the submandibular salivary glands and \_\_\_% from the sublingual. * However, during stimulation the parotid can contribute as much as \_\_%.

Answer 25

* Approximately 1.5 liters of saliva is secreted per day. * The parotid contributes 25% of the unstimulated saliva while 60% comes from the submandibular salivary glands and 7-8% from the sublingual. * However, during stimulation the parotid can contribute as much as 50%.

Question 26

~ GLANDULAR FLOW RATES ~ • Parotid Salivary flow rates for unstimulated or restng flow are _____ ml/min and ____ for stimulated flow. • Submandibular and Sublingual gland salivary flow rates are in the range of ____ ml/min when unstimulated and ____ ml/min when stimulated, although both flow rates have wide normal ranges. •

Answer 26

• Parotid Salivary flow rates for unstimulated or restng flow are 0.3-0.5 ml/min and 0.5 – 3.0 for stimulated flow. • Submandibular and Sublingual gland salivary flow rates are in the range of 0.5 – 0.7 ml/min when unstimulated and 0.5-2.0 ml/min when stimulated, although both flow rates have wide normal ranges. •

Question 28

Stimulated Saliva ## Footnote One of the reasons saliva analysis is difficult is because the composition of mixed or stimulated saliva is not the \_\_\_\_\_\_\_\_\_\_\_\_\_, as many proteins are rapidly _____ as they adhere to _____ of teeth and _____ surfaces. ~ For Example ~ The parotid contributes \_\_% of the unstimulated saliva while \_\_% comes from the submandibular salivary glands and \_\_\_% from the sublingual. However, during stimulation the parotid can contribute as much as \_\_\_%.

Answer 28

One of the reasons saliva analysis is difficult is because the composition of mixed or stimulated saliva is not the additive sum of all salivary secretions, as many proteins are rapidly removed as they adhere to hydroxyapatite of teeth and mucousal surfaces. ~ For Example ~ The parotid contributes 25% of the unstimulated saliva while 60% comes from the submandibular salivary glands and 7-8% from the sublingual. However, during stimulation the parotid can contribute as much as 50%.

Question 29

~ SALIVA APPEARANCE ~

Answer 29

Appearance should be slightly turbid (hazy)

Question 30

IN DISEASE

Answer 30

Saliva From a Patient with Systemic Lupus Erythematosus Foamy Saliva From a Patient Sjögren’s Syndrome

Question 31

Gingival Crevicular Fluid ~ ## Footnote Gingival Crevicular Fluid (GCF), is a ___ \_\_\_, and is not a ___ \_\_\_; however, it \_\_\_\_\_\_\_ Gingival crevicular fluid is a fluid occurring in ____ amounts in the ___ \_\_\_\_, believed by some authorities to be an\_\_\_\_ exudate and by others to ____ material from the crevice, containing sticky ___ \_\_\_\_which improve _____ of the epithelial attachment, have ___ \_\_\_\_, and exert\_\_\_ \_\_\_ GCF made of \_\_\_\_\_\_\_\_, \_\_\_\_\_, \_\_\_\_\_\_\_and \_\_\_\_.

Answer 31

Gingival Crevicular Fluid (GCF), is a serum exudate, and is not a glandular secretion; however, it also contributes to the total composition of whole saliva. Gingival crevicular fluid is a fluid occurring in minute amounts in the gingival crevice, believed by some authorities to be an inflammatory exudate and by others to cleanse material from the crevice, containing sticky plasma proteins which improve adhesions of the epithelial attachment, have antimicrobial properties, and exert antibody activity. GCF white blood cells, enzymes, electrolytes and immunoglobulins.

Question 32

~ Gingival Crevicular Fluid ~ \_\_\_\_\_ effects ____ of cells and potentially dangerous bacterial molecules; \_\_\_l action of \_\_\_\_\_; (plaque formation induced by __________ on the gingival margin)

Answer 32

Protective effects clearance of cells and potentially dangerous bacterial molecules; antibacterial action of immunoglobulins; (plaque formation induced by calcium ions on the gingival margin)

Question 33

Tooth Pellicle ## Footnote Tooth pellicle is a ____ \_\_\_\_ of the oral ecology. Salivary & GCF ____ bind to the\_\_\_\_ \_\_\_\_a and the \_\_\_\_. They can also bind to oral \_\_\_\_. Upon secretion they almost immediately ____ to these surfaces via ___ and ______ forces. Bacterial colonization of the tooth pellicle occurs rapidly, usually within a few \_\_\_\_. Gram ____ \_\_\_\_\_ species such as Stretococcus, Actinomyces & Lactobacillus are the \_\_\_\_to colonize the pellicle through the binding of their ____ and ____ to the pellicle.

Answer 33

Tooth pellicle is a biological consequence of the oral ecology. Salivary & GCF glycoproteins bind to the oral mucosa and the dentition. They can also bind to oral prostheses. Upon secretion they almost immediately adhere to these surfaces via electrostatic and van der Waals forces. Bacterial colonization of the tooth pellicle occurs rapidly, usually within a few hours. Gram positive facultative species such as Stretococcus, Actinomyces & Lactobacillus are the first to colonize the pellicle through the binding of their adhesins and fimbriae to the pellicle.

Question 34

Tooth Pellicle

Answer 34

\_\_\_\_ occurs when coaggregation occurs among ____ \_\_\_\_ that do not ____ colonize the tooth and gingival surfaces. It is important to remember that tooth pellicle formation is an oral biological necessity as it prevents \_\_\_\_\_\_\_\_\_\_\_\_\_

Question 35

Brief Summary ## Footnote Salivary glands are classified by __ \_\_\_\_ \_\_\_\_ The major glands are ___ and ___ post-secretion saliva via ____ pathways in the ducts. Minor glands are found on the _________________ surfaces just below and within the mucous membranes, unencapsulated and within short duct systems. The Von Ebner Glands are located at the base of the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Gingival Crevicular Fluid is located in the ___ \_\_\_\_t located between the ____ and the and the ___ \_\_\_ and is not an exocrine secretion. Tooth pellicle is composed of ____ which prevent \_\_\_\_\_\_\_\_\_\_\_\_

Answer 35

Salivary glands are classified by size, location, and histology. The major glands are paired and alter post-secretion saliva via reabsorption pathways in the ducts. Minor glands are found on the labial, lingual, palatal, buccal, glossopalatine, and retromolar surfaces just below and within the mucous membranes, unencapsulated and within short duct systems. The Von Ebner Glands are located at the base of the circumvallate papilla. Gingival Crevicular Fluid is located in the gingival pocket located between the tooth and the and the free gingiva and is not an exocrine secretion. Tooth pellicle is composed of glycoproteins which prevent desiccation of the oral mucosa .

Question 36

The Composition of Saliva ## Footnote Whole saliva is composed of 99.5% water, \_\_\_\_\_\_, \_\_\_\_, \_\_\_\_, and ____ (108 -109 bacteria per mL of saliva). There are also \_\_\_\_\_\_\_, \_\_\_\_, \_\_\_\_\_\_, \_\_\_\_, _____ and, ___ and \_\_\_\_, ___ and \_\_\_.

Answer 36

Whole saliva is composed of 99.5% water, inorganic electrolytes, enzymes, proteins, and bacteria (108 -109 bacteria per mL of saliva). There are also exfoliated mucosal cells, cellular debris, food debris, metabolites, bacterial products and, viruses and viral particulates, fungi and lipids.

Question 37

~ The Biological Necessity of Saliva ~ ## Footnote Speaker Notes: Saliva is not “water” but rather a complex mixture of proteins, enzymes, electrolytes and small organic molecules as shown in this table. At least 40 proteins have been identified in salivary secretions.3 Most of these help to maintain the integrity of the teeth against a constant barrage of physical, chemical and microbial trauma. 3 Not only proteins and lipids, but also the salivary electrolytes and organic molecules such as urea and glucose, are important components of the oral defense system. How these components interact with each other is important in maintaining a balanced and healthy oral environment. Many proteins in saliva we don’t know what they are for

Answer 37

Speaker Notes: Saliva is not “water” but rather a complex mixture of proteins, enzymes, electrolytes and small organic molecules as shown in this table. At least 40 proteins have been identified in salivary secretions.3 Most of these help to maintain the integrity of the teeth against a constant barrage of physical, chemical and microbial trauma. 3 Not only proteins and lipids, but also the salivary electrolytes and organic molecules such as urea and glucose, are important components of the oral defense system. How these components interact with each other is important in maintaining a balanced and healthy oral environment. Many proteins in saliva we don’t know what they are for

Question 38

The Composition of Saliva Interesting concept is the perception that saliva helps ____ \_\_\_\_ (some people think having a dog lick a wound will help it heal faster). Experimental studies in mice have shown wound contraction is significantly faster in the presence of saliva. This may be due to the presence of ____ \_\_\_\_ \_\_\_\_, which is produced by the ____ \_\_\_\_

Answer 38

Saliva is mostly water and the functional components make up only a fraction of the volume. The protein-rich secretions of the salivary glands contain a milieu of antibacterial enzymes, immunoglobulins, lubricants, inorganic elements, and usually contains incredibly high numbers of bacteria. Ironically, it is also the tooth’s first defense against cariogenic pathogens. Interesting concept is the perception that saliva helps heal wounds (some people think having a dog lick a wound will help it heal faster). Experimental studies in mice have shown wound contraction is significantly faster in the presence of saliva. This may be due to the presence of epidermal growth factor, which is produced by the submandibular gland. Oral Histology, A.R. Ten Cate 5th edition, Chapter 15.

Question 39

Factors Affecting The Composition of Saliva

Answer 39

Hydration Smoking Lighting Circadian Rhythm Circannual Rhythm Medications Aging Type of Stimulation Exercise Alcohol Nutrition Systemic Diseases Fasting Fear

Question 40

The Composition of Saliva ## Footnote –Salivary _____ •Control\_\_\_\_\_\_\_\_ •Regulates \_\_\_\_\_ –Salivary \_\_\_\_\_ •Provide\_\_\_\_ for pathogens –Secretory \_\_\_ •Prevents ____ \_\_\_\_to soft tissues

Answer 40

–Salivary proteins •Control [Ca2+ & PO4] •Regulates pH change –Salivary mucins •Provide attachment for pathogens –Secretory IgA •Prevents bacterial adherence to soft tissues

Question 41

Do We Benefit From The Oral Flora? The normal flora \_\_\_\_\_\_\_\_\_. Also, the oral flora contribute to\_\_\_\_\_\_\_\_\_\_\_\_ through the \_\_\_\_\_\_, and they contribute to ________ by inducing \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Finally, the oral bacteria exert ____________ against nonindigenous species by production of inhibitory substances such as _____ \_\_\_\_\_ \_\_\_\_\_

Answer 41

The normal flora occupy available colonization sites which makes it more difficult for other microorganisms (nonindigenous species) to become established. Also, the oral flora contribute to host nutrition through the synthesis of vitamins, and they contribute to immunity by inducing low levels of circulating and secretory antibodies that may cross react with pathogens. Finally, the oral bacteria exert microbial antagonism against nonindigenous species by production of inhibitory substances such as fatty acids, peroxides and bacteriocins.

Question 42

The Entero-Salivary Circulation of Nitric Oxide Metabolites ## Footnote Nitrate, after its absorption in the upper ______ \_\_\_\_\_\_ reaches the salivary glands via the ____ \_\_\_\_ where it is secreted into the ___ \_\_\_and\_\_\_\_ ____ to _____ by the\_\_\_\_\_\_. There is a linear relationship between the amounts of nitrate ____ and amounts of nitrate and nitrite \_\_\_\_\_\_ Systemically absorbed nitrate is concentrated 10-fold in the salivary glands and undergoes an entero-salivary circulation where it is reduced to nitrite by bacterial ____ \_\_\_\_\_ on the ___ surface of teh \_\_\_\_ and\_\_\_\_ into the ____ providing a source of ____ \_\_\_\_\_ nitrite/NO. Nitrite is transported in the ___ \_\_\_\_ to _____ vessels, where ___ \_\_\_\_ tension favors the reduction of ____ \_\_\_causing vaso\_\_\_\_\_\_, with consequent ___ of BP.

Answer 42

Nitrate, after its absorption in the upper gastrointestinal tract, reaches the salivary glands via the blood circulation where it is secreted into the oral cavity and partially reduced to nitrite by the oral microflora. There is a linear relationship between the amounts of nitrate ingested and amounts of nitrate and nitrite found in saliva. Systemically absorbed nitrate is concentrated 10-fold in the salivary glands and undergoes an entero-salivary circulation where it is reduced to nitrite by bacterial nitrate reductases on the dorsal surface of the tongue, and swallowed into the stomach providing a source of systemically available nitrite/NO. Nitrite is transported in the arterial circulation to resistance vessels, where lower O2 tension favors the reduction of nitrite to NO, causing vasodilatation, with consequent lowering of BP.