Saliva I

Whole saliva

99.5% water + functional components (proteins and enzymes, small organic molecules, electrolytes)

factors affecting the composition of saliva

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

functions of saliva

protective, food-related, communication

protective function of saliva

lubrication

antibacterial, antifungal, antiviral

mucosal integrity

lavage, cleansing

buffering capacity

remineralization

lubrication - salivary components involved

Water, mucins, proline-rich glycoproteins coatsurfaces of oral mucosa, throat, and food

antibacterial, antifungal, antiviral - salivary components involved

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

Mucosal integrity - salivary components involved

Mucins, electrolytes, water

Lavage, cleansing - salivary components involved

water

Buffering Capacity - salivary components involved

Bicarbonate and phosphate, proteins

Remineralization - salivary components involved

Calcium, phosphate, proline-rich glycoproteins

anti-microbial proteins in saliva

statherin, mucin, lysozyme, lactoferrin, salivary peroxidase, lactoperoxidase, histatins, cystatins

Statherin

a small protein that inhibits calcium phosphate precipitation, preventing dissolution of hydroxyapatite

Mucin

causes bacteria to aggregate

Lysozyme

disrupts the bacterial cell wall, leading to bacterial lysis

Lactoferrin

has iron-binding properties that help inhibit bacterial growth, reduce biofilm formation, and protect against various pathogens.

Salivary peroxidase

reacts with salivary thiocyanate when H2O2 is around and forms hypothiocyanite, which inhibits bacterial glucose metabolism

Lactoperoxidase

adsorbs to hydroxyapatite, altering primary bacterial attachment

Histatins

Antimicrobial wound closers

Cystatins

Affect mineral balance of the tooth

Food-related function of saliva

preparation for digestion

digestion

mucosal integrity

taste

preparation for digestion - salivary components involved

water, mucins, proline-rich glycoproteins

digestion - salivary components involved

amylase, ribonuclease, lipase

mucosal integrity - salivary components involved

mucins, electrolytes, water

taste - salivary components involved

water, gustin (zinc,binding salivary protein)

communication function of saliva

speech

lubrications from ______ and ________ assists in the ability to speak

water; mucins

biological necessity of saliva

-protection of soft and hard oral tissues

-essential in processes of alimentation and communication

Saliva intraoral functions

•Lubricating and moistening food for swallowing

•Regulating temperature of solid foods and liquids

•Solubilizing material so it can be tasted

•Preventing dental caries

•Assisting in speaking

•Cleansing the mouth

Saliva systemic functions

•Initiating digestion

•Maintaining pH of the upper GI tract

•Maintaining the health of the oral mucosa

•Preventing opportunistic infections by keeping microflora balanced

•Clearing the esophagus

what produces saliva

-glandular epithelium (glandular epithelial cells)

exocrine glands

-different shapes

-Secrete their products via ducts onto the apical (or epithelial) surface.

major salivary glands

parotid, submandibular, sublingual

Parotid gland

-produces a serous, watery secretion

-largest

Stenson's duct

-Secretory duct of Parotid gland

-communicates with the oral cavity

-Duct is located opposite the second molar

Parotid gland blood supply

-provided by glandular branches from several arteries.

-These arteries are external carotid, posterior auricular, superficial temporal, transverse facial and maxillary arteries.

-Blood return is provided by the retromandibular vein.

Parotid gland lymphatics

drain into the deep parotid nodes embedded deep within the gland and to the superficial and deep cervical nodes.

Parotid gland micro-anatomy

-Acinus has acinar cells.

-Myoepithelial cells constrict intercalated duct and squirt saliva into striated duct.

-Acinar epithelium secretes proteins and isotonic filtrate

Sublingual gland

-secretes saliva that is predominantly mucous in character

-smallest

Sublingual gland blood supply

arteries to the gland are branches of the submental and sublingual arteries

Sublingual gland lymphatics

drains into the submental and submandibular

lymph nodes

Ducts of Rivinus

a group of excretory ducts, drain the sublingual gland

Duct of Bartholin

-largest sublingual gland excretory duct

-joins Wharton's duct near the sublingual caruncle

Submandibular gland

-produces a mixed serous & mucous secretion

-predominantly serous

Submandibular gland blood supply

-facial and lingual arteries supply the gland.

-veins of the gland are tributary to the submental and facial veins.

Submandibular gland lymphatics

drainage flows to nearby submandibular nodes

Wharton's duct

-submandibular duct

-exits from the deep part of the gland and ascends anteriorly to the floor of the mouth

Serous acinus

-parotid and submandibular gland

-secretes proteins in an isotonic watery fluid

-Contains enzymes, antibodies, electrolytes, and other substances

-Aids in the initial digestion of food

Mucous acinus

-sublingual and submandibular gland

-Composed mainly of glycoproteins called mucins

-Serves as a protective barrier, lubricant, and moisturizer

-Helps to trap foreign particles, pathogens, and debris

Minor salivary glands

-additional specialized epithelial tissues located on the oral mucosa and the tongue

-produce saliva in the oral cavity

-single duct

-serous, mucous, or mixed

Minor salivary glands location

tongue, palate, buccal, and labial mucosa

Weber's glands

-lateral posterior portion and on both sides of the tongue

-minor salivary gland

Weber's glands secretion

Mainly mucous, producing a thicker, more viscous fluid

Weber's glands function

-Help with swallowing, especially dry foods, by providing lubrication.

-Contribute to taste, particularly for taste buds located at the back of the tongue

Von Ebner's glands

-base of tongue

-minor salivary gland

Von Ebner's glands secretion

Primarily serous, meaning they release a watery fluid rich in enzymes

Von Ebner's glands function

-Secretes lingual lipase, an enzyme that begins breaking down fats.

-Flush the taste buds, allowing for quick perception of new tastes.

-May have a role in taste, especially for taste buds located at the back of the tongue

Blandin-Nuhn's glands

-anterior portion of tongue

-minor salivary gland

Gingival Crevicular Fluid (GCF)

-serum exudate

-not a glandular secretion

-contributes to the total composition of whole saliva

-inflammatory exudate derived from the periodontal tissues

Gingival Crevicular Fluid (GCF) composition

serum and locally generated materials such as tissue breakdown products, inflammatory mediators, and antibodies directed against dental plaque bacteria

Parotid gland nerve supply

sensory and autonomic innervation

Sympathetic

-inhibit saliva production

-Originates from the Superior Cervical Ganglion

-Part of the sympathetic Chain

-Fibers from the ganglion travels along with the external carotid artery to reach the PAROTID GLAND

Parasympathetic

-increase of saliva production

-Begins with the Glossopharyngeal nerve (CN9)

-Synapsis at the Otic ganglion

-The Auriculotemporal nerve carries parasympathetic fibers from the Otic ganglion to the Parotic Gland

-The Auriculotemporal is a branch of V3 the mandibular nerve

Sensory innervation

supply for Auriculotemporal nerve for the gland itself

Great auricular nerve (GA) for the

fascia