Saliva part 1 Lecture

How much of saliva is water?

99.5%

What is the general composition of saliva?

Protein and enzymes (40 essential proteins)

Small Organic Molecules (n=7)

Electrolytes (13 Electrolytes and Minerals)

How does saliva counteract an acidic mouth?

Acidic mouth causes erosion of teeth, so minerals in saliva help replenish lost minerals from acid.

Factors Affecting the Composition of Saliva

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

What are the functions of saliva?

Protective, Food-Related, Communication

What are the protective functions of saliva?

Lubrication

Antibacterial, Antifungal, Antiviral

Mucosal Integrity

Lavage, cleansing

Buffering Capacity

Remineralization

What is mucin?

Anti-microbial protein that cause bacteria to aggregate

What heals faster: a cut on your hand or a cut in your mouth?

A cut in your mouth heals faster due to the anti-microbial proteins in saliva.

What are the food-related functions of saliva?

Preparation for digestion

Digestion

Mucosal integrity

Taste

What are the communication functions of saliva?

Speech. You can't speak with a dry mouth.

Biological necessity of saliva

Multi-dimensional functions. Includes protection of the soft and hard oral tissues. Essential in the processes of alimentation and communication.

Intraoral functions of saliva

Lubricating and moistening of food for swallowing

Temperature regulation of solid foods and liquids

Solubilizing material so it can be tasted

Preventing dental caries

Speaking

Cleansing of mouth

Systemic functions of saliva

Initiating digestion

Maintaining pH of upper GI

Maintaining the health of oral mucosa

Preventing opportunistic infections by keeping microflora balance

Cleansing of clearing the esophagus

How many salivary glands are there?

Hundreds. 3 pairs of major glands and many minor glands.

What type of cells produce saliva?

Glandular epithelium

What are Glandular epithelial cells?

Specialized epithelial cells that produce and release products in the body, such as saliva, mucous, digestive juices, and other fluids

How are glands classified?

According to the mechanism of secretion

What are the two types of glands

Endocrine and exocrine

Exocrine glands

secrete their products via ducts onto the apical surface

Endocrine glands

Release hormones into your bloodstream

Polyductal/Compound duct System

Highly branched duct system

MAJOR SALIVARY GLANDS

Monoductal/Simple duct systems

Unbranched duct

MINOR SALIVARY GLANDS

What are the major salivary glands and their secretions?

Parotid gland - serous secretion

Submandibular gland - mixed serous and mucous secretion

Sublingual gland - Mostly mucous secretion

What are the characteristics of a Serous acinus cell?

- Spherical nucleus

- Taller

- Secretory granules rich in protein

- Secretes proteins in an isotonic watery fluid

- Contains enzymes, antibodies, electrolytes, and other substances

- Aids in the initial digestion of food

What are the characteristics of a mucous acinus cell?

- Shorter

- Secretory products filled with mucous and causes a squished nucleus

- Composed of mainly glycoproteins called mucins

- Serves as a protective barrier, lubricant, and moisturizer

- Helps to trap foreign particles, pathogens, and debris

What is Stage 1 of the Two-stage Salivary Gland Secretion Model?

Acinar cells secrete a NaCl rich fluid called PRIMARY SALIVA which is ISOTONIC

What is Stage 2 of the Two-stage Salivary Gland Secretion Model?

Primary saliva is subsequently modified through its passage along the ductal tree mostly by reabsorbing NaCl and secreting KHCO3.

Because the ductal epithelium is poorly permeable to H2O, the final saliva is HYPOTONIC.

Parotid Gland

entirely SEROUS

largest

Where is the Parotid gland located?

Close to ear canals, extends to lower mandible. Outside of mouth.

What is the duct of the Parotid gland, and where is it located?

Stenson's duct communicates with the oral cavity and is located opposite of the maxillary second molar.

What is the size, shape, and weight of the Parotid gland?

6 x 4 cm

Inverted pyramid

Approximately 15 to 30g

What are the arteries of the Parotid gland?

External carotid

Posterior auricular

Superficial temporal

Transverse facial

Maxillary arteries

What is the vein of the Parotid gland?

Retromandibular vein

What are the lymph nodes of the Parotid gland?

Deep parotid lymph nodes

Superficial cervical lymph nodes

Deep cervical lymph nodes

What is the function of Myoepithelial cells?

Constrict intercalated duct and squirt saliva into duct.

What is the function of Acinar epithelium cells?

Secretes proteins and isotonic filtrate

Submandibular Gland

Mixed secretion, but predominately serous

What is the shape, weight, and size of the submandibular gland?

egg-shaped

7 - 19 g

4 x 5 cm

What is the location of the submandibular gland?

Looks like a "J". Bilaterally, in the submandibular fossa on the medial surface of the body of the mandible below the mylohyoid line.

What is the submandibular duct and where is it located?

Wharton's duct. Exits from the deep part of the gland and ascends anteriorly to the floor of the mouth. On the frenulum of the tongue.

What are the arteries and veins for the submandibular gland?

Facial and lingual arteries

Submental and facial veins

What are the lymph nodes of the Submandibular gland?

Submandibular lymph nodes

Sublingual Gland

Smallest. Mixed secretion but predominantly mucous

What is the shape, weight, and dimensions of the sublingual gland?

Almond shape

2-3 g

3-4 cm

What are the ducts of the Sublingual gland

Duct of Rivinus (~15 ducts that drain the sublingual gland)

Duct of Bartholin (Largest sublingual gland excretory duct and joins Wharton's duct near the sublingual caruncle)

Where is the sublingual gland located?

Under the mucous membrane of the floor of the mouth between the mandible and the genioglossus muscle

What are the arteries of the Sublingual gland?

Submental and Sublingual arteries

What are the lymph nodes for the sublingual gland?

Submental and Submandibular lymph nodes

Where are minor salivary glands located?

tongue, palate, buccal, and labial mucosa

Properties of the minor salivary glands

600-1000 minor salivary glands

1-5 mm

Single duct

Serous, Mucous, or mixed

What are the 3 minor salivary glands we should know?

Weber's glands

Von Ebner's glands

Blandin-Nuhn's glands

Von Ebner's Glands

Only SEROUS minor gland

Helps cleaning between papilla when food or debris gets stuck

both sides of oral cavity toward the back of your tongue

Glands of Blandin-Nuhn

anterior portion of the ventral portion of the tongue

mixed secretion

Weber's Glands

Lateral posterior portion and on both sides of the tongue.

MUCOUS

Gingival Cervical Fluid

-serum exudate NOT glandular secretion

-contributes to total composition of whole saliva

-inflammatory exudate derived from periodontal tissue and to cleanse material from the crevice

What components make up GCF?

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

Parasympathetic System and Saliva

-Begins with Glosspharyngeal nerve (CN9)

-Synapsis at the Otic ganglion

-The Auriculotemporal nerve carries parasympathetic fibers from Ottic ganglion to the Parotid Gland

-The Auriculotemporal is a branch of V3 of the mandibular nerve

-Parasympathetic stimulation causes and INCREASE OF SALIVA PRODUCTION

Sympathetic System and Saliva

-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

-Increase activity of the SYMPATHETIC NS INHIBITS THE SALIVARY PRODUCTION via vasoconstriction.

Parasympathetic vs. Sympathetic

Parasympathetic: Stimulation produces watery saliva

Sympathetic: Stimulation produces viscous saliva due to secretion of proteins like mucin, IgA, etc. Making saliva thick and ropey.

Sensory Innervation (Not in lecture, but maybe still know it)

-The Sensory Innervation is supply for Auriculotemporal nerve for the gland itself

-The great auricular nerve (GA) for the fascia