Salivary Glands

Whole Saliva

• Mixed Fluid in the Mouth

• Fluid orginates from:
  Capillaries, Interstitial fluid (in between cells)

• 90% from the Major Salivary Glands

• Once saliva is stimulated

• 10% is from Minor Salivary Glands

Daily Secretions

0.5L - 2L
(range from different references)

Whole Saliva also contains?

• Gingival Crevicular Fluid

• Microorganisms

• Food Debris

• 99% Water, 1% Dry Matter such as Proteins, Salts (NaCl, Ca, Glacium)

Resting State - Whole Saliva

2/3 of Volume is produced by Submandibular Gland

Stimulated State - Whole Saliva

½ of volume is produced by Parotid Gland

Minor Glands

secretes minor amount of saliva to keep the mucous moist

Areas without salivary glands

• Anterior Hard Palate

• Anterior 2/3 of dorsum of the tongue

• Gingiva

Labial Glands

upper and lower lips

Mucocele

painless, harmless fluid-filled cyst that forms in the mouth

• Minor salivary duct is injured or blocked

• Commonly caused by minor trauma (biting your lip accidentally)

• Affects Labial Glands

Nicotine Stomatis

• affecting palatine glands

• from a chronic reverse smoking

Ember is inside when smoking

Orifice of ducts are inflamed, causes redness

Lesions mark the palatal glands

Palatine Glands

• Type of secretion: Mucous

• Location: Soft palate and in the posterior lateral parts of the hard palate

Buccal Glands

• Type of secretion: Seromucous

• Location: Inner cheek region

Anterior Lingual Glands

• Type of secretion: mostly mucous

• Location: near tip of the tongue

Posterior Lingual Glands

• Type of secretion: pure mucous

• Location: pure mucous

Lingual Glands of Von Ebner

• Type of secretion: pure serous

• Washes off taste buds

• Location: beneath the vallate papillae

• Open into the trough around the gland

• Volatile substances reaches the nose which is why you cannot taste well if you have colds

Glossoplatine Glands

• Type of secretion: pure mucous

• Location: (P) lateral parts of the palate down into the (A) fold of tissue in front of the palatine tonsil

Parotid Glands

• side of the face near the ear

• AKA Stensen’s Duct

• Location: Opposite of the Maxillary 2nd Molar

• About 5cm long

• Largest glands

• Roughly wedge shaped

• Pure serous sewcretions

• There are still mucous cells

Parotid Papilla

• Small elevation on the cheeks that marks the opening parotid duct

When stimulated - Parotid Glands

½ of whole saliva volume

When resting - Parotid Gland

25% of the total resting salivary volume

Parotitis 

• inflammation of one or both parotid glands

• AKA Mumps

• Viral, by mumps virus

• Can cause infertility

Submandibular Glands

• AKA Submaxillary gland

• Below and toward the posterior part of the mandible

• AKA Wharton’s duct

• Wrapped around the mylohyoid muscle

• Opens at the sublingual caruncula or caruncle

• Mixed gland

• Mainly mucous

• Viscous

Resting state - Submandibular Glands

2/3 volume of whole saliva (60-65%)

Sharp turns

prone to sialolith

• salivary duct blockage

Sublingual Glands

• smallest major salivary glands

• Location: (A) floor of the mouth

• next to mandibular canines

• AKA Bartholin’s duct

• Has smaller ducts called Rivinian or Ducts of Rivinus

• Runs along with Wharton’s duct and opens at the sublingual caruncle

Functions of Saliva

Protection

• Cleansing (mechanical) mouth

• Clearance of food

• Lubrication of mucosa

• Mineralization of teeth

• Maintenance of pH level

• Neutralization of acids

• Exertion of antimicrobial effects/action

Functions of Saliva

Digestion and Speech

• Formation of food bolus

• Mastication and deglutition

• Initial breakdown of carbohydrates and lipids

• Production of speech

• Taste

Acinar cells

• secretory end-pieces

• comprise 80% of gland mass

• Primary saliva is formed here

• membranes have higher water permeability

• lets water to freely pass the cell membrane

Striated duct cells

• columnar with deep membrane infoldings

• increase mitochondria

• modifies the primary saliva

• membranes have lower water permeability

• strict with water

• releases Kallikerin

• circulating plasma proteins that induce formation of bradykinins

• for the regulation of blood flow to the salivary gland

• Excretory duct - lined by stratified columnar epithelium

Blood supply

Portal system with two capillary network series

• Dense, around duct system

• Around secretory end-pieces

Blood supply

Blood vessels controlled by:

• Sympathetic Nervous System - constriction of vessels

• Parasympathetic Nervous System - dilation of vessels

Masticatory-salivary reflex

• Trigeminal innervation

• Inputs from:

1. Mechanoreceptors via PDL

2. Muscle spindles in masticatory muscles

Gustatory-salivary reflex

• CN VII, CN IX, CN X

• Chemoreceptors in taste buds within:

1. Lingual papillae

2. Tonsilar region

3. Epiglottis

4. Pharyngeal Wall

5. Esophagus

Salivatory Nuclei

control the salivary glands

Neurotransmitters

determine the flow rate and composition

• Acetylchloline (Ach) - post ganglionic parasympathetic

• Noradrenaline (NA) = sympathetic (AKA Norepinephrine)

Flow rate depends on

NID

• Nature of Stimulus

• Intensity of Stimulus

• Duration of Stimulus

Parasympathetic stimulation

• more flowy

• more water = increased flow rate

Sympathetic stimulation

• more viscous

• less water = decreased flow rate

Fear/anxiety

sympathetic

Food

parasympathetic

Sialolith

salivary duct blockage

Ranula

trauma