Saliva ?

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Questions and Answers

What is the source of the parasympathetic supply to the submandibular and sublingual glands?

Internal carotid artery

Middle meningeal artery

Facial (7th) nerve via the chorda tympani branch (correct)

Sphenopalatine ganglion

Which nerve carries the sympathetic fibers to the parotid gland?

Glossopharyngeal nerve

Auriculotemporal nerve (correct)

Facial nerve

Greater petrosal nerve

What is the function of the parasympathetic stimulation regarding salivary flow when relaxed?

Increases salivary flow through vasodilation (correct)

Decreases salivary flow

Inhibits the secretion of saliva

Increases salivary flow through vasoconstriction

Which of the following is NOT a pathway for parasympathetic supply to the nasal and palatine regions?

Lingual nerve Signup and view all the answers

Which structure does the parasympathetic supply to the parotid gland synapse at?

Otic ganglion Signup and view all the answers

The sympathetic innervation to glands in the hard and soft palate originates from which artery?

Internal carotid artery Signup and view all the answers

The post-ganglionic fibers to the submandibular and sublingual glands travel with which nerve?

Lingual nerve Signup and view all the answers

What is the role of the sphenopalatine ganglion in the autonomic supply to the palate?

It is exclusively involved in parasympathetic supply Signup and view all the answers

How do ions in saliva contribute to the health of newly erupted teeth?

They aid in the maturation of immature enamel. Signup and view all the answers

What role does the salivary pellicle play in the oral cavity?

It protects against acid but also promotes plaque formation. Signup and view all the answers

What happens to saliva quantity when changing from day to night?

It decreases to about 10ml at night. Signup and view all the answers

How does saliva act as a buffer in the oral cavity?

Through the presence of calcium phosphate and inorganic ions. Signup and view all the answers

What is the effect of impaired saliva flow on oral health?

It leads to increased plaque deposition and caries. Signup and view all the answers

What can affect the quantity of saliva produced?

Time of day and presence of stimulation. Signup and view all the answers

What is the main protective function of saliva against caries?

It helps to control the effects of demineralisation and remineralisation. Signup and view all the answers

What condition can severely impair saliva function?

Use of certain medications. Signup and view all the answers

What effect does serous saliva have on oral health?

It reduces the amount of fermentable carbohydrates available. Signup and view all the answers

Which factor is NOT associated with changes in saliva production?

Hair color of the individual. Signup and view all the answers

What is the average daily production of saliva in liters?

1-1.5 liters Signup and view all the answers

Which salivary gland produces the largest percentage of total saliva?

Submandibular gland Signup and view all the answers

Which of the following components is most likely found in whole saliva but not in pure saliva?

Bacteria Signup and view all the answers

What are the two consistencies in which saliva can be produced?

Serous and mucous Signup and view all the answers

What is a significant factor that can impact salivary flow?

Hydration levels Signup and view all the answers

What is the function of crevicular fluid in saliva during periodontal disease?

Indicates inflammation Signup and view all the answers

What percentage of saliva produced comes from the parotid gland?

25% Signup and view all the answers

What is the primary role of saliva in the mouth?

Buffering acids Signup and view all the answers

In terms of oral health, what is a potential consequence of xerostomia?

Increased risk of gum disease Signup and view all the answers

How does the composition of whole saliva differ from pure saliva?

Whole saliva includes oral debris Signup and view all the answers

What is the primary pathway for taste sensation from the anterior two-thirds of the tongue to the brain?

Lingual nerve to the submandibular ganglion then to the facial nerve Signup and view all the answers

Which condition is most likely to cause xerostomia?

Radiation therapy Signup and view all the answers

Which of the following is NOT a factor that can increase saliva production?

Diabetes Signup and view all the answers

Hypersalivation can be a result of which of the following medical conditions?

Cerebral palsy Signup and view all the answers

What type of salivary flow condition is often associated with medications?

Xerostomia Signup and view all the answers

What occurs when the pH of plaque fluid falls below 5.5?

Mineral ions leave enamel Signup and view all the answers

What is the main role of saliva in relation to calcium and phosphate ions?

To serve as a reservoir for calcium and phosphate Signup and view all the answers

Which nerves control the salivation process?

Sympathetic and parasympathetic nerves Signup and view all the answers

What happens to the solubility limit of plaque fluid as pH falls below 6.0?

It increases, allowing more ions to dissolve Signup and view all the answers

How does sympathetic stimulation affect salivary flow?

It promotes a dry mouth due to vasoconstriction Signup and view all the answers

What is caused by the repeated fluctuations in plaque pH?

A seesaw effect of ions across the enamel/plaque interface Signup and view all the answers

What is the immediate effect of a decrease in pH at the enamel/plaque interface?

Migration of ions from enamel and plaque Signup and view all the answers

What typically stimulates salivation?

Visual and olfactory cues, as well as taste Signup and view all the answers

What might happen when the buffering action of saliva is effective?

Mineral ions may return to the enamel Signup and view all the answers

What is the role of calcium and phosphate ions in enamel?

To provide structural integrity to the enamel Signup and view all the answers

Study Notes

Parasympathetic Stimulation

Increases salivary flow, this is due to vasodilation.
Stimulates secretomotor supply to the salivary glands, resulting in salivation.

Hard & Soft Palate Glands: Sympathetic Supply

Originates from the internal carotid artery.
Travels to the sphenopalatine ganglion.
Branches then run with the greater palatine, lesser palatine and pharyngeal nerves of the trigeminal nerve (maxillary division).

Hard & Soft Palate Glands: Parasympathetic Supply

Originates from the superior salivary nucleus of the brain.
Travels with the facial (7th) nerve.
Travels via the greater petrosal nerve.
Then travels via the nerve of the pterygoid canal to the sphenopalatine ganglion where there is a synapse.
Post-synaptic fibers run from the ganglion with branches of the maxillary division of the trigeminal nerve (greater palatine, lesser palatine and pharyngeal nerves) to the hard palate, soft palate and pharyngeal glands.

Submandibular and Sublingual Glands: Sympathetic Supply

From the facial artery
Via the submandibular ganglion and the lingual nerve (branch on the mandibular division) to the submandibular and sublingual glands.

Submandibular & Sublingual Glands: Parasympathetic Supply

From the superior salivary nucleus of the brain via the facial (7th) nerve.
Travels via the chorda tympani branch.
Travels to the submandibular ganglion where there is a synapse.
Post-ganglionic fibers run with the lingual nerve, a branch of the mandibular division of the trigeminal nerve to the submandibular and sublingual glands.

Parotid Glands: Sympathetic Supply

From the middle meningeal artery
Travels via the otic ganglion and the auriculotemporal nerve (a branch of the mandibular division) to the parotid.

Parotid Glands: Parasympathetic Supply

From the inferior salivary nucleus of the brain via the glossopharyngeal (9th) nerve.
Travels via the tympanic plexus of the middle ear and the lesser petrosal nerve to the otic ganglion, where there is a synapse.

Saliva & Caries: Protective Function

Saliva has a protective function.
Patients with impaired salivary flow can have fast plaque deposition, rampant caries, and severe periodontal disease.

Salivary Function During Caries Formation

The salivary pellicle, made up of glycoproteins, protects against acid, but also encourages adherence of plaque bacteria.
Supersaturation of inorganic ions helps to maintain a neutral pH and act as a buffer to control acid in solution.
This aids in the control of demineralization and remineralization processes.

Serous Saliva

Serous saliva's cleansing effect can reduce the amount of fermentable carbohydrate available for conversion to acid.

Saliva Quantity

Varies:
- Day vs. night (1-1.5 liters during the day, 10ml at night).
- On stimulation (eating or not).
- Affected by drugs, illness, and radiation.

The Ionic See-Saw

Saliva contains calcium phosphate which naturally inhibits demineralization and promotes remineralization.
It can readily do this during short drops in pH, but cannot keep up during prolonged periods of acid attack.
The salivary buffering system can reduce the extent of the fall in pH when sugars enter the mouth, but prolonged exposure can exhaust the system's ability to contain ion removal.

Saliva's Role in Demineralization & Remineralization

When the pH falls below 6.0, the plaque fluid's solubility limit increases, reducing the concentration of calcium and phosphate ions.
If the buffering action is effective and the pH rises, the additional mineral ions in the plaque fluid will exceed its capacity to hold them, causing the mineral ions to return to the enamel.
The repeated fluctuation in plaque pH produces a seesaw of ions across the interface between the enamel and the plaque fluid.

Mechanism of Salivation

Salivation is a reflex mechanism stimulated by sensory inputs: sight, smell, and taste.
It is also controlled by the sympathetic and parasympathetic nerves:
- Sympathetic stimulation reduces salivary flow (e.g., in stressful situations, your mouth goes dry), which is due to vasoconstriction.
- Parasympathetic stimulation increases salivary flow (e.g., when you are relaxed, your mouth waters at the sight, smell, or taste of something appealing), due to vasodilation.

Salivary Flow Factors

Increase salivary flow:
- Mastication
- Irritants
- Gingival conditions
- Hunger
- Smell/sight of food
- Teething in babies
Decrease salivary flow:
- Drugs
- Diabetes
- Alcohol
- Fear
- Radiotherapy
- Surgery

Medical Conditions Impacting Saliva Production

Hypersalivation: The excess production of saliva. Occurs with conditions like Parkinson's, motor neurone disease, or cerebral palsy.
Xerostomia: Dry mouth due to a reduction or absence of saliva. Occurs with conditions like Sjogren's syndrome, diabetes, HIV/AIDS, radiation/chemotherapy, or salivary gland disorders.

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Description

Test your knowledge on the autonomic nervous system with a focus on parasympathetic and sympathetic stimulation, particularly in relation to salivary glands and glandular supply to the palate. This quiz covers the pathways and functions of the nervous system that affect salivation and glandular secretions.