2. Salivation & Swallowing

Question 0

How much saliva do we produce on an average day?

Answer 0

1.5 L

Question 1

What cranial nerve controls the muscles of mastication?

Answer 1

Trigeminal

Question 2

List the functions of saliva

Answer 2

Starts digestion of carbs (salivary Amylase)

Protects oral environment by keeping it moist & relatively alkaline

Aids swallowing by helping to form a food bolus

Question 3

What might occur if there is poos saliva production?

Answer 3

Poor dental hygiene: caries, infections

Harder to chew & swallow

Harder to speak

Question 4

What are the main components of saliva?

Answer 4

Water
Electrolytes
HCO3- (bicarbonate)
Mucus
Enzymes

Question 5

How does saliva become hypotonic, compared with plasma ?

Answer 5

Ductal cells modify the composition of saliva

Na+ removed from saliva in exchange for K+ & HCO3-

Overall effect: saliva becomes hypotonic relative to plasma

Composition of saliva varies depending on vol of saliva produced:
low = more hypotonic, neutral/slightly acidic, contains fewer enzymes

Question 6

When are the following higher: when resting or stimulated?
Volume
Hypotonicity
Alkalinity
Enzyme content

Answer 6

Volume higher when stimulated
Hypotonicity higher when resting
Alkalinity higher when stimulated
Enzyme content higher when stimulated

Question 7

Situations when saliva production may be decreased

Answer 7

Dehydration

Certain medications (muscarinic antagonists)

Disease (e.g. Sjogrens)

Question 8

3 areas where a tumour may be located for symptoms of difficulty swallowing solid foods, but little difficulty swallowing fluids

What category of cancer may be present in each area

Answer 8

Oropharynx (squamous cell carcinoma)

Oesophagus (squamous cell carcinoma)

Cardia of stomach (adenocarcinoma)

Question 9

Symptoms of malignancy of oesophagus/cardia of stomach

Answer 9

Weight loss
Pain
Malaena
Harmatemesis

Question 10

Potential causes of difficulty swallowing solids but not fluids

Answer 10

Malignancy

Strictures within oesophagus (from fibrous rings or peptic erosions)

Question 11

Broadly define:
Oesophageal dysphagia
Oropharyngeal dysphagia

What investigations may be useful for each?

Answer 11

Oesophageal dysphagia:
Difficulty swallowing solids
Upper GI endoscopy/Barium swallow

Oropharyngeal dysphagia:
Difficulty swallowing fluids
VFSS: allows phases of swallowing to be evaluated

Question 12

Possible causes of Odynophagia

Answer 12

Oesophageal candidiasis
Oesophagitis
Peptic ulcerations
Cancers within oropharynx or oesophagus