Salivary Secretion

Question 1

What are the types of salivary glands?

Answer 1

a) parotid
b) submandibular
c) sublingual

Question 2

What are the types of protein secretions by saliva?

Answer 2

a) serous secretion
- contains ptyalin and digest starch

b) mucus secretion
- contains mucin for lubricating and for surface protection

Question 3

What are the functions of saliva?

Answer 3

a) chemical digestion: breaks down starch by function of salivary amylase
b) lubricating effect: moisturizes the inside of the mouth and creates smoother speech
c) solvent effect: dissolves food and allows the tongue to taste food
d) cleaning effect: washes away food debris and bacteria remaining in the mouth
e) antibacterial effect: lysozyme, peroxidase and lactoferrin fight against pathogenic microorganisms
f) pH buffering effect: prevents sudden changes in pH
g) supplies minerals: calcium, phosphorus to teeth

Question 4

What is xerostomia?

Answer 4

Dryness of mouth due to hyposalivation or absence of salivary secretion (aptyalism)

Question 5

Name some conditions when hypersalivation occurs

Answer 5

a) Decay of tooth or neoplasm of tooth or tongue
b) Diseases of esophagus, stomach and intestine
c) Neurological disorders like cerebral palsy and mental retardation
d) Parkinsonism
e) Psychological and psychiatric conditions
f) Nausea and vomiting

Question 6

Name some conditions when hyposalivation occurs

Answer 6

• Temporary hyposalivation occurs in emotional conditions like fear, fever and dehydration
• Permanent hyposalivation occurs in sialolithiasis, congenital absence of salivary glands and Bell’s palsy

Question 7

What are the nerves supplying the salivary gland?

Answer 7

• supplied by sympathetic and parasympathetic nerves
• Parasympathetic nerve to parotid gland arises from the inferior salivary nucleus and reach the parotid gland by passing through glossopharyngeal nerve
• Parasympathetic nerves to submandibular and sublingual glands arise from the superior salivary nucleus and reach the glands by passing through the facial nerve
• Sympathetic nerves to the salivary glands arise from the lateral horns of first and second thoracic segments in spinal cord and reach the glands by passing through the postganglionic fibers of the superior cervical ganglion

Question 8

What are the effects of stimulation of parasympathetic nerve fibers to the salivary glands?

Answer 8

• causes vasoconstriction

- increases secretion of watery saliva

Question 9

What are the effects of stimulation of sympathetic nerve fibers to the salivary glands?

Answer 9

• causes vasodilation

- increases secretion of proteinaceous saliva

Question 10

What are the properties of saliva?

Answer 10

a) Volume: 800 - 1500 mL/day

b) Reaction and pH: slightly acidic with a pH of 6 - 7