Oral and Gastric Physiology and Biochemistry Flashcards Preview

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Flashcards in Oral and Gastric Physiology and Biochemistry Deck (20):
1

How much saliva do you produce per day?

1 liter

2

Name the three major salivary glands and their innervation.

Parotid - Glossopharyngeal IX
Submaxillary - Facial VII
Sublingual - Facial VII

3

What is the function of lysozyme in saliva?

kills gram positive bacteria (but not gram negative)
Cleaves beta 1,4-linkages between NAM and NAG (in fungi too!)

4

What are some other components of saliva that act as bacterial defense?

Peroxidase: kills by producing reactive bromide and iodine molecules
Lactoferrin: binds iron and prevents bacteria/fungi growth
IgA: immunoglobulins that bind bacteria and induce immune reactions
Defensins: Antimicrobial polypeptides, form pore complexes on cell membranes
Mucins: modulate bacteria adhesion to oral tissues (teeth)

5

What are mucins?

lubricants in saliva
anti-microbial
found throughout GI tract
highly O-glycosylated

6

What are some ionic components of saliva?

high HCO3- neutralizes bacterial produced acids
low Na+ and Cl-

7

Name some viruses that saliva can carry.

Human herpes
Herpes simplex
EBV
Mumps
Rabies
HIV

8

What are some conditions that can cause xerostomia?

Cystic fibrosis: mutant chloride transporters to plasma
Sjogren's syndrome: autoantibodies to salivary gland proteins

9

Three phases of gastric secretion.

1. cephalic
2. gastric
3. intestinal

10

ACh

Stimulates HCl & histamine secretion
Inhibits Somatostatin secretion

11

What stimulates the secretion of gastrin?

Gastrin related peptide

12

What stimulates secretion of somatostatin?

HCl
Gastrin

13

What does somatostatin inhibit?

Gastrin
Histamine
HCl

14

What does histamine do?

Stimulates parietal cell HCl

15

What digests fat?

lingual lipase (salivary glands)
gastric lipase (chief cells)

16

What digest carbohydrates?

a-amylase (ptyalin) - salivary glands

17

What digests proteins?

Pepsinogens (chief cells)

18

What stimulates pepsinogen secretion from chief cells?

ACh
Gastrin
Secretin
CCK

19

What is the reflex that relaxes the stomach wall for storage?

Vaso-vagal reflex

20

What does stretching of the stomach wall by food stimulate?

Myenteric reflexes to increase activity of pylorus pump
Gastrin also stimulates the pylorus pump