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Flashcards in Digestion Overview Deck (46):
1

Function of Oral cavity, teeth and tongue

Mechanical processing, moistening, mixing with salivary secretions

2

Function of Salivary glands

Secretion of lubricating fluid containing enzymes that break down carbohydrates

3

Function of Liver

Secretion of bile (lipid digestion), storage of nutrients, many other vital functions

4

Function of pharynx

Muscular propulsion of materials into the esophagus

5

Function of gallbladder

storage and concentration of bile

6

Function of esophagus

transport of materials to the stomach

7

Function of pancreas

Exocrine cells secrete buffers and digestive enzymes
Endocrine cells secrete hormones

8

Function of Stomach

chemical breakdown of material via acid and enzymes
Mechanical processing through muscular contraction

9

Function of Large Intestine

Dehydration and compaction of undigestiible material in prep for elimination

10

Function of Small Intestine

enzymatic digestion and absorption of water, organic substrates, vitamins and ions

11

Major salivary glands

Parotid
Submandibular
Sublingual

12

Function of the 2 main salivary glands

Lubrication
Oral hygiene
Digestion (amylase, lipase)

13

Lipase breaks down

fats

14

Amylase breaks down

carbs

15

How does saliva secretion occur?

Cl- is excreted into apical membrane of secretary epithelial cells building an electrochemical gradient which is maintained by Na-K-ATPase in the basolateral membrane
When Cl- is excreted, it draws Na, K, and Ca from the plasma into the lumen
This flux generates an osmotic gradient that draws water into the saliva until the osmolality of secretion equals the plasma

16

What are the salivary glands controlled by?

Autonomic nervous system

17

How are the salivary glands controlled?

Sympathetic and parasympathetic innervations

18

What does the sympathetic stimulation lead to?

Secretion of small volume of viscous saliva containing high enzyme concentration
"dry mouth"

19

What does parasympathetic stimulation lead to?

Accelerates secretion by all the glands resulting in large amounts of watery saliva

20

Phases of swallowing

Buccal (chewing)
Pharyngeal
Esophageal

21

Plica function

Have villi on them to help food flow in one direction
Help with absorption

22

Define Peristalsis

Combination of circular and longitudinal muscles to move the food

23

How do the muscles contract?

CIrcular contract first to mix and move the food and then longitudinal contract ahead of the food and then circular contract again to propel it down

24

Fundus where and what does it do?

Top of the stomach where gastric acid is produced

25

Parietal cells secretion

Produce HCL and intrinsic factor

26

Mucous cell secretion

Mucus which protects the epithelia from the acidic gastric acid
- Lack = ulcers

27

Chief cells secretion

Pepsinogen which is the precursor to pepsin which helps break down the food
Also produced in Brunner's gland of duodenum

28

Enteroendocrine cell secretion

Hormones

29

G cell secretion

Gastrin

30

A cells secretion

Glucagon

31

D cell secretion

Somatostatin

32

Gastric lipase secretion

Helps break down fat

33

Acid secretion depends on:

Carbonic anhydrase and chloride/bicarbonate exchange

34

FInal pH of the stomach

1.5-3.5

35

Hydrochloric acid does what

Lowers the pH of gastric juice
Kills microorganisms
Breaks down cell walls and connective tissues in food
Activates chief cells (pepsinogen)

36

Acid secretion is inhibited by:

Somatostatin and prostaglandins (PGE2)

37

Enterochromaffin-like cells function

After gastrin stimulation due to food enter the fundus, release histamine which stimulates acid production

38

Parts of the small intestine:

Duodenum
Jejunum
Ileum

39

Duodenum

Where food enters
Acidic in nature
Reabsorption

40

Jejunum

Longest portion

41

Ileum

Connected to the large intestine (colon) via the cecum

42

Parts of the Large intestine

Ascending
Transverse
Descending

43

Goblet cells produce

Fat

44

Two ducts come together, what are they?

Common bile duct (gallbladder)
Pancreatic duct

45

Passage of food takes:

4-9 hours to reach the cecum
12-25 hours to travel from cecum to rectum

46

Chyme and water:

500-1500 mL of chyme enters large intestine
Less than 200 mL water is lost in feces