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Flashcards in Fiser Chapter 30. STOMACH Deck (115)
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1

Stomach transit time

3-4 hours

2

Where in stomach does peristalsis occur?

Just antrum (distal stomach)

3

What sympathetic fibers does gastroduodenal pain get sensed?

T5-10

4

Blood supply of stomach

Celiac: left gastric, CHA, splenic (L gastroepiploic and short gastrics are branches of splenic)

Greater curvature: R and L gastroepiploics, short gastrics. (R gastroepiploic is a branch of GDA)

Lesser curvature: R and L gastrics, R is branch off CHA

5

Stomach mucosa hitso

Simple columnar epithelium

6

Cardia glands versus fundus and body glands

Cardia: mucus secreting

Fundus and body glands:
Chief cells pepsinogen
Parietal cells H+ and IF

7

Chief cells

Pepsinogen (1st enzyme in proteolysis)

8

Parietal cells

H+ and IF

9

What causes H+ release from parietal cells?

Ach (vagus)

Gastrin (G cells in antrum)

Histamine (from mast cells)

Phosphorylase kinase and protein kinase A

10

Achetylcholine and gastrin MoA to increase H+ release

Activates phospholipase (PIP) --> DAG + IP3 to increase calcium -> calcium-calmodulin activated phosphorylase kinase -> increased H+ relaease

11

Histamine MoA to increase H+ release

Histamine activates adenylate cyclase -> cAMP -> activates protein kinase A -> increased H+ release

12

Phosphorylase kinase and proteine kinase A MoA to increase H+ release

They phosphorylate H+/K+ ATPase to increase H+ secretion and K+ absorption

13

How does omeprazole work?

Blocks H+/K+ ATPase in parietal cell membrane (the final pathway for H+ release)

14

What are inhibitors of parietal cells (which release H+)?

Somatotatin

Prostaglandins (PGE1)

Secretin

CCK

15

What does intrinsic factor do?

Binds B12, and then the complex is reabsorbed in the TI

16

Fundus and body glands versus antrum and pylorus glands

Fundus and body: chief cells and parietal cells with pepsinogen and H+ and IF release

Antrum and pylorus: G cells (release gastrin in antrum) and mucus and HCO3- secreting glands; and D cells (secrete somatostatin)

17

Why is an antrectomy helpful for ulcer disease?

G cells release gastrin (taken out)

18

What inhibits and stimulates G cells

G cells release gastrin

Inhibited by H+ in duodenum

Stimulated by amino acids and acetylcholine

19

What do D cells do?

Secrete somatostatin, which inhibits gastrin and H+ release

20

What do Brunner's glands do?

Secrete alkaline mucus

(in duodenum)

21

Antral and duodenal acidification causes what?

Somatostatin, CCK, and secretin release

22

MCC rapid and delayed gastric emptying

Rapid: previous surgery, ulcers

Delayed: DM, opiates, anticholinergics, hypothyroid

23

Trichobezoars and phytobezoars

Trychobezoars: Hair, hard to pull out, EGD generally inadequate and likely need gastrostomy and removal

Phytobezoars: Fiber, often in diabetics with poor gastric emptying, tx with enzymes, EGD and diet changes

24

Dieulafoy's ulcer

vascular malformation that can bleed

25

Menetrier's disease

Mucous cell hyperplasia, increased rugal folds

26

Nausea without vomiting, severe pains

Gastric volvulus, usually organoaxial

Associated with type 2 (paraesophageal) hernia

Tx: Reduction and Nissen

27

Hematemesis following severe retching

Mallory-Weiss tear

EGD with hemo-clips; Tear is usually on lesser curvature near GEJ

Bleeding often stops spontaneously, if continued bleeding may need gastrostomy and vessel oversewing

28

Truncal and proximal vagotomies

Both increase liquid emptying by removing vagally mediated receptive relaxation, causing increased gastric pressure that accelerates fluid emptying

Truncal (at level of esophagus): decreases solid emptying; add pyloroplasty to increase solid emptying

Proximal (high selective, divides individual fibers, preserves "crow's foot"): Normal emptying of solids

29

Truncal vagotomy effects

decreased solid emptying (and increased liquid emptying like all vagotomies); decreases acid output by 90%, increases gastrin and gastrin cell hyperplasia; decreases exocrine pancreas function and postprandial bile flow; increases gallbladder volumes, and decreases release of vagally mediated hormons; diarrhea in 40% (most common problem after vagotomy) due to sustained MMCs forcing bile acids into colon

30

MCC problem after vagotomy

Diarrhea