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Flashcards in GI Deck (68):
1

ventral pancreatic bud gives rise to

- pancreatic head and main pancreatic duct, and uncinate process

2

annular pancreas

- the ventral bud abnormally encircles 2nd part of the duodenum, forms a ring of tissue around the duodenum that can cause narrowing

3

pancreas divisum

- ventral and dorsal pancreas fails to fuse at 8 weeks

4

midgut development timeline

- exits through the umbilical ring week 6
- returns to abdominal cavity + rotates around the SMA week 10

5

retroperitoneal structures

SAD PUCKER
- suprarenal (adrenal) glands
- aorta and IVC
- duodenum (2nd - 4th parts)
- pancreas (except tail)
- ureters
- colon (ascending and descending)
- kidneys
- esophagus (lower 2/3)
- rectum

6

which ribs overly the spleen, kidneys and liver

- left 9-11 -- spleen
- right 8-11 -- liver
- left 12 - left kidnet

7

borders of the pleura

- 7, 10, 12
- 7th in midclavicular line, 10th in midaxillary, and 12th in paravertebral

8

falciform ligament - structures contained

- ligamentum teres hepatis (derivative of fetal umbilical vein)
- derivative of ventral mesentery

9

hepatoduodenal ligament - structures contained

- portal traid: hepatic artery, portal vein and CBD
- pringle maneuver - clamp this to prevent bleeding

10

gastrohepatic - structures contained/significance

- gastric arteries
- separates greater and lesser sac on the right

11

gastrosplenic ligament - structures contained and signficance

- short gastrics, left gastroepiploic vessels
- separates greater and lesser sac on the left

12

splenorenal ligament - structures contained

- splenic artery and vein, tail of pancreas

13

layers of the gut wall - inside to outside

- MSMS
- mucosa (epithelium, lamina propria and muscularis mucosa)
- submucosa (include submucosal nerve plexus -- Meissner)
- muscularis externa (includes myenteric nerve plexus -- Auerbach)
- serosa

14

crypts of Lieberkuhn

- simple tubular glands that rest atop muscular mucosa
- present in the duodenum, jejunum, ileum and colon

15

Brunner glands

- secrete alkaline mucus into the crypts, then into the lumen
- present in the duodenal submucosa
- hypertrophy seen in peptic ulcer disease

16

peyer patches

- present in the ileum

17

plicae circularis

- in the jejunum and ileum

18

goblet cells

- in the ileum and colon
- larges number in the small intestine are in the ileum

19

SMA syndrome

- when the transverse portion of the duodenum is entrapped between the SMA and aorta, causing intestinal obstruction
- angle diminishes to < 20 degrees
- precipitated by conditions that lower mesenteric fat (low body weight, severe burns, bed rest, pronounced lordosis)

20

esophageal varices connect

- left gastric vein (portal) and esophageal veins (systemic)

21

caput medusae connects

- umbilical veins (portal) and epigastric veins (systemic)

22

rectal varices connect

- superior rectal vein (portal) to inferior/middle rectal veins (systemic)
- will drain into internal pudendal veins and internal iliacs to react IVC

23

Zone 1 of the liver (periportal)

- affected first by viral hepatitis and ingested toxins

24

Zone 3 of the liver (centrilobular)

affected 1st by ischemia, contains cytochrome p450 system, most sensitive to metabolic toxins, site of alcoholic hepatitis

25

CCK

- produced in the I cells in the duodenum + jejunum
- actions: inc pancreatic secretions, inc gall bladder contraction, inc sphincter of Odi relaxation, and decrease gastric emptying
- increased by fatty acids, amino acids
- CCK acts on neural muscarinic pathways to cause pancreatic secretion

26

gastrin

- G cells (antrum of the stomach)
- actions: increase gastric H+ secretion, growth of gastric mucosa, increased gastric motility
- regulation: increased by stomach distention, alkalinization, amino acids, peptides and vagal stimulation, decreased by stomach pH < 1.5
- increased in Zollinger-Ellison syndrome, PPI use and pernicious anemia
- phenylalanine and tryptophan are potent stimulators

27

glucose dependent insulinotropic peptide (GIP)

- secreted by K cells (duodenum, jejunum)
- actions: exocrine -- decreases gastric H+ secrtion, endocrin -- increases insulin release
- regulation: increased by fatty acids, amino acids, oral glucose
- this is why oral glucose is more rapidly utilized than IV glucose

28

motilin

- source: small intestine
- actions: produces MMCs
- increases in fasting state
- motilin receptor agonists (erythromycin_ are used to stimulate intestinal peristalsis

29

secretin

- source: S cells in the duodenum
- actions: increase pancreatic HCO3-, decrease gastric acid secretion and increase bile secretion
- regulation: increased by acid and fatty acids in the lumen of the duodenum

30

somatostatin

- inhibitory hormone secreted by D cells in the pancreatic islets and GI mucosa
- decreases gastric acid and pepsinogen secretion, decreased gallbladder contraction, decreases insulin and glucagon release
- increased by acid, decreased by vagal stimulation
- has anti-growth effects
- H pylori leads to chronic antral inflammation that decreases the number of D cells

31

VIP

- source: PS ganglia in the sphincters, gall bladder and small intestine
- increases intestinal water and electrolyte secretion, increased relaxation of intestinal smooth muscle and sphincters
- increased by distention and vagal stimulation, decreased by adrenergic input

32

VIPoma

- non-alpha, non-beta islet cell tumor that secretes VIP
- copious Watery Diarrhea, Hypokalemia, and Achlorhydia (WDHA)

33

intrinsic factor

- source: parietal cells (stomach)
- vitamin B12 binding protein required for uptake in the terminal ileum
- AI destruction of parietal cells --> chronic gastritis and pernicious anemia

34

gastric acid

- secreted by parietal cells in the stomach
- action -- decreases stomach pH
- secretion increased by histamine, Ach and gastrin
- secretion decreased by somatostatin, GIP, prostaglandin, secretin

35

gastrinoma

gastrin secreting tumor that causes high levels of acid secretion and ulcers (duodenal and jejunal) refractory to medical therapy

36

pepsin

- secreted by chief cells of the stomach
- action - protein digestion
- regulation - increased by vagal stimulation, local acid
- inactive pepsinogen in cleaved to pepsin by H+

37

cells in the body of the stomach

chief cells and parietal cells

38

cells in the antrum of the stomach

G cells, mucous cells and D cells

39

cells in the duodenum

I, S and K cells

40

gastric parietal cell mediators

- Ach (via M3) and gastrin (via CCKb) stimulate Gq and increases IP3/Ca, which increases H/K ATPase activity
- histamine binds H2 receptor and increases cAMP through Gs, which increases H/K ATPase activity
- prostaglandins, misoprostol and somatostatin decrease cAMP via Gi, decreasing H/K ATPase activity

41

trypsinogen

- converted to trypsin (protease) by enterokinase/enteropeptidase and then goes on to cleave/activate other enzymes
- enteropeptidase deficiency: impaired trypsin formation leading to diarrhea, growth retardation and hypoproteinemia
- serine peptidase inhibitor secreted by acinar cells (trypsin inhibitor)

42

D-xylose absorption test

distinguishes GI mucosal damage from other causes of malabsorption
- would be normal in pancreatic insufficiency/after pancreatic surgery

43

carb absorption

- glucose and galactose taken up by SGLT1
- fructose taken up by GLUT5
- all transported to the blood by GLUT 2

44

iron absorbed in the ....

duodenum
- so pts s/p gastrojejunostomy will need Fe supplements

45

folate absorbed in the ....

jejunum and ileum

46

B12 is absorbed in the ...

terminal ileum along with bile acids, requires IF

47

peyer patches

- in the lamina propria and submucosa of the ileum
- contain M cells that sample antigens
- IgA secreting plasma cells produce secretory IgA that deal with the intraluminal antigen

48

bile

- made by cholesterol 7-a hydroxylase
- functions: digestion and absorption of lipids and fat-soluble vitamins, cholesterol excretion, antimicrobial activity (via membrane disruption)

49

heme oxygenase

- breaks heme down to biliveridin
- responsible for the green discoloration of bruises

50

pleomorphic adenoma

- benign mixed tumor (stromal and epithelial)
- the most common salivary gland tumor, usually involves the parotid gland
- painless, well-circumscribed, mobile mass
- recurs if incompletely excised, which happens a lot because it has irregular borders

51

warthin tumor

- aka pupillary cystadenoma lymphomatosum
- benign cystic tumor with germinal centers (lymphoid tissue)
- usually involves the parotid gland

52

mucoepidermoid carcinoma

- most common malignant tumor and has mucinous and squamous components
- typically presents as painless, slow-growing mass
- commonly involves the parotid and affects the facial nerve

53

achalasia

- inability to relax the LES because of loss of the myenteric (Auerbach) plexus
- progressive dysphagia to solids and liquids
- increased risk of SCC
- can be 2/2 Chagas disease

54

eosinophilic esophagitis

infiltration of eosinophils in the esophagus in atopic pts
- food allergens --> dysphagia, heartburn, strictures
- unresponsive to GERD therapy

55

esophagitis

- associated with reflux, infection in immunocompromised or chemical ingestion
- candida - white psuedomembrane
- HSV-1 - punched out ulcers
- CMV - linear ulcers

56

Plummer Vinson Sydnrome

- triad of dysphagia (due to esophageal webs), iron deficiency anemia and glossitis (beefy red tongue)

57

barrett esophagus

- glandular metaplasia that replaces nonkeratinized squamous epithelium with intestinal epithelium (nonciliated columnar with goblet cells)
- increased risk for esophageal adenocarcinoma

58

esophageal carcinoma

- adeno most common in the US, squamous everywhere else
- adeno on the bottom 1/3
- adeno RF: barretts, cigarettes, fat, GERD
- squamous RF: alcohol, cigarettes, hot drinks, lye ingestion, esophageal webs, diverticula, achalasia
- squamous on the top 2/3
- nodes they go to: upper 1/3 --> cervical nodes, middle 1/3 --> mediastinal, bottom 1/3 --> celiac/gastric

59

acute gastritis

- disruption of the mucosal barrier leads to inflammation
- can be caused by stress, NSAIDs, alcohol, uremia, burns (Curling ulcer), brain injury (Cushing ulcer), and chemo

60

Curling Ulcer

- due to severe burns --> decreased plasma volume --> sloughing of the gastric mucosa

61

Cushing ulcer

- due to increased ICP --> increased vagal stimulation --> increased Ach action on parietal cells --> increased acid

62

type A chronic gastritis

- autoimmune attack on parietal cells, pernicious anemia, and achlorhydria (low acid production by the stomach leads to increased gastrin secretion and G cell hyperplasia in the antrum)
- associated with other AI disorders

63

type B chronic gastritis

most common type, associated with H pylori infection
- increased risk of MALT lymphoma, gastric adenocarcinoma and ulcers

64

mentrier disease

- gastric hypertrophy with protein loss, parietal cell atrophy, and increased mucous cells
- precancerous
- rugae of the stomach are so hypertrophied that they look like brain gyri

65

stomach cancer - intestinal type

- associated with H pylori, nitrosamines, tobacco, achlorhydria, AI chronic gastritis
- commonly on lesser curvature, looks like ulcer with raised margins
- pts with blood type A have higher risk

66

stomach cancer - diffuse type

- not associated with H pylori
- signet ring cells
- will infiltrate the stomach wall and cause thickening/leathery appearance (linitis plastica)

67

gastric ulcer

- pain Greater with meals
- usually on the lesser curvature - if they bleed it comes from the left gastric artery
- H pylori 70% of the time, also NSAIDs
- increased risk for carcinoma, happen in older people

68

duodenal ulcer

- pain Decreases with meals
- H pylori almost always
- associated with Z-E syndrome
- generally benign
- can see hypertrophy of the brunner glands
- if they bleed it is the gastroduodenal artery