19a) GI function Flashcards
1
Q
function of sphincters
A
Serve to compartmentalize the gut
2
Q
3 major stomach regions
A
Cardiac (with fundus)
Body
Pylorus
3
Q
cardiac/fundus region secretions
A
mucus
group II pepsinogens
4
Q
body stomach region secretions
A
mucus (surface epis)
HCl (parietal)
IF (parietal)
groups I and II pepsinogens (chief)
serotonin (enterochromaffin)
5
Q
areas of pylorus
A
Antrum
Pyloric canal
Sphincter
6
Q
pyloric region secretions
A
Mucus
Group II pepsinogen
Serotonin
Gastrin
Other hormones
7
Q
only stomach site of HCl
A
body
8
Q
surface epi/goblet cells secrete…
A
mucus
9
Q
parietal cells secrete…
A
HCl
IF
10
Q
chief cells secrete…
A
groups I and II pepsinogen
11
Q
enterochromaffin cells secrete…
A
serotonin
12
Q
delivers bile and enzymes into the duodenum
A
Pancreaticobiliary duct
13
Q
Nerves located in the gut wall assist in controlling…
A
propulsion and fluid regulation
14
Q
Involuntary control of GI activities for each region are modulated via …
A
extrinsic neural inputs
15
Q
2 principal GI functions
A
Assimilation of nutrients
Elimination of waste
16
Q
sterilizes upper gut
A
gastric acid
17
Q
Distal stomach has … to propel solid food against the pylorus
A
phasic contractions
18
Q
contents of pancreatic juice
A
digestive enzymes
bicarbonate
19
Q
——- absorbs vitamin B12 and bile acids
A
ileum
20
Q
Small intestines help in waste elimination by removing bile from…
A
erythrocyte degradation
toxins metabolized
unaltered medications
cholesterol
21
Q
terminal end of SI
A
ileocecal junction
22
Q
Stool is dehydrated by…
A
colonic mucosa cells
23
Q
Fermentation of …. in colon by bacterial colonization
A
undigested carbs and short-chain fatty acids
24
Q
GI regulatory peptides influence…
A
- Motility
- Secretion
- Digestion
- Absorption
- Bile flow and secretion of pancreatic hormones
- Vascular wall tonicity, blood pressure, and cardiac output
25
main 5 gastric regulatory peptides
* Cholecystokinin
* Gastrin
* Secretin
* Vasoactive intestinal polypeptide
* Glucose-dependent insulinotropic peptide (gastric inhibitory polypeptide)
26
Linear polypeptide with multiple molecular forms
CKK
27
CKK
cholecystokinin
28
from I cells of the upper small intestinal mucosa
CKK
29
CKK functions
* Regulates gallbladder contractions
* Increases **motility**
* **Stimulates gastric HCL and pepsinogen secretion**
* Pancreatic **bicarbonate secretion**
* Pancreatic growth
* Relaxation of the sphincter of Oddi
* Secretion from duodenal glands
* Regulating appetite
30
Formed after cleavage of a single precursor (-----------) which contains 101 amino acids
Molecular forms include big, little, and mini
**gastrin**
preprogastrin
31
from endocrine cells (G cells) of the antral mucosa
gastrin
32
gastrin functions
* Stimulates release of **gastric acid** in the stomach
* Promotes the secretion of **pepsinogen and intrinsic factor (IF)**
* Stimulates release of **secretin** by the small intestine
33
gastrin released in response to...
- Antral distention (stomach stretching)
- Amino acids, peptides, and polypeptides from partially digested proteins in the stomach
also...
Alcohol
Caffeine
Insulin-induced hypoglycemia
Infusion of calcium
Stimulation of the vagus nerve caused by smelling, tasting, chewing, and swallowing food
34
from granular S cells located primarily in the duodenum
secretin
35
secretin function
- Stimulates the pancreas to secrete an increased volume of fluid with high **bicarbonate** content
- Stimulates PTH
- **Inhibits gastrin** secretion
- **Reduces motility**
- **Reduces insulin**
36
VIP
Vasoactive Intestinal Polypeptide
37
secretin released in response to...
gastric HCL coming into contact with S cells
38
neurotransmitter from nervous system and gut
short duration of action
VIP
39
VIP functions
* **Vasodilation and relaxation of smooth muscles** of the circulatory and genitourinary systems and the gut
* Increase **water and electrolyte secretion** from the pancreas and gut
* Release of hormones from the pancreas, gut, and hypothalamus
* **Inhibition of gastrin** and gastric acid secretion
* Stimulation of lipolysis, glycolysis, and bile flow
40
GIP
Glucose-Dependent Insulinotropic Peptide
Gastric Inhibitory Polypeptide
41
from K cells located in the duodenal and jejuna mucosa
GIP
42
GIP levels are increased by ...
oral administration of **glucose** and **triglycerides**
**intraduodenal infusion** of solutions containing a mixture of amino acids
43
GIP functions
- Stimulates insulin secretion (**insulinotropic**)
- Increases intestinal fluid and electrolyte secretion
- **Inhibits gastric acid, pepsin, and gastrin** secretions
44
characteristics of Zollinger-Ellison
* fulminate peptic **ulcers**
* large amounts of **gastric hypersecretion**
* non-β-islet-cell **tumors** of the pancreas
45
..... that secretes gastrin, which causes gastric acid hypersecretion, are related to Z-E syndrome
gastrinomas/neuroendocrine tumors
46
Z-E syndrome usually results in...
PUD
diarrhea
47
2 causes of PUD
- H. pylori
- NSAID use
48
Increases HCl production, inflammatory cytokines, tissue necrosis factor-alpha, B-Cell response that consists of IgG and IgA antibodies
H.pylori
49
Stool samples will have low pH and contain glucose
lactase deficiency
50
Lactase deficiency differential diagnosis requires .... in conjunction with the lactose tolerance test
oral glucose tolerance test
51
Disorder that leads to chronic diarrhea when there is...
- ileal disease (Crohn’s disease)
- after resection of the terminal ileum
- cholecystectomy
- IBS
bile salt malabsorption
52
bile acids
Glycocholic acid and taurocholic acid
| Exist as taurine or glycine conjugates (salts)
53
bile acid function
- Act as surface-active agents to form micelles
- Facilitated digestion of triglycerides
- Absorption of cholesterol and fat-soluble vitamins
54
Condition in which large amounts of serum proteins pass into the bowel lumen and ultimately into the feces
PLE
55
hypoalbuminemia
hypoalbuminuria
PLE
56
PLE associated with...(3)
- Inflammation or **ulceration** of bowel
- Intestinal **lymphatic** system is obstructed
- Altered **immune** status and some food allergies
57
Characterized by transmural inflammation of the GI tract
Crohn's disease
58
likely to overgrow in SI
Escherichia coli and Bacteroides species
59
- conjugated bile salt deficiency; fat malabsorption
- B12 deficiency
- abdominal pain, diarrhea, and steatorrhea
bacterial overgrowth in SI
60
Impaired esophageal body peristalsis and incomplete lower esophageal sphincter relaxation
achalasia
61
Symptomatic delay in gastric emptying of solids or liquid meals secondary to impaired gastric motility
gastroparesis
62
Diffusely impaired colonic propulsion or by outlet abnormalities
constipation
63
Result of an inappropriate T-cell-mediated immune response to diet
Celiac's disease (Gluten)
64
toxic parts of gluten to Celiac pts
gliadins
hordeins
secalins
65
Leads to intestinal epithelial damage and release of tissue **transglutaminase**
celiac
66
---------- cancer (3rd highest for new cases of cancer)
---------- cancer (↑ alcohol and tobacco use)
colorectal
esophageal
67
Rare, but most common GI neuroendocrine tumor
Age range 20-90 years old, peak 50-70 years
carcinoid tumor
68
- Arise from enterochromaffin cells of the GI tract
- Appear as well-circumscribed, round, submucosal lesions, and the cut surface appears yellow due to lipid content
carcinoid tumor
69
Cells can be stained with potassium chromate (chromaffin) due to the presence of serotonin in the cell
carcinoid tumor
70
Classification based on origin: foregut, midgut, hindgut
carcinoid tumor
71
lab tests for PUD
* Helicobacter pylori biopsy
* serum IgA, IgG
* cytotoxic associated antigen A (CagA)
* NSAID levels
72
celiac lab tests
- **Gliadin** antibodies (IgA & IgG)
- IgA-antitissue **transglutaminase** antibody
- IgA-**endomysial** antibody
73
Z-E syndrome lab tests
Basal acid output
gastrin
74
carcinoid tumor lab test
5-hydroxyindolacetic acid
75
PLE lab test
Alpha-1-antitrypsin
76
High Fasting gastrin levels **>500** pg/mL (<100)
High Basal gastric acid output **>25** mmol/h (2-5 mmol/h)
Z-E syndrome
77
Urea breath tests use radio-labeled carbon or carbon dioxide
PUD (H. pylori)
78
POC uses whole-blood to measure IgG antibodies, serum for IgA, IgG, and cytotoxin-associated gene A proteins
PUD (H. pylori)
79
lactose tolerance test >30 mg/dL above baseline
excludes lactase def.
80
principle of lactose breath hydrogen test
Hydrogen is not an end product of mammal metabolism, but **breath hydrogen is derived from bacterial metabolism** in the intestinal tract that is absorbed into the circulation and exhaled in the breath.
81
lactose breath hydrogen results
Normal breath hydrogen: 10 ppm (uL/L)
Lactose malabsorption: >20 ppm (uL/L)
82
Less frequent procedure uses 14C-xylose or 14C-glycocholic acid
bacterial overgrowth
83
Whole-body scan after oral synthetic radioactive selenohomocholyltaurine (SeHCAT)
pos?
bile salt malabsorption
+ if retention of oral dose <10%
84
Measurement of 7α-hydroxy-4-cholesten-3-one
tandem mass spec
bile salt malabsorption
85
fecal clearance of α-1-antitrypsin test
pos?
PLE test
PLE patients: Fecal clearance of AAT ↑ and the amount of protein loss ↑
