Flashcards in Gastrointestinal III Deck (116):
Border between the duodenum and jejunem:
How long is the duodenum?
What are the 3 surface levels of the small intestine?
Plicae curculares (macrovilli)
What is at the bottom of a villus?
Crypt of Liberkuhn
What type of cell is generally found on the surface of the vili?
What's found on their surface?
Surface absorptive cells
Brush border enzymes
Name 4 cell types in a Crypt of Liberkuhn.
What does an enteroendocrine cell secrete?
What do Paneth cells secrete?
(and other bacterial agents)
What morphological cell type is found in the intestine?
Enzymes in the stomach can break down carbs
What degrades polysaccharides into disaccharides and oligosaccharides?
How are glucose and galactose absorbed in the gut?
What type of transport is this?
SGLT-1 cotransporter (w/ Na+)
Secondary active transport
(this goes against conc. gradient)
How does Fructose enter the intestinal cell?
What type of transport is this?
Once in the enterocyte, how do monosaccharides exit to the capillaries?
What type of transport is this?
What does SGLT1 require?
(enters with - goes same direction as glc/galactose)
What is absent is Lactose Intolerance?
*leads to fermentation
How does the stomach break down proteins?
Incompletely denatures with Pepsin
(not broken down into single AA's)
Where does protein break down into individual AA's?
What does this? (2 things)
Aminopeptidases and Proteases
*proteases = active pancreatic enzymes
Name 3 secondary brush border enzymes that break down protein?
How are single AA's and small peptides transported into the enterocyte?
GLUT5 Facilitated diffusion
(same as Frc)
What is the 1st step a Fat Globule goes through once in the duodenum?
(by bile acids)
What 2 things coat an emulsification droplet?
What breaks down an emulsification droplet into 2 FFA's and a monoglyceride?
What do FFA's and Monoglycerides combine with to form micelles?
What coats the micelle?
Fat soluble vitamins (ADEK)
Bile acids coat
Once the Micelle enters enterocyte, how are they repackaged into Chylomicrons?
FFA's and monoclycerides re-form triglycerides
What is a lacteal?
Lymphatic capillary opening
How are chylomicrons secreted into lacteals?
Golgi packages and exocytosis
How does all fat enter the bloodsteam?
(juncture subclavian and jugular veins)
How long does it take after eating a fatty meal for fat to travel through lymph and enter blood?
What is this called?
Within an hour
What is the half-life of a chylomicron?
Less than 60 minutes
Where are chylomicrons removed from the blood?
What do adipose and liver contain large quantities of that allows for fat absorption?
What does Lipoprotein Lipase do to a chylomicron?
Hydrolyzes Triglycerides into FA's and glycerol
What are the 5 classes of lipoproteins?
What does the "density" refer to in categorizing lipoproteins?
VLDL, IDL, LHL, and HDL are sythesized by the...
What type of lipoprotein contains low levels of TG's and high cholesterol and phospholipid?
What type of lipoprotein contains high TG's and moderate cholesterol and phospholipids?
What are the only lipoproteins generally monitored?
LDL and HDL
How do Statins work?
HMG CoA Reductase inhibitors
All statin drugs end in...
What is an adverse effect of statins?
What statin side effect refers to muscle pain or weakness without increased creatine kinase?
What statin side effect entails:
no increase creatine kinase
very high CK
What is the prevalence of muscle complaints while taking statins?
1 in 10
7 risk factors for statin myopathy:
What is the function of high dose Nicotinic Acid/Vita B3/Niacin?
Lowers lipid levels
What are the 3 preparations of Niacin used to lower lipid levels?
No-flush (inositol hexaniacinate; nicinamide)
Niacor is a _____ Niacin.
Niaspan and slo-niacin are _____ Niacins
What is the most potent agent for raising HDL levels?
The exact mechanism of Niacin's lowering lipid levels is poorly understood
By how much does Niacin Lower LDL and increase HDL?
LDL - reduce 5-25%
HDL - increase 15-35%
TG's - 20-50%
What percentage of population is intolerant to Niacin?
This is mediated by?
What blunts the Niacin flushing effect?
NSAID 30 minutes prior
Name 3 Bile Acid Binding Resins:
What 2 effects to Bile Acid binding resins have in the small intestine?
Bile acid reabsorption prevention
*liver increases production because of latter
Resins have little effect on HDL/TG's in blood
By how much can Resins decrease Plasma HDL?
30% with max dose
6 side effects of Bile Acid binding resins:
What can relieve resin side effect symptoms?
Increased dietary/supplemental fiber
7 drugs/substances Bile Acid binding Resins bind:
How can drug-drug interactions be reduced when using Resins?
(take hours after taking medications0
Water absorption in the gut is ______ to solute movement.
How is K+ absorbed?
Passively via solvent drag
What is the active form of Vitamin D that is responsible for Calcium absorption?
What does it do?
Stimulated enterocyte Calbindins
How are fat soluble vitamins absorbed?
Similar to fat
How are most water soluble vitamins absorbed?
What absorbs IF-Vitamin B12 complexes?
How much time does chyme spend in the small intestine?
How are peristalsis and segmentation controlled?
The Vagus nerve regulates what in the intestine?
Secretion pancreatic enzymes
What are the longitudinal bands of the large intestine called?
What are the outpouchings of the large intestine called?
What exists between the Teniae coli?
Where is the appendix?
Large intestine lack villi on the mucosa.
What 4 cells exist in the Crypts of Lieberkuhn of the Large Intestine?
Histologically, the luminal surface of the Large intestine is....
How many different species of bacteria live in the Large intestine?
What accounts for the slightly acidic nature of stool?
Organic acids produced by bacterial fermentation in Large intestine
Many normal intestinal flora have a low pH optimum, while many pathogens favor neutral environments.
Bile salts and certain drugs are metabolized in the Large intestine
Vitamin K, B12, and folic acid are all made by intestinal flora.
4 Mechanisms producing diarrhea:
Increased osmotic load
Decreased absorption time
What causes osmotic diarrhea?
*think lactose intolerance
What type of diarrhea does Cholera produce?
What type of diarrhea includes mucosal diseases?
Parkinson's, MS, hypothyroidism, diabetic neuropathy can all cause constipation
Calcium channel blockers, opiates, anti-cholinergics, diuretics, Fe supplements, aluminum antacids all cause constipation.
There are no structural or biochemical abnormalities in IBS
What is the proposed cause of IBS?
Dysregulation of intestinal motor/sensory functions modulated by CNS
*also stress a factor
What bowel disease can manifest in the mouth?
What does not?
2 Inflammatory bowel diseases:
Both Crohn's and Ulcerative Colitis have a causative agent
Where does Ulcerative Colitis usually occur?
Where does Crohn's disease usually occur?
Ileum and Colon
In Crohn's disease, the bowel wall appears thick but the inflammation is _____
In Ulcerative colitis the bowel wall appears thin but the inflammation is _____
Limited to mucosa/submucosa
What condition results from high intraluminal pressure on weak areas of the bowel wall?
*refers to bumps on the outer colon
In Diverticulosis, the _____ layer herniates through the _____ layer.
When diverticulosis becomes inflamed:
What is associated with complaints of pain in the LLQ?
(also nausea, vomiting, tenderness, fever, elevated WBC)
What defining characteristic does acute appendicites have?
Name 4 mechanical intestinal obstructions:
What is associated with the Valsalva maneuver?
(glottis voluntarily closes, abs and diaphragm contract)
Peptic ulcers, esophageal varices, hemorrhoids, blood clotting disorders all can cause GI tract bleeding
What refers to blood in the vomit?
What type of odorous stools originate from bleeding high in the GI tract?
4 Predisposing factors for Adenocarcinoma of the Colon and Rectum:
Low fiber, high animal fat diet
Taking Niacin at night can reduce negative side effects
Increased dental caries is associated with Crohn's
The ulcerations associated with Colitis can be expressed on the face during a flare up.
Also, oral lesions pop up during symptomatic phase
GERD leads to caries.
*although demineralization does