Term
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Definition
| G Cells (Antrum of Stomach |
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Term
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Definition
Increases:
1) Gastric H+ Secretion
2) Growth of Gastric Mucosa
3) Gastric Motility |
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Term
| Gastrin Regulation (up regulate) |
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Definition
1) Stomach Distension (bolus entering)
2) Alkalinization (loss of physiologic low pH)
3) Amino Acids (particularly Phenylalinine and Tryptophan)
4) Peptides (gastrin releasing peptide GRP)
5) Vagal Stimulation (vago-vagal reflex) |
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Term
| Gastrin Regulation (negative) |
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Definition
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Term
| What syndrome results in the overproduction of Gastrin? |
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Definition
Zollinger-Ellison Syndrome
Caused by non beta cell islet tumor and results in ulceration |
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Term
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Definition
| I Cells- Duodenum and jejunum |
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Term
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Definition
Increases:
1) Pancreatic Secretions
2) Gallbladder contraction
Decreases:
1) Gastric Emptying
2) relaxes the sphincter of Oddi |
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Term
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Definition
| Increased by fatty acids and amino acids |
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Term
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Definition
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Term
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Definition
Increases:
1) Pancreatic HCO3- secretion
2) Bile Secretion
Decreases:
1) Gastric Acid Secretion |
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Term
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Definition
Increased by
1) Fatty acids in lumen of duodenum
2) Increased acidity |
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Term
| Why are secretin's actions necessary (what's the point of bicarbonate ion?) |
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Definition
| Secretin releases bicarbonate into the duodenum. This neutralizes the gastric acid and restores a pH at which pancreatic enzymes can functionally metabolize their products. |
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Term
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Definition
D-Cells
Pancreatic Islets
GI Mucosa |
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Term
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Definition
Decreases:
1) Production of gastric acid and pepsinogen
2) pancreatic and small intestine fluid secretion
3) gallbladder contraction
4) Insulin and glucagon release |
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Term
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Definition
Increased by
1) acidity
Decreased by
1) Vagal stimulation |
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Term
| Somatostatin: Excitatory or inhibitory? |
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Definition
| Inhibitory-has antigrowth hormone effects in digestion and absorption of suibstances needed for growth. |
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Term
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Definition
| K Cells-Duodenum and Jejunum |
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Term
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Definition
| Decrease Gastric Acid Secretion |
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Term
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Definition
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Term
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Definition
| Increased by Fatty acids, amino acids, and oral glucose |
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Term
| GIP-Is oral or IV glucose used more rapidly? |
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Definition
| Oral- Insulin has a more dramatic response to oral glucose than IV glucose. This leads to increased GLUT4 recptors and faster utilization in the body. |
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Term
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Definition
| Parasympathetic Ganglia in Gi Tract (GB, Sphincters, and SI) |
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Term
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Definition
Increases:
1) Intestinal water and electrolyte secretion
2) Relaxation of intestinal smooth muscle |
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Term
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Definition
Increased by distension and vagal stimulation
Decreased by adrenergic stimulation |
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Term
| What is a VIPoma and its consequenses? |
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Definition
| VIPoma-non alpha non beta cell islet tumor that secrets VIP. This results in copious diarrhea, and possible cardiac arrythmias due to hypokalemia infants are particularly at risk of cardiac effects of diarrhea. |
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Term
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Definition
| Relaxes Smooth Muscle including LES |
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Term
| How does a loss of NO effect GI motility |
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Definition
| Loss of NO results in increased LES Tone which can lead to achalasia. |
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Term
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Definition
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Term
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Definition
| Prodcues Migrating Motor Complexes- periodic waves of contraction that empty the intestine even while fasting |
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Term
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Definition
| Increased in a fasting state |
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Term
| What is the effect of a motilin receptor agonist? |
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Definition
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Term
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Definition
| Parietal Cells of the Stomach |
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Term
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Definition
| Binds Vitamin B12 for uptake in the terminal ileum |
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Term
| Loss of Intrinsic factor or IF producing parietal cells can lead to what deficiency and disease? |
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Definition
| Loss of Vitamin B-12 and pernicious anemia. |
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Term
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Definition
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Term
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Definition
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Term
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Definition
Increased by Histamine, ACh, Gastrin
Decreased by somatostatin, GIP prostaglandin, and secretin |
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Term
| Gastric Acid-What is Gastrinoma? |
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Definition
| Gastrin secreting tumor that causes high levels of acid and ulceration |
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Term
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Definition
| Chief Cells (secreted as pepsinogen and cleaved by decreased pH) |
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Term
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Definition
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Term
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Definition
| Increased by Vagal stimulation and acid |
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Term
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Definition
| pepsinogen-proenzyme until it is in the acidity of the stomach |
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Term
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Definition
| Mucosal Cells of stomach, duodenum, salivary glands, pancreas and Brunners Glands of the duodenum |
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Term
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Definition
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Term
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Definition
| Incrased by Pancreatic and biliary secretion of Secretin |
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Term
| What is important about Bicarbonate in the stomach? |
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Definition
| trapped in the mucous layer in gastric epithelium and protects cells from acidic damage. Loss of mucous can lead to ulceration. |
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Term
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Definition
| Salivry glands, and pancreas |
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Term
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Definition
| Converts starch to disaccharides |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
| Pancreas-secreted as zymogens |
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Term
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Definition
Stomach Mucosal Cells
Intestinal Mucosal cells
Mucous produced by Mucosal cells, go figure |
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Term
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Definition
| Barrier to acid and prevention of autodigestion |
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Term
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Definition
| Lubrication to reduce damage to intestinal epithelium |
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Term
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Definition
Hepatocytes (primary)
Gut Flora (secondary converted from primary) |
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Term
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Definition
| Emulsify Fats in duodenum to facilitate micelle formation. Formation of micelles increased efficiency of fat absorbtion |
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Term
| Production of Bile Salts is the primary route of excretion of which molecule? |
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Definition
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Term
| What is the enzyme involved in the rate limiting step of bile acid (salt) synthesis |
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Definition
| Cholesterol 7-alpha hydroxylase converts cholesterol to form 7-alphahydroxycholesterol. Deficiency of this enzyme results in increased amounts of gallstones. |
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Term
| What percenatage of Bile Salts are reabsorbed in the digestive system through the enterohepatic circulation and where does most of this happen? |
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Definition
| 95% of bile salts are reabsorbed to the enterohepatic circulation via the small intestine. Pharmacologic sequestrants of bile acid prevent this reuptake of bile acid, leading to increased loss of bile salts, leading to lower levels of systemic cholesterol. |
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