Digestion and Absorption in the GI Tract Flashcards by Deleted Deleted

How does lactase deficiency lead to increased osmotic pressure in the lumen?

If lactase is deficient, then lactose is unable to be broken down and absorbed. Lactose itself is nonabsorbable and holds water in the lumen which cause the increase in osmotic pressure

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What does lactose that rermains in the lumen get fermented into? (2)

A. Ethane and H2O

B. Methane and H2O

C. Methane and H+

D. None of the above

Methane and H+

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What are the 3 primary sugars in the human diet?

Sucrose. Lactose. Starch

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T/F: Amylose, Glycogen, EtOH/alcohol, lactic acid, pyruvic acid, pectins, and dextrins are all secondary sugars found in the human diet

True

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Where does carbohydrate digestion occur?

A. Mouth and stomach

B. Stomach and Small Intestine

C. Mouth and Small Intestine

D. Mouth and Large Intestine

Mouth and Small Intestine

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Pancreatic amylase and Salivary amylase found in the small intestine and mouth respectively break down starch into what?

Maltose and 3-9 glucose polymers

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Brush border enterocytes finish the breakdown of disacharides to monosacharides because only monosacharides are absorbed in the small intestine. All of the following disacharides get broken down into glucose and glucose, EXCEPT for which of the following? Select all that apply and express what monosacharides they break down into.

A. alpha-dextrin

B. maltose

C. maltotriose

D. trhalose

E. lactose

F. sucrose

Lactose: glucose and galactose

Sucrose: glucose and fructose

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Which of the following monosacharides utilize secondary active transport and facilitated diffusion to traverse through epithelial cells of the small intestine?

A. Galactose and Glucose

B. Galactose and Fructose

C. Fructose and Glucose

D. Glucose only

Galactose and Glucose

NOTE: Fructose only moves through via facilitated fusion

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In the absorption of carbohydrates, Na/K ATPase in the basolateral membrane is necessary for creating a concentration gradient that allows glacatose, glucose, and fructose to be transported though.

What transport mechanisms are utilized by the big three to get into the cell from the lumen?

What transport mechanism is utilized by the big three to get out of the cell and into the blood?

Galactose and Glucose: SGLT1

Fructose: GLUT5

Glucose, Galactose, Fructose: GLUT2

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T/F: Dxylose is a pentose monosacharide that is used to test the absorbative capacity of the proximal small intestine due to its ability to utilize SGLT1 or be absorbed via passive diffusion

True

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The following diseases result due to either a deficiency of pancreatic enzymes, or a defect in the transport of intestinal epithelial cells. Which of the diseases is specifically due to deficiency in pancreatic enzyme proteases like trypsinogen?

A. Hartnup disease

B. Cystinuria

C. Chronic Pancreatitis

D. Cystic Fibrosis

E. Congenital Trypsin Absence

Chronic Pancreatitis

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The following diseases result due to either a deficiency of pancreatic enzymes, or a defect in the transport of intestinal epithelial cells. Which of the diseases is due to loss of all pancreatic enzymes resultin in the absence of trypsin?

A. Hartnup disease

B. Cystinuria

C. Chronic Pancreatitis

D. Cystic Fibrosis

E. Congenital Trypsin Absence

Congenital Trypsin Absence

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The following diseases result due to either a deficiency of pancreatic enzymes, or a defect in the transport of intestinal epithelial cells. What diesase is caused by a defect in SLG3A1 or absence of dibasic transporter SLC7A9 meaning we’d probably see large amounts of cysteine, lysine, arginine, ornithine in the feces?

A. Hartnup disease

B. Cystinuria

C. Chronic Pancreatitis

D. Cystic Fibrosis

E. Congenital Trypsin Absence

Cystinuria

defect in SLG3A1 or SLC7A9

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The following diseases result due to either a deficiency of pancreatic enzymes, or a defect in the transport of intestinal epithelial cells. What diesase do we see a failure to absorb neutral AAs like tryptophan or its by-products like serotonin? (symptoms resemble niacin deficiency)

A. Hartnup disease

B. Cystinuria

C. Chronic Pancreatitis

D. Cystic Fibrosis

E. Congenital Trypsin Absence

Hartnup disease

diarrhea, mood changes, neurological problems, red-scaly rash, photosensitivity, short

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The following diseases result due to either a deficiency of pancreatic enzymes, or a defect in the transport of intestinal epithelial cells. What disease often results from mutation of the CFTR Cl- channel on pancreatic duct cell’s apical border leading to loss of HCO3 secretion for neutralizing pH in duodenum?

A. Hartnup disease

B. Cystinuria

C. Chronic Pancreatitis

D. Cystic Fibrosis

E. Congenital Trypsin Absence

Cystic Fibrosis

or Acute/Chronic Pancreatitis

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Which of the following is not essential for protein digestion?

A. Stomach; pepsin

B. Pancreas; trypsin, chymotrypsin, carboxypeptidase, elastase

C. Small intestine: eminopeptidases and dipeptidases

D. All of the above are essential

Stomach; pepsin

Pancreatic and brush border enzyme proteases ALONE can adequately digest ingested proteins

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T/F: Only amino acids, di- or tri- peptides are absorbable

True

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Which of the following pancreatic enzymes work specifically on small peptides?

A. Trypsin and chymotrypsin

B. Carboxypeptidases and chymotrypsin

C. Trypsin and carboxypeptidases

D. All of the above

Trypsin and chymotrypsin

NOTE: Carboxypeptidases cleave AAs into carboxyl ends

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Amino acids are absorbed from the lumen into the cell by apical Na-AA cotransporters that are energized by the actions of the Na/K ATPase located at the basolateral membrane. There are 4 seperate transporters for each AA type. What are those 4 types?

Neutral

Acidic

Basic

Imino

NOTE: once in the cell, they are transported across the basolateral membrane and into the blood via Facilitated diffusion based on there make up (as state above)

What type of transporter found in the apical membrane moves dipeptides and tripeptides into the cell?

A. Na-dependent cotransporter

B. Na-independent cotransporter

C. H+-dependent cotransporter

D. H+- independent cotransporter

H+-dependent cotransporter

NOTE: In the cell cytosolic peptidases break them down into AAs and they exit via facilitated diffusion just like the other AAs

Which of the following is true of Celiac Sprue/Disease? Select all that apply

A. Leads to malabsorption related to deficiencies in folate(B9), iron, calcium, vitamin A, vitamin B12, and vitamin D

B. Damage done to jejunum and ileum

C. Damage done to duodenum

D. Malabsorption of folate(B9) and vitamin B12

Leads to malabsorption related to deficiencies in folate(B9), iron, calcium, vitamin A, vitamin B12, and vitamin D

Damage done to duodenum?

Which of the following is true of Tropical Sprue?

Select all that apply

A. Leads to malabsorption related to deficiencies in folate(B9), iron, calcium, vitamin A, vitamin B12, and vitamin D

B. Damage done to jejunum and ileum

C. Damage done to duodenum

D. Malabsorption of folate(B9) and vitamin B12

Damage done to jejunum and ileum

Malabsorption of folate(B9) and vitamin B12

NOTE: Folate (jejunum) B12 (ileum)

Administration of which of the following substances would increase the amount of time lingual lipase and gastric lipase get to act on TAGs in the stomach?

A. Secretin

B. Ghrelin

C. CCK

D. Gastrin

CCK

Most digestion of fat occurs in the small intesitne with the work of the following pancreatic enzymes. What enzyme is the only one that secreted as a proenzyme and needs to be activated by trypsin first?

A. Pancreatic lipase

B. Cholesterol ester hydrolase

C. Phospholipase A2

D. None of the above

Phospholipase A2

Most digestion of fat occurs in the small intesitne with the work of the following pancreatic enzymes. What enzyme is secreted as an active enzyme, but bile salts keep it inactivated until colipase displaces the bile salt? A. Pancreatic lipase B. Cholesterol ester hydrolase C. Phospholipase A2 D. None of the above

Pancreatic lipase - increase in bile salts will probs keep this thing inactive not good

Most digestion of fat occurs in the small intesitne with the work of the following pancreatic enzymes. What enzyme catalyzes free cholesterol production and hydrolyzes triglycerids to glycerol? A. Pancreatic lipase B. Cholesterol ester hydrolase C. Phospholipase A2 D. None of the above

Cholesterol ester hydrolase

Final products that can be absorbed after fat digestion include what substance? A. Lysolecithin B. Glycerol C. Monoglycerides D. Cholesterol E. Fatty acids F. All of the above

All of the above

Where do bile salts get absorbed? A. Stomach B. Duodenum C. Jejunum D. Ileum

Ileum

Most lipids get absorbed midway through what structure? A. Stomach B. Duodenum C. Jejunum D. Ileum

Jejunum

During fat absorption, once lipids are re-esterfied with FFA's in the SER, they get packaged into chylomicrons with ApoB. These chylomicrons are released via exocytosis into lymphatics at what structure? A. Cistern chyli B. Thoracic duct C. Inferior Vena Cava D. Axillary Lymph node

Thoracic duct

What is the name of the condition where patients cannot absorb lipids becausethe lack of ability to form ApoB means chylomicrons can't be made?

Abetalipoproteinemia

What is the name of oily stool that can result if any problems arise in regard to pancreatic enzyme secretions, bile acid secretions, emulsification, micelle formation, diffusion of lipids into epithlieal cells, chylomicron formation, transfer of chylomicrons into the lymph?

Steatorrhea

What is the overlying theme for Panceratic insufficiency, ZES, Pancreatitis? A. Gastin secreting tumor of pancreas B. Impaired HCO3 and enzyme secretions C. Failure to secrete proper amounts of pancreatic enzymes D. Improper acidity of duodenum contents

Improper acidity of duodenum contents

Explain what causes Small Intestinal Bacterial Overgrowth (SIBO) to happen, so that SIBO leads to the bacteria deconjugating bile salts early and impairing miclle formation. *Hint 2 main causes* What substances do we look for in the breath to help diagnose SIBO?

1. Too little gastric secretion 2. Dysmotility of small intestine Detects: Methane and Hydrogen

Which of the following vitamins are mostly absorbed via Na-dependent cotransporter? (select all that apply) A. Vitamin B12 B. Vitamin C C. Vitamin A and Vitamin D D. Vitamin B1, B2, B6

Vitamin B1, B2, B6 Vitamin C * Fat soluble vitamins ADEK, are absorbed in a similar fashion as lipids* * Water soluble vitamins utilize the Na-dependent cotransporter EXCEPT for B12*

Which of the following vitamins is a maverick when it comes to vitamin absorption? A. Vitamin B12 B. Vitamin C C. Vitamin A and Vitamin D D. Vitamin B1, B2, B6

Vitamin B12 - R protein, IF, Transcobalamin II

In what location does B12 become bound to IF? A. Mouth B. Stomach C. Duodenum D. Jejunum E. Ileum

Duodenum

In what location is B12 exit the GI? A. Mouth B. Stomach C. Duodenum D. Jejunum E. Ileum

Ileum

Pernicious anemia is caused by failure of RBC maturation when vitamin B12 is deficient. Vitamin B12 is defiecient when the stomach does not produce enough IF. What are 2 common causes that lead to reduction in the amount of IF?

1. Atrophic gastritis: chronic inflammation of the stomach mucosa destroys parietal cells 2. Autoimmune Metaplastic Atrophic Gastritis: Immune system attacks IF protein or gastric parietal cells

In which of the following locations is iron absorbed? A. Stomach B. Duodenum C. Jejunum D. Ileum

Duodenum

In which of the following locations does the final starch breakdown occur via brush border enterocytes? A. Stomach B. Duodenum C. Jejunum D. Ileum

Jejunum

IRon binding occurs in the duodenum. ________ absorbs it from the gut, ________ transfers it to liver, spleen, or bone marrow where its stored in macrophages bound to \_\_\_\_\_\_\_.

IRon binding occurs in the duodenum. **Ferroportin** absorbs it from the gut, **Transferrin** transfers it to liver, spleen, or bone marrow where its stored in macrophages bound to **Ferritin**.

The small intestine and colon absorb large quantities of electrolytes and water, but epithelial cells lining the crypts also secrete fluid and electrolytes. The first step is absorption of solute THEN water, which happens in proportion to each other. What causes solute and water absorption to occur in proportion to each other? A. Absorbate is always hypertonic B. Absorbate is always hypotonic C. Absorbate is always isotonic D. None of the above

Absorbate is always isotonic

Which of the following accurately respresents the electrolyte absorption or secretion that occurs in the jejunum? A. Sodium absorption B. Sodium absorbed and HCO3 secreted C. Sodium absorbed, K+ secreted

Sodium absorption

Which of the following accurately respresents the electrolyte absorption or secretion that occurs in the ileum? A. Sodium absorption B. Sodium absorbed and HCO3 secreted C. Sodium absorbed, K+ secreted

Sodium absorbed and HCO3 secreted

Which of the following accurately respresents the electrolyte absorption or secretion that occurs in the colon? A. Sodium absorption B. Sodium absorbed and HCO3 secreted C. Sodium absorbed, K+ secreted

Sodium absorbed, K+ secreted

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Cool - increase cAMP increase Cl- secretion - sodium follows chloride, and water follows sodium HELLO MASsive Diarrhea