p.43
Absorption Mechanisms in the Small Intestine
Why is free iron considered toxic?
Because it can cause cellular damage.
p.23
Gallbladder Function and Gallstone Formation
What genetic factors contribute to the formation of gallstones?
Lithogenic genes promote the formation of calculi (stones).
p.57
Absorption Mechanisms in the Small Intestine
Which vitamins are fat-soluble and require micelles for absorption?
Vitamins A, D, E, and K2.
p.54
Enterohepatic Circulation
Where are bile salts absorbed in the digestive system?
Bile salts are absorbed in the distal ileum.
p.40
Absorption Mechanisms in the Small Intestine
What type of transport is involved in the absorption of calcium in the small intestine?
Secondary active transport.
p.48
Disorders of the Gastrointestinal Tract
What happens to lactose in individuals with lactose intolerance?
In individuals with lactose intolerance, undigested lactose serves as a substrate for bacteria in the colon.
p.40
Absorption Mechanisms in the Small Intestine
What role does the Transient Receptor Potential Vanilloid (TRPV) play in calcium absorption?
TRPV channels facilitate the entry of calcium into the cells of the small intestine.
p.65
Disorders of the Gastrointestinal Tract
What effect does the activation of parasympathetic nerves have on the internal anal sphincter?
It relaxes the sphincter via the release of VIP and nitric oxide.
p.57
Absorption Mechanisms in the Small Intestine
How is Vitamin K1, mostly from green vegetables, absorbed?
By an energy-dependent, carrier-mediated process.
p.83
Disorders of the Gastrointestinal Tract
What is a fecal transplant used to treat?
Chronic diarrhea, especially in elderly patients with antibiotic depletion.
p.24
Gallbladder Function and Gallstone Formation
What causes brown-colored gallstones?
A combination of cholesterol and bilirubin.
p.52
Pancreatic Enzyme Secretion and Activation
What is the role of colipase in fat digestion?
Colipase binds to lipase and anchors it to the fat droplets, allowing lipase to effectively break down fats.
p.52
Role of Bile in Digestion
How do bile salts aid in fat digestion?
Bile salts emulsify fats, breaking them down into smaller droplets, which increases the surface area for lipase action.
p.65
Disorders of the Gastrointestinal Tract
What effect does the activation of sympathetic nerves have on the internal anal sphincter?
It contracts the sphincter.
p.32
Absorption Mechanisms in the Small Intestine
What is the role of peristalsis in the small intestine?
To move the contents through the digestive tract.
p.32
Absorption Mechanisms in the Small Intestine
How often does segmentation occur in the proximal small intestine?
Approximately 12 times per minute.
p.59
Absorption Mechanisms in the Small Intestine
Do migrating motor complexes occur during feeding?
No, migrating motor complexes do not occur during feeding.
p.43
Absorption Mechanisms in the Small Intestine
How does Fe2+ enter the enterocyte?
Via DMT1 (in association with H+).
p.72
Disorders of the Gastrointestinal Tract
What is the mechanism behind secretory (infectious) diarrhea?
Bacterial infections of the crypts of the small and large intestines stimulate cAMP to increase Cl- transport across the intestinal wall, followed by Na+ and water, producing diarrhea.
p.8
Regulation of Pancreatic Secretions
What triggers an increase in pancreatic enzyme secretion?
Stimulation of M3 and CCK A receptors.
p.27
Exocrine and Endocrine Functions of the Pancreas
What is the role of CCK in the digestive system?
CCK stimulates the secretion of pancreatic enzymes.
p.53
Role of Bile in Digestion
What is a micelle?
A micelle is an aggregate of molecules in a colloidal solution, such as those formed by detergents.
p.83
Disorders of the Gastrointestinal Tract
What is SER-109?
A pill used for fecal transplants that contains freeze-dried stool from healthy subjects.
p.50
Pancreatic Enzyme Secretion and Activation
What role does carboxypolypeptidase play in protein digestion?
Carboxypolypeptidase, produced by the pancreas, breaks down peptides into individual amino acids in the small intestine.
p.59
Disorders of the Gastrointestinal Tract
What symptoms are associated with the medical student's IBS?
Fluctuating constipation and diarrhea.
p.82
Disorders of the Gastrointestinal Tract
How does the misfolding of alpha-synuclein reach the brain in Parkinson's Disease?
The misfolded alpha-synuclein can travel via the vagus nerve to the brain.
p.25
Gallbladder Function and Gallstone Formation
What are the common components of gallstones?
Gallstones are commonly composed of cholesterol or bilirubin.
p.18
Enterohepatic Circulation
How often does the bile salt pool recycle in a day?
The bile salt pool recycles about 6 - 8 times per day.
p.18
Enterohepatic Circulation
What determines the rate of bile salt synthesis in the liver?
The rate of bile salt synthesis is determined by the rate of return to the liver.
p.73
Disorders of the Gastrointestinal Tract
What defines chronic constipation?
When symptoms persist for at least 3 months.
p.45
Absorption Mechanisms in the Small Intestine
Where does the digestion of carbohydrates begin?
In the mouth with the enzyme amylase.
p.29
Pancreatic Anatomy and Functions
What is the function of the myenteric plexus (Auerbach’s plexus) in the small intestine?
It controls gastrointestinal motility.
p.83
Disorders of the Gastrointestinal Tract
What phase are the clinical trials for SER-109 currently in?
Phase III clinical trials.
p.83
Disorders of the Gastrointestinal Tract
What is the main component of the SER-109 pill?
Freeze-dried stool from healthy subjects.
p.48
Disorders of the Gastrointestinal Tract
What is lactose intolerance?
Lactose intolerance is the inability to digest lactose, a sugar found in milk and dairy products, due to a deficiency in the enzyme lactase.
p.59
Disorders of the Gastrointestinal Tract
What condition does the 25-year-old medical student have that affects her intestinal motility?
Irritable bowel syndrome (IBS).
p.56
Pancreatic Enzyme Secretion and Activation
Which enzymes work together to further digest fats in the small intestine?
Pancreatic lipase and colipase.
p.59
Absorption Mechanisms in the Small Intestine
Which statement about small intestinal motility is correct?
Contractile activity is initiated in response to distention.
p.41
Absorption Mechanisms in the Small Intestine
What happens to senescent erythrocytes in the body?
They are processed by the reticuloendothelial system.
p.45
Absorption Mechanisms in the Small Intestine
What are the main macronutrients involved in digestion and absorption?
Carbohydrates (CHO), fats, and proteins.
p.18
Enterohepatic Circulation
What percentage of bile salts are reabsorbed in the enterohepatic circulation?
95% of bile salts are reabsorbed in the enterohepatic circulation.
p.77
Disorders of the Gastrointestinal Tract
Which parts of the gut are typically affected by Crohn's disease?
Typically, the distal ileum or colon, although any region of the gut (small and large intestine) can be involved.
p.51
Role of Bile in Digestion
What happens to fatty acids and monoglycerides after they are formed by pancreatic lipase?
They retain association with bile salts to form micelles.
p.55
Absorption Mechanisms in the Small Intestine
What are the main components of chylomicrons?
Chylomicrons are composed of triglycerides (90%), phospholipids (7%), cholesterol (2%), and proteins (1%).
p.34
Pancreatic Anatomy and Functions
What are the two main muscle layers in the small intestine?
Longitudinal muscle and circular muscle.
p.29
Pancreatic Anatomy and Functions
What is the role of the muscularis mucosae in the small intestine?
It helps in the movement of the mucosa.
p.76
Disorders of the Gastrointestinal Tract
What is diverticulosis?
Herniation of the mucosa and submucosa through the muscularis propria.
p.53
Role of Bile in Digestion
What are the key components involved in micelle formation?
Cholesterol, lecithins, monoglycerides, and free fatty acids.
p.58
Disorders of the Gastrointestinal Tract
What is the primary difference between normal small intestine villi and those affected by Sprue?
Normal villi are healthy and aid in absorption, while villi affected by Sprue are stunted or inflamed, reducing the surface area for absorption.
p.53
Role of Bile in Digestion
What is the role of free fatty acids in micelle formation?
Free fatty acids, released from triglycerides, are incorporated into micelles to aid in their transport and absorption.
p.52
Role of Bile in Digestion
What is the interaction between lipids and bile salts?
Lipids and bile salts have similar charges, causing them to repel one another and preventing the reformation of large fat droplets.
p.65
Disorders of the Gastrointestinal Tract
What neurotransmitters are involved in the relaxation of the internal anal sphincter?
VIP (vasoactive intestinal peptide) and nitric oxide.
p.25
Gallbladder Function and Gallstone Formation
What are gallstones?
Hardened deposits that form in the gallbladder, often composed of cholesterol or bilirubin.
p.49
Absorption Mechanisms in the Small Intestine
What provides the energy for the sodium co-transport system used in glucose and galactose absorption?
Energy derived from sodium-potassium ATPase (Secondary Active Transport).
p.51
Role of Bile in Digestion
What are the two domains of bile salts?
Hydrophilic and hydrophobic domains.
p.29
Pancreatic Anatomy and Functions
What are the two main muscle layers in the small intestine?
Longitudinal muscle and circular muscle.
p.13
Liver Functions and Blood Flow
What is one of the primary functions of the liver related to nutrients?
Metabolic processing of absorbed nutrients.
p.62
Absorption Mechanisms in the Small Intestine
Does nutrient absorption take place in the colon?
No, nutrient absorption does not take place in the colon.
p.45
Absorption Mechanisms in the Small Intestine
Where does the digestion of fats primarily occur?
In the small intestine with the help of bile and pancreatic lipase.
p.55
Absorption Mechanisms in the Small Intestine
What role do fatty acid-binding proteins (FABP) play in chylomicron formation?
FABPs transport fatty acids within the cell to the smooth endoplasmic reticulum for chylomicron assembly.
p.54
Enterohepatic Circulation
What happens to bile salts during lipid absorption?
Bile salts are removed and recycled via the enterohepatic circulation.
p.40
Absorption Mechanisms in the Small Intestine
What does PCMA stand for in the context of calcium absorption?
PCMA stands for Plasma Membrane Calcium ATPase.
p.76
Disorders of the Gastrointestinal Tract
What is diverticulitis?
A condition where the mucosa in a diverticulum is perforated, often related to entrapped food.
p.58
Disorders of the Gastrointestinal Tract
What is Tropical Sprue?
It is a condition characterized by inflammation of the villi, potentially caused by bacterial, viral, or parasitic infections.
p.83
Disorders of the Gastrointestinal Tract
What are some concerns associated with fecal transplant treatments?
Concerns include companies collecting stools facing financial trouble, donor availability, cost of treatment, and the potency of the pill versus fresh fecal material.
p.61
Pancreatic Anatomy and Functions
What are the two main sides of the colon?
The colon has a right side and a left side.
p.49
Absorption Mechanisms in the Small Intestine
How are glucose and galactose absorbed in the small intestine?
Via a sodium co-transport system (SGLT1; secondary active transport).
p.31
Disorders of the Gastrointestinal Tract
How often do slow waves occur in the gastrointestinal tract?
10 - 20 times per minute.
p.51
Pancreatic Enzyme Secretion and Activation
What must triglycerides be digested into for fat digestion?
Monoglycerides and fatty acids.
p.51
Role of Bile in Digestion
How do bile salts aid in the emulsification of fats?
The hydrophobic portions intercalate into the lipid, while the hydrophilic domains remain on the surface, aiding in emulsification.
p.51
Pancreatic Enzyme Secretion and Activation
How does pancreatic lipase function in fat digestion?
Pancreatic lipase splits fats into fatty acids and monoglycerides.
p.72
Disorders of the Gastrointestinal Tract
How can secretory diarrhea be treated?
Using glucose and sodium.
p.41
Absorption Mechanisms in the Small Intestine
What is the role of heme in iron absorption?
Heme iron, found in hemoglobin (Hb), is more easily absorbed by the body.
When is the gut microbiota established in humans?
At birth, from the mother's vaginal microbes.
p.54
Absorption Mechanisms in the Small Intestine
What is the role of micelles in lipid absorption?
Micelles stabilize lipids and help them cross the unstirred layer and the lipid membrane barrier.
p.58
Disorders of the Gastrointestinal Tract
What causes the adverse mucosal response in Celiac Disease?
Gluten found in wheat or rye-based foods.
p.76
Disorders of the Gastrointestinal Tract
How is diet related to diverticular disease?
It is decreased in those with high fiber diets.
p.50
Pancreatic Enzyme Secretion and Activation
Where is trypsin produced and what is its function in protein digestion?
Trypsin is produced in the pancreas and it further breaks down peptides into smaller peptides and amino acids in the small intestine.
p.48
Disorders of the Gastrointestinal Tract
What is a common byproduct of bacterial fermentation of lactose in the colon?
A common byproduct is gas, particularly hydrogen.
p.82
Disorders of the Gastrointestinal Tract
How can the gut microbiome influence Autism Spectrum Disorder (ASD)?
Bacteria in the mother's gut can affect T-helper cells, which in turn can influence the development of Autism Spectrum Disorder (ASD) through the release of cytokines.
p.82
Disorders of the Gastrointestinal Tract
What are cytokines and how are they related to Autism Spectrum Disorder?
Cytokines are signaling proteins released by T-helper cells that can influence the development of Autism Spectrum Disorder.
p.26
Liver Functions and Blood Flow
Why might bilirubin not be found in the urine of a jaundiced patient?
Because the bilirubin has not been conjugated by UDP - GT and thus cannot be excreted in the urine.
p.41
Absorption Mechanisms in the Small Intestine
What role does plasma transferrin play in iron metabolism?
It transports iron in the blood.
p.28
Pancreatic Enzyme Secretion and Activation
What is the most likely primary cause of the patient's apparent fat malabsorption?
Diminished secretion of pancreatic lipase.
p.55
Absorption Mechanisms in the Small Intestine
Where are chylomicrons assembled in the cell?
Chylomicrons are assembled in the smooth endoplasmic reticulum (ER) of enterocytes.
p.78
Disorders of the Gastrointestinal Tract
What is Inflammatory Bowel Disease (IBD)?
IBD is a term used to describe disorders that involve chronic inflammation of the digestive tract, including Crohn's disease and ulcerative colitis.
p.29
Pancreatic Anatomy and Functions
What is the mucosa layer in the small intestine responsible for?
It is responsible for absorption and secretion.
p.8
Regulation of Pancreatic Secretions
What is the role of CCK A receptors in pancreatic enzyme secretion?
CCK A receptors play a major role in stimulating enzyme secretion, with minimal effect on ductal cells.
p.58
Disorders of the Gastrointestinal Tract
What is another name for Celiac Disease?
Gluten Enteropathy or Sprue.
p.50
Pancreatic Enzyme Secretion and Activation
What is the function of chymotrypsin in protein digestion?
Chymotrypsin, produced by the pancreas, breaks down proteins into smaller peptides in the small intestine.
p.84
Disorders of the Gastrointestinal Tract
What is the impact of a 1% increase in the adenoma detection rate on the risk of colon cancer?
For every 1% increase in the adenoma detection rate, there is a 3% decrease in the risk of colon cancer developing within 5 years of a colonoscopy.
p.32
Absorption Mechanisms in the Small Intestine
What is the primary function of segmentation in the small intestine?
To increase the surface area for nutrient absorption.
p.18
Enterohepatic Circulation
What is the circulating pool of bile salts in the body?
The circulating pool of bile salts (primary and secondary) is 3 - 4 grams.
p.31
Disorders of the Gastrointestinal Tract
What triggers weak contractions in the gastrointestinal tract?
Stretching of the GI tract.
p.25
Gallbladder Function and Gallstone Formation
How do gallstones form in the gallbladder?
Gallstones form when substances in the bile, such as cholesterol or bilirubin, harden into solid particles.
p.72
Disorders of the Gastrointestinal Tract
What is a common cause of osmotic diarrhea?
Deficiency in the absorption of products of digestion in the small intestine, such as in lactose intolerance.
p.32
Absorption Mechanisms in the Small Intestine
What does ICC stand for in the context of small intestine motility?
Interstitial Cells of Cajal.
p.37
Absorption Mechanisms in the Small Intestine
What type of junctions does the small intestine have and what is their significance?
The small intestine has 'leaky' junctions (0.8 nm) which allow for 80 - 90% absorption of water.
p.37
Absorption Mechanisms in the Small Intestine
How does the osmolality of a meal compare to blood plasma?
A meal is usually hypertonic to plasma, with a meal having 600 mOSM and blood having 300 mOSM.
p.37
Absorption Mechanisms in the Small Intestine
What causes the reabsorption of water in the small intestine?
The osmotic gradient set by the movement of solutes causes reabsorption of water.
p.45
Absorption Mechanisms in the Small Intestine
Where does the digestion of proteins begin?
In the stomach with the enzyme pepsin.
p.28
Disorders of the Gastrointestinal Tract
What are the characteristics of stools in fat malabsorption?
Pale, bulky, and foul-smelling.
p.74
Disorders of the Gastrointestinal Tract
What are the primary symptoms of Hirschsprung's Disease?
The primary symptoms include severe constipation, abdominal distension, and failure to pass meconium shortly after birth.
p.78
Disorders of the Gastrointestinal Tract
What characterizes Crohn's disease?
Crohn's disease is characterized by inflammation that can occur anywhere along the digestive tract, often spreading deep into affected tissues.
p.20
Gallbladder Function and Gallstone Formation
What triggers the release of bile from the gallbladder?
The release of bile is triggered by the hormone cholecystokinin (CCK), which stimulates the contraction of the gallbladder.
p.23
Gallbladder Function and Gallstone Formation
What hepatic factor contributes to gallstone formation?
Hypersecretion of cholesterol.
p.47
Pancreatic Enzyme Secretion and Activation
What is the role of isomaltase in carbohydrate digestion?
Isomaltase breaks down isomaltose into glucose molecules.
What type of relationship does the gut microbiota form with its host?
A symbiotic relationship that influences host health.
p.40
Absorption Mechanisms in the Small Intestine
What is the primary mechanism for calcium absorption in the small intestine?
Secondary active transport.
p.58
Disorders of the Gastrointestinal Tract
What happens to the villi in Celiac Disease?
There is stunting of villi and a decrease in the surface area for absorption.
p.53
Role of Bile in Digestion
What are lecithins and their role in micelle formation?
Lecithins are a type of phospholipid that help emulsify fats, aiding in micelle formation.
p.25
Gallbladder Function and Gallstone Formation
What is gallstone jewelry?
Jewelry made from gallstones, which are hardened deposits that form in the gallbladder.
p.59
Disorders of the Gastrointestinal Tract
What has caused the medical student's IBS to worsen recently?
The approaching date of STEP 1.
p.49
Absorption Mechanisms in the Small Intestine
How is fructose transported in the small intestine?
Via carrier-mediated facilitated diffusion (GLUT5; passive transport).
p.72
Disorders of the Gastrointestinal Tract
What characterizes diarrhea?
An increase in frequency and a decrease in consistency of fecal discharge from what is normal for that individual.
p.62
Disorders of the Gastrointestinal Tract
What is the role of the colon in the movement of fecal material?
It moves fecal material towards the rectum.
p.62
Disorders of the Gastrointestinal Tract
Are there any digestive enzymes in the colon?
No, there are no digestive enzymes in the colon.
p.55
Absorption Mechanisms in the Small Intestine
What is the primary role of chylomicrons in the body?
Chylomicrons transport dietary lipids from the intestines to other locations in the body.
p.13
Liver Functions and Blood Flow
How does the liver detoxify and degrade body wastes and xenobiotics?
By making them water soluble through Phase I and Phase II reactions.
p.45
Role of Bile in Digestion
What role does bile play in fat digestion?
Bile emulsifies fats, breaking them into smaller droplets for easier digestion by enzymes.
p.34
Pancreatic Anatomy and Functions
What is the function of the muscularis mucosae in the small intestine?
The muscularis mucosae helps in the movement of the mucosa to enhance contact with digestive contents.
p.55
Absorption Mechanisms in the Small Intestine
What is the pathway for triglyceride synthesis in chylomicron formation?
Fatty acids and monoacylglycerides are converted to diacylglycerides (DG) and then to triglycerides (TG) in the smooth ER.
p.20
Gallbladder Function and Gallstone Formation
How is bile stored in the gallbladder?
Bile is stored in a concentrated form, 5 to 15 times more concentrated than its original form, in the gallbladder.
p.45
Absorption Mechanisms in the Small Intestine
How are amino acids absorbed in the small intestine?
Through active transport mechanisms.
p.34
Pancreatic Anatomy and Functions
What is the role of the myenteric plexus (Auerbach’s plexus) in the small intestine?
The myenteric plexus (Auerbach’s plexus) controls gastrointestinal motility.
p.69
Absorption Mechanisms in the Small Intestine
What happens to H2CO3 in the colonocytes?
H2CO3 dissociates into H+ and HCO3- (bicarbonate).
p.69
Absorption Mechanisms in the Small Intestine
How is chloride (Cl-) absorbed in the colon?
Chloride is absorbed in exchange for bicarbonate (HCO3-) secretion.
p.47
Pancreatic Enzyme Secretion and Activation
Where is isomaltase located in the digestive system?
Isomaltase is located in the brush border of the small intestine.
p.9
Regulation of Pancreatic Secretions
What role do peptides and amino acids play in the gastric phase of pancreatic secretion?
They help trigger the release of gastrin.
p.9
Regulation of Pancreatic Secretions
What is the effect of gastrin release during the gastric phase of pancreatic secretion?
It stimulates the acini cells (minor effect) but does not stimulate the ducts.
p.27
Exocrine and Endocrine Functions of the Pancreas
Which of the following is true regarding the secretions from an exocrine pancreas?
D. pancreatic enzyme secretion is increased by CCK.
p.53
Role of Bile in Digestion
What role does cholesterol play in micelle formation?
Cholesterol helps stabilize the micelle structure.
p.53
Role of Bile in Digestion
How do monoglycerides contribute to micelle formation?
Monoglycerides, which are products of fat digestion, help in the emulsification and absorption of lipids by forming micelles.
p.50
Pancreatic Enzyme Secretion and Activation
What is the role of pepsin in protein digestion?
Pepsin breaks down proteins into smaller peptides in the stomach.
p.82
Disorders of the Gastrointestinal Tract
What is the relationship between the gut microbiome and Parkinson's Disease?
Protein misfolding in E. coli, specifically curli proteins, can influence the misfolding of alpha-synuclein, which is associated with Parkinson's Disease. This misfolding can travel via the vagus nerve to the brain.
p.84
Disorders of the Gastrointestinal Tract
Where is GI Genius currently being used?
GI Genius is currently being used at Northwestern University.
p.56
Absorption Mechanisms in the Small Intestine
What structures are formed to transport digested fats through the intestinal wall?
Micelles and chylomicrons.
p.18
Enterohepatic Circulation
How much bile salt is needed to digest a meal?
4 - 8 grams of bile salts are needed to digest a meal.
p.73
Disorders of the Gastrointestinal Tract
What are common symptoms of constipation?
Difficulty or lack of urge to defecate, fewer than 3 stools/week for women and 5 for men despite proper diet, period greater than three days between stools, straining more than 25% of the time with 2 or fewer stools per week.
p.72
Disorders of the Gastrointestinal Tract
Which bacteria are commonly associated with secretory diarrhea?
E. coli and cholera toxin.
p.43
Absorption Mechanisms in the Small Intestine
What happens if plasma transferrin is saturated?
It inhibits basolateral transport and uptake of iron.
p.74
Disorders of the Gastrointestinal Tract
What is Hirschsprung's Disease?
Hirschsprung's Disease is a congenital condition where nerve cells are missing in parts of the muscles of the colon, causing severe constipation or intestinal obstruction.
p.38
Absorption Mechanisms in the Small Intestine
Where is sodium absorbed in the intestines?
90% of sodium is absorbed in the small intestine and 10% in the large intestine.
p.55
Absorption Mechanisms in the Small Intestine
What happens to chylomicrons after they are assembled in the enterocytes?
Chylomicrons are secreted into the lymphatic system and then enter the bloodstream.
p.55
Absorption Mechanisms in the Small Intestine
What types of lipids do chylomicrons primarily transport?
Chylomicrons primarily transport triglycerides, but also carry cholesterol and phospholipids.
p.9
Regulation of Pancreatic Secretions
What triggers the cephalic phase of pancreatic secretion?
Central nervous system via the vagus nerve.
p.14
Liver Functions and Blood Flow
What are the two sources of blood flow to the liver?
Portal vein (75%) and hepatic artery (25%).
p.14
Liver Functions and Blood Flow
What is the 'First Pass Effect' in drug absorption?
All substances absorbed in the gut must pass through the liver before entering systemic circulation.
p.75
Disorders of the Gastrointestinal Tract
What are the main symptoms of Irritable Bowel Syndrome (IBS)?
Altered bowel habits and abdominal pain in the absence of detectable structural abnormalities.
p.10
Regulation of Pancreatic Secretions
What is the role of secretin in pancreatic secretion?
Secretin increases the secretion of bicarbonate and fluid from ductal cells.
p.20
Gallbladder Function and Gallstone Formation
How does the secretion of H+ ions affect bile in the gallbladder?
The secretion of H+ ions neutralizes HCO3- and acidifies the bile.
p.46
Absorption Mechanisms in the Small Intestine
What are the main sources of dietary carbohydrates?
Polysaccharides, disaccharides, and monosaccharides.
p.24
Gallbladder Function and Gallstone Formation
What causes black-colored gallstones?
Too much bilirubin, often seen in individuals with cirrhosis of the liver or hereditary blood disorders like sickle cell anemia (SCA).
p.61
Pancreatic Anatomy and Functions
What is the general shape of the colon?
The colon is flat and ribbon-like.
p.36
Absorption Mechanisms in the Small Intestine
What is the mechanism of water movement in the GI tract?
Water movement is passive and relies on the movement of ions/substrate.
p.84
Disorders of the Gastrointestinal Tract
What is GI Genius?
GI Genius is a computer-aided polyp detection system.
p.52
Role of Bile in Digestion
Why is it important that bile salts prevent the reformation of large fats?
Preventing the reformation of large fats ensures that fats remain in smaller droplets, which are more accessible to digestive enzymes like lipase.
p.49
Absorption Mechanisms in the Small Intestine
What type of transport is used for basolateral transport of carbohydrates?
Facilitated diffusion (GLUT2).
p.51
Pancreatic Enzyme Secretion and Activation
What is the role of colipase in fat digestion?
Colipase displaces bile salts from fat to aid pancreatic lipase in the digestion of fats and serves as a receptor for pancreatic lipase.
p.73
Disorders of the Gastrointestinal Tract
What are some common causes of constipation?
Diet-induced, drugs, stress, overuse of laxatives, constant suppression of urge to defecate (Gastrocolic reflex).
p.43
Absorption Mechanisms in the Small Intestine
What limits the uptake of iron at the apical membrane?
Mobilferrin, which binds iron.
p.37
Absorption Mechanisms in the Small Intestine
What occurs as the meal traverses the small intestine?
Ions and solutes are absorbed, decreasing the osmolality of the meal.
p.28
Pancreatic Enzyme Secretion and Activation
What role does pancreatic lipase play in digestion?
Pancreatic lipase breaks down dietary fats into fatty acids and glycerol, which are then absorbed by the intestines.
p.78
Disorders of the Gastrointestinal Tract
What are the two main types of Inflammatory Bowel Disease?
The two main types are Crohn's disease and ulcerative colitis.
p.13
Liver Functions and Blood Flow
What substances does the liver store?
Iron, fats, vitamins (B12), and glycogen.
p.35
Absorption Mechanisms in the Small Intestine
What is the brush border in the small intestine?
The brush border is a layer of microvilli on the surface of enterocytes that increases the surface area for absorption.
p.74
Disorders of the Gastrointestinal Tract
What is the main treatment for Hirschsprung's Disease?
The main treatment is surgical removal of the affected portion of the colon, known as a pull-through procedure.
p.23
Gallbladder Function and Gallstone Formation
What intestinal factor contributes to gallstone formation?
Increased cholesterol absorption.
p.2
Pancreatic Enzyme Secretion and Activation
Why are pancreatic secretions isotonic at all rates of secretion?
Because ductal cells are permeable to water, maintaining the secretion as isotonic.
What are TMA and TMAO, and what are they associated with?
Trimethylamine (TMA) and trimethylamine oxide (TMAO) are compounds associated with atherosclerosis, heart disease, and stroke.
p.4
Regulation of Pancreatic Secretions
What happens to the proteolytic enzymes when CFTR is lost?
The proteolytic enzymes remain active.
p.20
Gallbladder Function and Gallstone Formation
Why is the acidification of bile important?
Acidification increases the solubility of calcium salts in bile, reducing the chance of gallstone formation.
p.46
Absorption Mechanisms in the Small Intestine
What is starch and where is it commonly found?
Starch is a major plant storage form of glucose, commonly found in corn, grains, bananas, cereal, rice, wheat, and potatoes.
p.67
Absorption Mechanisms in the Small Intestine
To what concentration can colonic Na+ transport continue and why?
Colonic Na+ transport can continue until the luminal concentration is 30 mM because there is no 'backwash' of Na+ from interstitial fluid to the lumen of the colon.
p.39
Absorption Mechanisms in the Small Intestine
How does passive paracellular diffusion of calcium occur in the small intestine?
It occurs throughout the small intestine but is not adequate for all calcium absorption.
p.19
Absorption Mechanisms in the Small Intestine
How does fiber lower serum cholesterol?
Fiber binds bile acids and salts, which helps to lower serum cholesterol.
p.2
Pancreatic Enzyme Secretion and Activation
How does the concentration of HCO3- in pancreatic secretions change with flow rate?
The concentration of HCO3- increases as the flow rate increases.
p.61
Pancreatic Anatomy and Functions
How is the outer longitudinal muscle of the colon structured?
The outer longitudinal muscle of the colon is not continuous and is divided into three bands.
p.84
Disorders of the Gastrointestinal Tract
How much more effective is GI Genius in detecting and removing adenomas?
GI Genius is able to detect and remove 13% more adenomas.
p.49
Absorption Mechanisms in the Small Intestine
Where is the highest capacity for carbohydrate absorption in the small intestine?
In the duodenum and upper jejunum.
p.82
Disorders of the Gastrointestinal Tract
What role do curli proteins play in Parkinson's Disease?
Curli proteins in E. coli can cause the misfolding of alpha-synuclein, which is linked to Parkinson's Disease.
p.62
Disorders of the Gastrointestinal Tract
What is one of the primary functions of the colon?
Storage of fecal material.
p.26
Liver Functions and Blood Flow
What condition is indicated by mild jaundice without bilirubin in the urine?
A delay in the expression or establishment of UDP - GT.
p.59
Absorption Mechanisms in the Small Intestine
What type of contractile activity occurs during feeding in the small intestine?
Peristalsis is one of the contractile activities that occurs during feeding.
p.72
Disorders of the Gastrointestinal Tract
What triggers psychogenic diarrhea?
Stressful events, likely related to activation of the parasympathetic nervous system.
p.37
Absorption Mechanisms in the Small Intestine
What is the absorptive capability of the small intestine?
About 15 - 20 liters/day.
p.73
Disorders of the Gastrointestinal Tract
What is Hirschsprung’s Disease?
A congenital megacolon condition characterized by the absence of the myenteric plexus in the colon, leading to areas of contraction and constipation.
p.77
Disorders of the Gastrointestinal Tract
What is a key characteristic of ulcerative colitis?
Inflammation of the colon with rectal bleeding.
p.45
Absorption Mechanisms in the Small Intestine
How are fatty acids and monoglycerides absorbed in the small intestine?
They are absorbed into the intestinal cells and then reassembled into triglycerides.
p.43
Absorption Mechanisms in the Small Intestine
Where is iron stored and utilized in the body?
Iron is stored in the liver and utilized in the bone marrow.
p.35
Absorption Mechanisms in the Small Intestine
What is the primary function of enterocytes in the small intestine?
Enterocytes are responsible for absorption and secretion in the small intestine.
p.47
Pancreatic Enzyme Secretion and Activation
Where is amylase produced in the body?
Amylase is produced in the salivary glands and the pancreas.
p.55
Absorption Mechanisms in the Small Intestine
What happens to short-chain fatty acids and glycerol during lipid absorption?
Short-chain fatty acids and glycerol are absorbed directly into the bloodstream, bypassing chylomicron formation.
p.19
Absorption Mechanisms in the Small Intestine
What are some health benefits of a high fiber diet?
High fiber diets prevent/relieve constipation, hemorrhoids, inflammatory diseases of the colon, colon cancer, and rectal cancer.
p.78
Disorders of the Gastrointestinal Tract
What is severe colitis?
Severe colitis is a more intense inflammation of the colon, which can cause severe abdominal pain, frequent diarrhea, and significant weight loss.
p.19
Absorption Mechanisms in the Small Intestine
How does a high fiber diet affect feces?
It has mechanical and chemical effects on feces, including an osmotic effect.
p.67
Absorption Mechanisms in the Small Intestine
How do tight junctions in the colon affect the movement of molecules?
Tight junctions in the colon have much higher resistance to the movement of molecules.
p.75
Disorders of the Gastrointestinal Tract
What might be a cause of altered sensory afferents in IBS patients?
It may be related to post-infection.
What are probiotics and how do they benefit the host?
Probiotics are live microorganisms that interact with the microbiota to benefit the host, often found in foods like yogurt, sauerkraut, tempeh, and kimchi.
p.75
Disorders of the Gastrointestinal Tract
When do IBS symptoms typically appear?
During wake hours, usually fine at night (sleep).
p.21
Disorders of the Gastrointestinal Tract
What causes the yellowing of the skin and sclera in jaundice?
Excess production or loss of metabolism of bilirubin or biliverdin.
p.46
Absorption Mechanisms in the Small Intestine
What are the three main disaccharides?
Sucrose, maltose, and lactose.
p.6
Pancreatic Enzyme Secretion and Activation
What does phospholipase A2 do?
Phospholipase A2 splits phospholipids into fatty acids.
p.48
Disorders of the Gastrointestinal Tract
What are the symptoms of lactose intolerance?
Symptoms include bloating, gas, diarrhea, and abdominal pain after consuming lactose-containing foods.
p.26
Liver Functions and Blood Flow
What enzyme is responsible for conjugating bilirubin in the liver?
UDP - GT (Uridine diphosphate glucuronosyltransferase).
p.59
Regulation of Pancreatic Secretions
What is the effect of vagotomy on contractile activity during the digestive period?
Vagotomy abolishes contractile activity during the digestive period.
p.72
Disorders of the Gastrointestinal Tract
What causes inflammatory (exudative) diarrhea?
A decrease in surface area for reabsorption of water and electrolytes, related to inflammation of the mucosa of the small and large intestines.
p.28
Disorders of the Gastrointestinal Tract
What symptoms is the 4-year-old boy experiencing?
Failure to thrive and frequent diarrhea characterized by pale, bulky, foul-smelling stools.
p.77
Disorders of the Gastrointestinal Tract
What characterizes Crohn's disease?
Ulcerations and inflammation involving the entire thickness of the gut wall.
p.45
Absorption Mechanisms in the Small Intestine
How are monosaccharides absorbed in the small intestine?
Through active transport and facilitated diffusion.
p.77
Disorders of the Gastrointestinal Tract
How does the extent of involvement in ulcerative colitis differ from Crohn's disease?
Ulcerative colitis can involve the entire length of the colon, unlike Crohn's disease.
p.34
Pancreatic Anatomy and Functions
What is the mucosa layer in the small intestine responsible for?
The mucosa layer is responsible for absorption and secretion.
p.47
Pancreatic Enzyme Secretion and Activation
What is the primary function of amylase in carbohydrate digestion?
Amylase breaks down starches into simpler sugars like maltose and dextrins.
p.37
Absorption Mechanisms in the Small Intestine
What type of junctions does the large intestine have and what is their significance?
The large intestine has very tight junctions (0.23 nm) between epithelial cells.
p.70
Absorption Mechanisms in the Small Intestine
What is the normal state of potassium (K+) in the colon?
The normal state is absorption of potassium.
p.78
Disorders of the Gastrointestinal Tract
What is mild colitis?
Mild colitis refers to a less severe form of inflammation in the colon, often with symptoms like mild abdominal pain and diarrhea.
p.38
Absorption Mechanisms in the Small Intestine
What are the four mechanisms for sodium absorption?
1. Na/Glu and Na/AA co-transporter, 2. Na/H Exchanger, 3. Na/H and Cl/HCO3 Exchanger, 4. Epithelial sodium channels.
p.67
Absorption Mechanisms in the Small Intestine
What substances does the mammalian large intestine secrete?
The mammalian large intestine secretes potassium and bicarbonate.
p.9
Regulation of Pancreatic Secretions
What triggers the gastric phase of pancreatic secretion?
Distention of the stomach and peptides/amino acids.
What are some functions of the gut microbiota?
Regulates metabolism of nutrients, protects against pathogens, signals the immune system, and communicates with many organ systems.
p.19
Absorption Mechanisms in the Small Intestine
What is the osmotic effect of fiber in the colon?
The osmotic effect of fiber draws water into the colon, which helps to soften the stool and promote bowel movements.
p.2
Pancreatic Enzyme Secretion and Activation
Why is it important for pancreatic enzymes to work at a higher pH?
Because pancreatic enzymes work best at higher pH levels.
p.9
Regulation of Pancreatic Secretions
What is the volume of secretion during the gastric phase of pancreatic secretion?
Small volume of secretion.
p.21
Disorders of the Gastrointestinal Tract
What is hepatic jaundice and what conditions are associated with it?
Hepatic jaundice occurs when the liver cannot process a normal amount of bilirubin, often seen in liver diseases such as cirrhosis, hepatitis, and alcohol-related liver disease.
p.4
Regulation of Pancreatic Secretions
What is the effect of CFTR on water movement in the ducts?
Loss of CFTR results in less water movement to the duct.
p.25
Gallbladder Function and Gallstone Formation
Why might someone create jewelry from gallstones?
Gallstone jewelry can be a unique and personal keepsake, often created for sentimental or artistic reasons.
p.82
Disorders of the Gastrointestinal Tract
What immune cells are involved in the gut microbiome's influence on Autism Spectrum Disorder?
T-helper cells are involved in the gut microbiome's influence on Autism Spectrum Disorder.
p.41
Absorption Mechanisms in the Small Intestine
What is the primary goal of iron absorption in the small intestine?
To replace the 2mg daily loss of iron.
p.32
Absorption Mechanisms in the Small Intestine
How often does segmentation occur in the distal small intestine?
Approximately 8 times per minute.
p.59
Absorption Mechanisms in the Small Intestine
Is the contractile frequency constant from the duodenum to the terminal ileum?
No, the contractile frequency is not constant from the duodenum to the terminal ileum.
p.77
Disorders of the Gastrointestinal Tract
What are the consequences of the thickening of the intestinal mucosa in Crohn's disease?
Malabsorption and diarrhea.
p.77
Disorders of the Gastrointestinal Tract
What can happen even after surgery to remove a diseased segment in Crohn's disease?
The disease can re-occur at other areas.
p.38
Absorption Mechanisms in the Small Intestine
How much sodium is secreted and ingested daily?
20-30 grams of sodium are secreted daily, but only 2-5 grams are ingested.
p.69
Absorption Mechanisms in the Small Intestine
What is the role of bicarbonate secretion in the colon?
Bicarbonate secretion in the colon helps neutralize acid produced by bacteria.
p.70
Absorption Mechanisms in the Small Intestine
What happens to potassium (K+) in the colon when plasma K+ is less than 15 mEq/L?
Potassium is secreted into the lumen.
p.23
Gallbladder Function and Gallstone Formation
Which population has a high incidence of gallstones?
Native American population.
p.1
Exocrine and Endocrine Functions of the Pancreas
What is the endocrine function of the pancreas?
Secretion of insulin and glucagon by the Islets of Langerhans.
p.9
Regulation of Pancreatic Secretions
What is the volume of secretion during the cephalic phase of pancreatic secretion?
Small volume of secretion.
p.2
Pancreatic Enzyme Secretion and Activation
How does the flow rate of pancreatic secretions compare to plasma?
Pancreatic secretions are isotonic to plasma at all rates of secretion.
p.74
Disorders of the Gastrointestinal Tract
What causes Hirschsprung's Disease?
Hirschsprung's Disease is caused by the absence of ganglion cells in the bowel, which is due to a failure of neural crest cells to migrate completely during fetal development.
p.1
Regulation of Pancreatic Secretions
How does the parasympathetic nervous system affect bicarbonate secretion in the pancreas?
It increases watery bicarbonate secretion through the release of acetylcholine (Ach) and vasoactive intestinal peptide (VIP).
p.69
Absorption Mechanisms in the Small Intestine
What is the source of endogenous CO2 in colonocytes?
Endogenous CO2 is produced by oxidative metabolism.
p.4
Regulation of Pancreatic Secretions
What role does CFTR play in the duct cells?
CFTR maintains cellular chloride (Cl-) levels by functioning as a Cl- channel.
p.46
Absorption Mechanisms in the Small Intestine
Which enzyme cleaves amylose and what type of linkage does it target?
Amylase cleaves amylose, targeting the 1-4 linkage.
p.46
Absorption Mechanisms in the Small Intestine
Which enzymes are involved in the digestion of amylopectin?
Amylase cleaves the straight chains, and isomaltase cleaves the dextrins at the 1-6 linkage.
p.68
Absorption Mechanisms in the Small Intestine
What happens to sodium absorption in the colon when its concentration falls below 130 mM?
Sodium absorption ceases.
p.33
Disorders of the Gastrointestinal Tract
What causes the continuous firing of intrinsic inhibitory neurons in Ileus?
The continuous firing is caused by VIP (vasoactive intestinal peptide) or nitric oxide.
p.60
Absorption Mechanisms in the Small Intestine
What is the role of the internal and external anal sphincters during defecation?
During defecation, the internal anal sphincter relaxes involuntarily while the external anal sphincter can be voluntarily controlled to allow or delay the passage of feces.
p.68
Absorption Mechanisms in the Small Intestine
What is the role of the sodium-potassium pump in sodium absorption?
The sodium-potassium pump (3 Na+ out, 2 K+ in) helps maintain the concentration gradient necessary for sodium absorption.
p.51
Role of Bile in Digestion
What is the function of micelles in fat digestion?
Micelles deliver fatty acids and monoglycerides through the unstirred layer.
p.1
Pancreatic Anatomy and Functions
What are the two main types of cells in the pancreas involved in secretion?
Acini and Islets of Langerhans.
p.37
Absorption Mechanisms in the Small Intestine
What is the osmolality of the meal by the time it reaches the jejunum?
The meal becomes hypotonic by the time it reaches the jejunum.
p.77
Disorders of the Gastrointestinal Tract
Which part of the gut does ulcerative colitis involve?
Only the mucosa, with perforation and obstructions usually not seen.
How many microbial cells are present in the human gut microbiota?
Approximately 100 trillion microbial cells.
p.37
Absorption Mechanisms in the Small Intestine
What are the primary substances absorbed by the large intestine?
Water, Na, and other solutes.
p.70
Disorders of the Gastrointestinal Tract
What condition can lead to hypokalemia due to potassium loss in the colon?
Chronic diarrhea or laxative abuse can lead to hypokalemia.
p.20
Gallbladder Function and Gallstone Formation
What exchangers are involved in the concentration of bile in the gallbladder?
Coupled Na/H and Cl/HCO3 exchangers are involved in the concentration of bile in the gallbladder.
p.4
Regulation of Pancreatic Secretions
What happens to bicarbonate transport when there is a loss of CFTR?
There is low bicarbonate transport.
p.20
Gallbladder Function and Gallstone Formation
What is the net effect of the Na/H exchange in the gallbladder?
The Na/H exchange results in a net secretion of H+ ions.
p.14
Liver Functions and Blood Flow
Why is secondary blood flow through the liver important?
It prevents direct access of harmful agents into the body.
p.64
Disorders of the Gastrointestinal Tract
What is the frequency of haustral contractions in the large intestine?
Haustral contractions occur about every 25 minutes.
p.14
Liver Functions and Blood Flow
How are nutrients absorbed from the gut transported to the liver?
They are transported to liver sinusoids.
What are prebiotics and how do they differ from probiotics?
Prebiotics contain no microorganisms; they are substances that stimulate the growth of microorganisms and are components of food that are not digested.
p.33
Disorders of the Gastrointestinal Tract
What symptoms are associated with changes in spike activity, slow wave frequency/velocity, and/or generation of the MMC in the small intestine?
Nausea, abdominal cramping, diarrhea, and/or constipation.
p.64
Disorders of the Gastrointestinal Tract
What are mixing movements in the large intestine?
Mixing movements occur in the proximal colon, shuttling chyme between adjacent haustra without net movement.
p.2
Pancreatic Enzyme Secretion and Activation
What is the role of the apical membrane in pancreatic secretions?
The apical membrane is involved in the transport of ions in pancreatic secretions.
p.71
Absorption Mechanisms in the Small Intestine
Which nutrients are absorbed in the small intestine?
Glucose, galactose, fructose, di/tri peptides, amino acids, fatty acids, monoglycerides, cholesterol, and fat-soluble vitamins.
p.60
Absorption Mechanisms in the Small Intestine
How are chloride and bicarbonate absorbed and secreted in the colon?
Chloride is absorbed in the colon through chloride channels and bicarbonate is secreted in exchange for chloride ions, helping to maintain acid-base balance.
p.42
Absorption Mechanisms in the Small Intestine
What is the function of ferroportin in iron absorption?
Ferroportin transports iron from inside the cell to the bloodstream.
p.60
Disorders of the Gastrointestinal Tract
What are the types of diarrhea?
The types of diarrhea include osmotic diarrhea, secretory diarrhea, inflammatory diarrhea, and motility-related diarrhea.
p.12
Liver Functions and Blood Flow
What is the 'first pass effect'?
The 'first pass effect' refers to the metabolism of a drug in the liver before it reaches systemic circulation, reducing the bioavailability of the drug.
p.7
Regulation of Pancreatic Secretions
What triggers the release of Cholecystokinin (CCK)?
Amino acids and fats in the duodenum.
p.7
Pancreatic Enzyme Secretion and Activation
How does Cholecystokinin (CCK) affect pancreatic enzyme secretion?
It stimulates enzyme secretion from the pancreas.
p.37
Absorption Mechanisms in the Small Intestine
What happens to water when a hypertonic meal enters the gut?
Water will move into the gut to dilute the osmolality of the meal.
p.43
Absorption Mechanisms in the Small Intestine
Which transporter governs the transport of iron across the basolateral membrane?
Ferroportin (FP1) transporter.
p.13
Liver Functions and Blood Flow
What occurs during Phase II reactions in liver detoxification?
Conjugation with glucuronic acid.
p.1
Exocrine and Endocrine Functions of the Pancreas
What is the exocrine function of the pancreas?
Secretion of enzymes by acini cells and bicarbonate by duct cells.
p.13
Liver Functions and Blood Flow
What are two substances excreted by the liver?
Cholesterol and bilirubin.
p.23
Gallbladder Function and Gallstone Formation
What gallbladder factors contribute to the formation of gallstones?
Failure to empty and inflammation, and calcium 'seed' due to water absorption.
p.1
Regulation of Pancreatic Secretions
How does the parasympathetic nervous system affect enzyme secretion in the pancreas?
It increases enzyme secretion through the release of acetylcholine (Ach) and vasoactive intestinal peptide (VIP).
p.23
Gallbladder Function and Gallstone Formation
How does sex bias affect the prevalence of gallstones?
Prevalence in females is 2-3 times higher than in males.
p.30
Absorption Mechanisms in the Small Intestine
What is the role of slow wave frequency in the small intestine?
It accounts for the movement of food from the oral to the anal end of the small intestine.
p.23
Gallbladder Function and Gallstone Formation
What role does excessive cholesterol or calcium play in gallstone formation?
Excessive cholesterol or calcium can lead to the formation of gallstones.
p.69
Absorption Mechanisms in the Small Intestine
What is the overall effect of bicarbonate secretion and chloride absorption in the colon?
It helps maintain acid-base balance by neutralizing bacterial acids and absorbing chloride.
p.2
Pancreatic Enzyme Secretion and Activation
What ions are present in pancreatic secretions and their concentrations?
Na+, Cl-, HCO3-, and K+ are present in pancreatic secretions, with varying concentrations depending on the flow rate.
p.2
Pancreatic Enzyme Secretion and Activation
How does the concentration of Na+ and Cl- in pancreatic secretions change with flow rate?
The concentration of Na+ and Cl- decreases as the flow rate increases.
p.75
Disorders of the Gastrointestinal Tract
Which gender is more affected by IBS?
Women, three times more prevalent.
p.42
Absorption Mechanisms in the Small Intestine
What are the two forms of iron involved in absorption?
Ferric (Fe3+) and Ferrous (Fe2+).
p.4
Regulation of Pancreatic Secretions
What is the full form of CFTR?
Cystic Fibrosis Transmembrane Conductance Regulator.
p.21
Disorders of the Gastrointestinal Tract
What causes obstructive jaundice?
Obstructive jaundice is caused by a blockage of the hepatic duct.
p.60
Absorption Mechanisms in the Small Intestine
How is sodium absorbed in the colon?
Sodium is absorbed in the colon primarily through active transport mechanisms involving sodium channels and sodium-potassium pumps.
p.46
Absorption Mechanisms in the Small Intestine
Which enzymes in the epithelial villi are involved in the final stages of carbohydrate digestion?
Maltase, isomaltase, lactase, and sucrase.
p.68
Absorption Mechanisms in the Small Intestine
How does sodium absorption occur against the concentration gradient?
Through active transport mechanisms such as the sodium-potassium pump.
p.15
Liver Functions and Blood Flow
Describe the parallel vascular arrangement in splanchnic blood flow.
Celiac artery in parallel to the superior mesenteric and inferior mesenteric arteries.
What is necessary for defecation to occur?
Voluntary relaxation of the external anal sphincter is necessary for defecation.
p.17
Role of Bile in Digestion
What are the two types of bile acids?
Primary and secondary bile acids (salts).
p.79
Disorders of the Gastrointestinal Tract
What could pain, bloating, cramping, and blood in stool indicate when accompanied by flatulence?
These symptoms could indicate other underlying conditions.
p.7
Regulation of Pancreatic Secretions
Which neurotransmitters are involved in increasing enzyme and bicarbonate secretion in the pancreas?
Acetylcholine (Ach) and Vasoactive Intestinal Peptide (VIP).
p.11
Disorders of the Gastrointestinal Tract
Which drugs can cause steatorrhea?
Xenical (orlistat), Olestra, and simvastatin (Zocor).
p.63
Absorption Mechanisms in the Small Intestine
How are pacemakers organized in the small intestine?
Pacemakers in the small intestine are organized.
p.55
Absorption Mechanisms in the Small Intestine
How are fatty acids activated for incorporation into chylomicrons?
Fatty acids are activated by CoA ligase to form acyl-CoA.
p.70
Absorption Mechanisms in the Small Intestine
What happens to potassium (K+) in the colon when plasma K+ is greater than 15 mEq/L?
Potassium is absorbed from the lumen.
p.74
Disorders of the Gastrointestinal Tract
How is Hirschsprung's Disease diagnosed?
Hirschsprung's Disease is diagnosed through a combination of physical examination, barium enema, anorectal manometry, and rectal biopsy.
p.67
Absorption Mechanisms in the Small Intestine
What substances does the mammalian large intestine absorb?
The mammalian large intestine absorbs sodium, chloride, and water.
p.75
Disorders of the Gastrointestinal Tract
What is the most common complaint regarding the gut?
Irritable Bowel Syndrome (IBS).
p.70
Absorption Mechanisms in the Small Intestine
What is the required potassium (K+) concentration that must be maintained in the plasma?
Potassium concentration must be maintained at 4 to 5 mM.
p.38
Absorption Mechanisms in the Small Intestine
How does Amiloride work in the body?
Amiloride blocks the reabsorption of sodium in the intestines and kidneys, helping to treat high blood pressure.
p.70
Absorption Mechanisms in the Small Intestine
How does potassium (K+) move in the colonocyte when the lumen is negative?
Potassium moves down the electrochemical gradient.
p.75
Disorders of the Gastrointestinal Tract
What bowel habits can IBS patients experience?
Constipation and/or diarrhea.
p.19
Absorption Mechanisms in the Small Intestine
How does a high fiber diet affect the time feces spend in the colon?
A high fiber diet reduces the time feces spend in the colon.
p.39
Absorption Mechanisms in the Small Intestine
Where does transcellular calcium absorption occur in the small intestine?
In the duodenum, facilitated by Vitamin D.
p.19
Absorption Mechanisms in the Small Intestine
How does fiber intake relate to heart disease?
Fiber lowers serum cholesterol, which is beneficial for heart disease.
p.30
Absorption Mechanisms in the Small Intestine
What is the frequency of slow waves in the proximal small intestine?
Approximately 12 per minute.
p.21
Disorders of the Gastrointestinal Tract
What is hemolytic jaundice and what causes it?
Hemolytic jaundice is caused by the excessive breakdown of red blood cells (RBCs).
p.46
Absorption Mechanisms in the Small Intestine
What are the basic units of carbohydrates that are absorbed?
Monosaccharides: glucose, galactose, and fructose.
p.71
Absorption Mechanisms in the Small Intestine
What is absorbed in the terminal ileum?
Vitamin B12 and bile salts.
p.30
Absorption Mechanisms in the Small Intestine
What does ICC stand for in the context of small intestine electrical activity?
Interstitial Cells of Cajal.
What happens when feces enter the rectum?
The rectum distends, initiating afferent signals that start peristaltic waves to move feces towards the anus.
p.71
Absorption Mechanisms in the Small Intestine
What is absorbed in the colon?
Short-chain fatty acids from bacteria.
p.81
Disorders of the Gastrointestinal Tract
How can changes in the gut microbiome affect mental health?
Alterations in the gut microbiome have been linked to mental health conditions such as anxiety, depression, and stress-related disorders.
p.33
Disorders of the Gastrointestinal Tract
What effect does peritoneal irritation, such as handling the gut during surgery, have on the small intestine?
It can lead to Ileus by suppressing excitatory firing of the myenteric plexus and hyperpolarizing smooth muscle.
p.42
Absorption Mechanisms in the Small Intestine
Why is the iron absorption process described as 'easily saturated'?
Because the body's capacity to absorb iron is limited and can be quickly overwhelmed.
p.60
Disorders of the Gastrointestinal Tract
What mechanisms contribute to gas in the GI tract?
Mechanisms that contribute to gas in the GI tract include swallowing air, bacterial fermentation of undigested carbohydrates, and diffusion of gases from the bloodstream into the intestines.
What is the effect of spinal cord injury on defecation?
Spinal cord injury can result in the loss of voluntary relaxation of the external anal sphincter.
p.7
Regulation of Pancreatic Secretions
What is the role of Secretin in pancreatic and liver function?
It stimulates the secretion of bicarbonate (HCO3-) ions from pancreatic and liver duct cells.
p.11
Disorders of the Gastrointestinal Tract
What is steatorrhea and what causes it in the context of pancreatitis?
Steatorrhea is the presence of fatty stools, caused by the loss of pancreatic lipase.
p.63
Absorption Mechanisms in the Small Intestine
What is the transit time in the large intestine?
The transit time in the large intestine is measured in days.
p.45
Absorption Mechanisms in the Small Intestine
What enzymes are involved in protein digestion in the small intestine?
Trypsin, chymotrypsin, and carboxypeptidase.
p.38
Absorption Mechanisms in the Small Intestine
What drug blocks the reabsorption of sodium and is used to treat high blood pressure?
Amiloride (Midamor) blocks the reabsorption of sodium and is used to treat high blood pressure.
p.10
Regulation of Pancreatic Secretions
What triggers the intestinal phase of pancreatic secretion?
Chyme entering the small intestine.
p.34
Pancreatic Anatomy and Functions
What is the function of the submucosal plexus (Meissner’s plexus) in the small intestine?
The submucosal plexus (Meissner’s plexus) regulates enzyme secretion, blood flow, and ion/water transport.
p.14
Liver Functions and Blood Flow
What is the role of reticuloendothelial cells in the liver?
They remove bacteria and particulates from the blood.
p.6
Pancreatic Enzyme Secretion and Activation
What is the role of pancreatic amylase?
Pancreatic amylase hydrolyzes starches, glycogen, and other carbohydrates to form tri- and disaccharides.
p.10
Regulation of Pancreatic Secretions
What is the role of CCK in pancreatic secretion?
CCK stimulates pancreatic enzyme secretion.
p.64
Disorders of the Gastrointestinal Tract
What are mass movements in the large intestine?
Mass movements are large contractions of the colon that move fecal material towards the rectum, leading to the defecation reflex. They involve long bursts of spike potentials.
Is there conclusive evidence on the health benefits of prebiotics?
No, the jury is still out on any definitive health benefits of prebiotics.
p.60
Absorption Mechanisms in the Small Intestine
What are the primary functions of the colon?
The primary functions of the colon include absorbing water and electrolytes, forming and storing feces, and fermenting indigestible food matter with the help of gut bacteria.
p.30
Absorption Mechanisms in the Small Intestine
What is the frequency of slow waves in the distal small intestine?
Approximately 8 per minute.
p.39
Absorption Mechanisms in the Small Intestine
What hormone is involved in the regulation of calcium levels in the extracellular fluid?
Parathyroid hormone (PTH).
p.81
Disorders of the Gastrointestinal Tract
What role do neurotransmitters play in the gut-brain axis?
Neurotransmitters produced by gut bacteria, such as serotonin and gamma-aminobutyric acid (GABA), can affect brain function and behavior.
p.21
Disorders of the Gastrointestinal Tract
What is physiologic hyperbilirubinemia (neonatal jaundice) and what are its causes?
Physiologic hyperbilirubinemia, or neonatal jaundice, affects about 50% of newborns and is caused by excessive bilirubin production due to rapid breakdown of RBCs and immature hepatocyte function, leading to limited uptake, conjugation, and excretion of bilirubin.
How does the external anal sphincter (EAS) respond to rectal distention?
The external anal sphincter contracts to maintain continence.
p.60
Disorders of the Gastrointestinal Tract
What are irritable bowel syndrome, Crohn’s disease, and ulcerative colitis?
Irritable bowel syndrome (IBS) is a functional GI disorder characterized by abdominal pain and altered bowel habits. Crohn’s disease and ulcerative colitis are types of inflammatory bowel disease (IBD) that cause chronic inflammation of the GI tract.
p.5
Pancreatic Enzyme Secretion and Activation
What is the function of trypsin inhibitor?
Trypsin inhibitor stops the premature activation of trypsin in the pancreas or pancreatic duct.
p.17
Role of Bile in Digestion
How is cholesterol involved in bile production?
Cholesterol is synthesized by the liver and absorbed from the diet; it is a component of cell membranes and is used in the synthesis of steroid hormones and bile acids.
What is the difference between real and perceived pressure in the context of defecation?
Real pressure refers to the actual pressure within the rectum, while perceived pressure is the sensation of needing to defecate.
p.7
Regulation of Pancreatic Secretions
What is the effect of Cholecystokinin (CCK) on gastric motility?
It decreases gastric motility.
p.1
Regulation of Pancreatic Secretions
How does the sympathetic nervous system affect the pancreas?
It decreases blood flow through the release of norepinephrine (NE).
How has the gut microbiome evolved with humans?
Species of bacteria codiversified with humans as they spread across the globe and have kept fidelity to human lineages for thousands of generations.
p.70
Absorption Mechanisms in the Small Intestine
Why is the lumen of the colon negative?
The lumen is negative due to the electrochemical gradient.
p.4
Regulation of Pancreatic Secretions
What is the consequence of low bicarbonate transport in the ducts?
It leads to a 'sticky' protein solution and less water movement to the duct.
p.64
Disorders of the Gastrointestinal Tract
What are haustral contractions in the large intestine?
Haustral contractions are slow, uncoordinated segmental contractions that occur about every 25 minutes, filling the haustra with chyme and resulting in net movement down the colon.
p.35
Absorption Mechanisms in the Small Intestine
What is the total increase in surface area provided by ridges, villi, and microvilli in the small intestine?
The total increase in surface area is 600-fold.
p.71
Absorption Mechanisms in the Small Intestine
What is absorbed in the duodenum?
Calcium (Ca2+) and Iron (Fe2+).
p.35
Absorption Mechanisms in the Small Intestine
What is the absorptive unit of the small intestine?
The absorptive unit of the small intestine includes enterocytes, villi, and microvilli.
p.71
Absorption Mechanisms in the Small Intestine
Which nutrients are absorbed in the jejunum?
Calcium (Ca2+), Iron (Fe2+), and water-soluble vitamins such as folic acid.
p.6
Pancreatic Enzyme Secretion and Activation
What is the function of carboxyl ester lipase (bile salt dependent lipase, BSDL)?
Carboxyl ester lipase hydrolyzes triglycerides and is present in breast milk to help infants digest fats due to their lack of BSDL.
p.14
Liver Functions and Blood Flow
What is the exception to the First Pass Effect in drug absorption?
Rectal administration of drugs or alcohol.
p.33
Disorders of the Gastrointestinal Tract
What is Ileus (Paralytic Ileus) and what characterizes it?
Ileus is a state of no muscle contractility for a long period of time, characterized by the presence of slow waves but no spike potentials.
p.15
Liver Functions and Blood Flow
What are the two types of vascular arrangements in splanchnic blood flow?
Parallel and series vascular arrangements.
p.17
Role of Bile in Digestion
What influences the amount of bile acids formed?
The amount formed is dependent upon reabsorption.
p.5
Pancreatic Enzyme Secretion and Activation
What is enteropeptidase and where is it secreted?
Enteropeptidase, also known as enterokinase, is secreted by the intestinal mucosa.
p.15
Liver Functions and Blood Flow
What is the formula for total resistance in a parallel vascular arrangement?
RT = 1 / (1/R1 + 1/R2 + 1/R3 + 1/R4).
p.5
Pancreatic Enzyme Secretion and Activation
What is the role of enteropeptidase in enzyme activation?
Enteropeptidase cleaves trypsinogen to trypsin, which then activates other 'pro' enzymes.
p.17
Role of Bile in Digestion
What role do micelles play in digestion?
Micelles, composed of phospholipids, aid in the absorption of fats.
p.12
Gallbladder Function and Gallstone Formation
What is the function of the gallbladder?
The gallbladder stores and concentrates bile produced by the liver until it is needed for digestion.
p.15
Liver Functions and Blood Flow
What happens if one component is interrupted in a series vascular arrangement?
All is lost because all devices are connected along the loop.
p.15
Liver Functions and Blood Flow
What happens if one component is interrupted in a parallel vascular arrangement?
Other paths are fine and take over for the loss.
p.17
Role of Bile in Digestion
What is the function of sodium, calcium, potassium, chloride, and bicarbonate in bile?
These components help neutralize stomach acid.
p.16
Liver Functions and Blood Flow
What is bilirubin and how is it produced?
Bilirubin is a yellow compound that occurs in the normal catabolic pathway that breaks down heme in red blood cells.
p.7
Regulation of Pancreatic Secretions
What is the enteropancreatic reflex and what triggers it?
It is an increase in pancreatic secretion in response to fats or proteins in the duodenum.
p.35
Absorption Mechanisms in the Small Intestine
How much do ridges increase the surface area in the small intestine?
Ridges increase the surface area by 3-fold.
p.35
Absorption Mechanisms in the Small Intestine
How much do villi increase the surface area in the small intestine?
Villi increase the surface area by 10-fold.
p.67
Absorption Mechanisms in the Small Intestine
Is there active transport of nutrients in the mammalian large intestine?
No, there is no active transport of nutrients in the mammalian large intestine.
p.35
Absorption Mechanisms in the Small Intestine
How much do microvilli increase the surface area in the small intestine?
Microvilli increase the surface area by 20-fold.
What health conditions are influenced by the gut microbiota?
Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD), obesity, Type 2 diabetes, essential hypertension, among others.
p.69
Absorption Mechanisms in the Small Intestine
What is the function of H+ ions in the colonocyte during bicarbonate secretion?
H+ ions are exchanged for Cl- ions from the lumen.
p.6
Pancreatic Enzyme Secretion and Activation
What is the major form of dietary fat and why is it not absorbed directly?
The major form of dietary fat is triglycerides, which are not absorbed directly because they need to be split into fatty acids and 2-monoglyceride.
p.30
Absorption Mechanisms in the Small Intestine
What are spike potentials in the context of small intestine activity?
Spike potentials are the electrical activities that occur on top of slow waves, facilitating muscle contractions.
p.81
Disorders of the Gastrointestinal Tract
What is the gut-brain axis?
The gut-brain axis is a bidirectional communication system between the gut and the brain, involving neural, hormonal, and immunological pathways.
p.42
Absorption Mechanisms in the Small Intestine
What is the role of ferritin in iron absorption?
Ferritin stores iron in the cells.
p.33
Disorders of the Gastrointestinal Tract
What happens during a spasm of the circular muscle layer in the small intestine?
There is a lack of activity of inhibitory neurons, and the cells, connected by gap junctions, transmit activity due to the syncytial properties of the smooth muscle cells.
p.12
Liver Functions and Blood Flow
What are some important functions of the liver?
The liver is responsible for detoxification, protein synthesis, production of biochemicals necessary for digestion, and regulation of glycogen storage, among other functions.
p.17
Enterohepatic Circulation
What is enterohepatic circulation?
The recycling process of bile acids from the intestine back to the liver.
What happens to the internal anal sphincter (IAS) after the initial reflex?
The internal anal sphincter usually regains its tone after the initial weak reflex, allowing the rectum to relax.
p.3
Pancreatic Enzyme Secretion and Activation
What happens to the bicarbonate once it is produced in the ductal cells?
It is secreted into the duct lumen.
What maneuver can aid in defecation by increasing abdominal pressure?
The Valsalva maneuver can aid in defecation by increasing abdominal pressure.
p.5
Pancreatic Enzyme Secretion and Activation
What are endopeptidases and exopeptidases?
Endopeptidases and exopeptidases are types of enzymes released from the pancreas that break down proteins.
p.16
Liver Functions and Blood Flow
What role do bacteria in the intestine play in bilirubin metabolism?
Bacteria in the intestine convert bilirubin glucuronide into urobilinogen.
p.79
Disorders of the Gastrointestinal Tract
Is explosive flatulence a bad thing?
No, it is just related to the amount of gas built up in the rectum.
p.11
Disorders of the Gastrointestinal Tract
What are the characteristics of stools in steatorrhea?
Pale, foul-smelling, bulky stools with an oily appearance.
p.63
Absorption Mechanisms in the Small Intestine
What type of movement is observed in the small intestine?
The small intestine exhibits continuous movement.
p.23
Gallbladder Function and Gallstone Formation
How do contraceptives contribute to gallstone formation?
Contraceptives, which contain progesterone and estrogen, impair gallbladder emptying and cause hypersecretion of cholesterol into bile.
p.2
Pancreatic Enzyme Secretion and Activation
What is one of the main purposes of pancreatic secretions?
To neutralize acid with an alkaline solution.
How do probiotics provide protection to the host?
Probiotics influence oxidative stress, platelets, TMAO levels, inflammation, and/or cholesterol.
p.4
Regulation of Pancreatic Secretions
How does secretin affect the duct cells?
Secretin stimulates the secretion of bicarbonate (HCO3-) into the duct lumen.
p.81
Disorders of the Gastrointestinal Tract
What is the gut microbiome?
The gut microbiome refers to the community of microorganisms, including bacteria, viruses, fungi, and other microbes, that inhabit the digestive tract.
p.4
Regulation of Pancreatic Secretions
What enzyme is involved in the production of bicarbonate in duct cells?
Carbonic anhydrase (CA) is involved in the production of bicarbonate.
p.46
Absorption Mechanisms in the Small Intestine
Where does carbohydrate digestion occur?
In the mouth, stomach, and small intestine.
p.39
Absorption Mechanisms in the Small Intestine
What is the role of 1,25-(OH)2 D3 in calcium absorption?
It aids in tubular resorption of calcium in the kidneys.
p.12
Liver Functions and Blood Flow
What is splanchnic blood flow?
Splanchnic blood flow refers to the blood flow to the gastrointestinal organs including the stomach, liver, spleen, pancreas, and intestines.
p.3
Pancreatic Enzyme Secretion and Activation
What role does the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) play in bicarbonate secretion?
CFTR maintains cellular chloride levels and functions as a chloride channel.
p.12
Enterohepatic Circulation
What is enterohepatic circulation and its significance in bile synthesis?
Enterohepatic circulation is the recycling of bile acids from the intestine to the liver. It is significant because it conserves bile acids and regulates their synthesis.
p.15
Liver Functions and Blood Flow
What analogy is used to explain the difference between series and parallel vascular arrangements?
The wiring in a house: series arrangement is like a closed circuit where all devices are connected along the loop, while parallel arrangement is like a closed circuit that divides into multiple paths.
p.3
Regulation of Pancreatic Secretions
What is the significance of bicarbonate secretion in the duodenum?
Bicarbonate neutralizes the acid in the duodenum, creating an optimal pH for digestive enzymes.
p.5
Pancreatic Enzyme Secretion and Activation
What are the active forms of the enzymes activated by trypsin?
The active forms are chymotrypsin, elastase, carboxypolypeptidase A & B, aminopeptidase, and phospholipase A2.
p.12
Gallbladder Function and Gallstone Formation
How are gallstones formed?
Gallstones are formed when substances in bile, such as cholesterol or bilirubin, harden into stone-like particles. This can occur due to imbalances in the substances that make up bile.
p.79
Disorders of the Gastrointestinal Tract
What causes the odor of flatus?
The odor of fecal material, primarily from hydrogen sulfide and indoles (skatole) from foods eaten.
p.79
Disorders of the Gastrointestinal Tract
Is flatulence normal and how often does it occur?
Yes, it is normal and can occur more than 20 times a day.
p.16
Liver Functions and Blood Flow
What is bilirubin glucuronide and how is it formed?
Bilirubin glucuronide is formed when bilirubin is conjugated with glucuronic acid in the liver.
p.16
Liver Functions and Blood Flow
What is the color of stercobilin and where is it found?
Stercobilin is brown and is found in feces.
p.63
Absorption Mechanisms in the Small Intestine
Is there a gradient in slow wave frequency in the large intestine?
No, there is no gradient in slow wave frequency in the large intestine.
p.63
Absorption Mechanisms in the Small Intestine
Is retrograde movement common in the large intestine?
Yes, retrograde movement is frequently observed in the large intestine.
p.63
Absorption Mechanisms in the Small Intestine
How are pacemakers organized in the large intestine?
Pacemakers in the large intestine are not organized.
p.67
Absorption Mechanisms in the Small Intestine
How does the colon absorb Na+ against a concentration gradient?
The colon absorbs Na+ against a concentration gradient, with Na+ concentration inside epithelial cells at 15 mM and outside (basolateral) at 140 mM.
p.46
Absorption Mechanisms in the Small Intestine
What are the two types of starch and their characteristics?
Amylose, which consists of straight chains of glucose (20% of dietary starch), and amylopectin, which has highly branched chains of glucose (80% of dietary starch).
p.6
Pancreatic Enzyme Secretion and Activation
What enzyme splits fats into fatty acids and 2-monoglyceride?
Pancreatic lipase splits fats into fatty acids and 2-monoglyceride.
p.64
Disorders of the Gastrointestinal Tract
What triggers the defecation reflex in the large intestine?
The defecation reflex is triggered when fecal material reaches the rectum due to mass movements.
p.39
Disorders of the Gastrointestinal Tract
What condition is caused by a lack of the active form of Vitamin D?
Rickets (osteomalacia), which leads to soft bones, bowed legs, and stunted growth.
p.68
Absorption Mechanisms in the Small Intestine
Why is water transport more efficient in the colon?
Because 99% of sodium presented to the colon is absorbed.
p.60
Absorption Mechanisms in the Small Intestine
How is potassium transported in the colon?
Potassium is transported in the colon through both passive diffusion and active transport mechanisms, depending on the body's needs.
p.81
Disorders of the Gastrointestinal Tract
How might probiotics benefit the gut-brain axis?
Probiotics, which are beneficial bacteria, may help restore a healthy balance in the gut microbiome and positively impact brain function and mental health.
p.16
Liver Functions and Blood Flow
How is bilirubin transported in the blood?
Bilirubin is bound to plasma albumin for transport in the blood.
p.11
Disorders of the Gastrointestinal Tract
What vitamins are lost due to steatorrhea?
Fat-soluble vitamins A, D, E, and K.
p.10
Regulation of Pancreatic Secretions
How do proteins and fats affect the vagovagal reflex during the intestinal phase?
Proteins and fats stimulate the vagovagal reflex to stimulate acinar cells.
p.71
Absorption Mechanisms in the Small Intestine
What is absorbed in the ileum?
Water-soluble vitamins such as ascorbic acid.
p.81
Disorders of the Gastrointestinal Tract
How does the gut microbiome influence the brain?
The gut microbiome can influence the brain through the gut-brain axis, which involves biochemical signaling between the gastrointestinal tract and the central nervous system.
p.39
Absorption Mechanisms in the Small Intestine
What is the role of the small intestine in calcium absorption?
To maintain extracellular levels of calcium at 2.5 mM.
p.64
Disorders of the Gastrointestinal Tract
Where do mixing movements occur in the large intestine?
Mixing movements occur in the proximal colon.
p.44
Regulation of Pancreatic Secretions
How does chloride (Cl-) accumulate in crypt cells?
Driven by Na/K ATPase, which allows Cl- to accumulate in the cell.
p.15
Liver Functions and Blood Flow
Describe the series vascular arrangement in splanchnic blood flow.
Aorta - superior mesenteric artery - intestinal arterioles - venules - portal vein, with a pressure drop at each area.
What is the role of the internal anal sphincter (IAS) during defecation?
The internal anal sphincter relaxes as part of the recto-sphincteric reflex, which is a parasympathetic reflex.
p.21
Disorders of the Gastrointestinal Tract
What serious condition can result from high levels of bilirubin in newborns?
Kernicterus, which is brain damage due to high levels of bilirubin.
p.44
Disorders of the Gastrointestinal Tract
What is a common treatment for conditions affecting cellular secretion in the gut?
Rehydration with Na+/Glucose.
p.3
Pancreatic Enzyme Secretion and Activation
How does the CFTR channel contribute to the secretion of bicarbonate?
By allowing chloride ions to exit the ductal cell, which facilitates the exchange of chloride for bicarbonate.
p.5
Pancreatic Enzyme Secretion and Activation
What happens to trypsinogen in the lumen of the small intestine?
Trypsinogen is cleaved by enteropeptidase to form trypsin.
p.16
Liver Functions and Blood Flow
What is the primary function of red blood cells?
To transport oxygen (O2) throughout the body.
p.44
Regulation of Pancreatic Secretions
What is the role of the triporter in chloride accumulation?
The triporter helps move chloride (Cl-) into the cell for secretion.
p.12
Disorders of the Gastrointestinal Tract
What is jaundice and what mechanisms contribute to it?
Jaundice is a condition characterized by yellowing of the skin and eyes due to high levels of bilirubin in the blood. It can be caused by liver disease, bile duct obstruction, or excessive breakdown of red blood cells.
p.79
Disorders of the Gastrointestinal Tract
Is retaining gas unhealthy?
It depends. If it leads to back pain, bloating, distention of the colon, and rectal pain, then yes.
p.63
Absorption Mechanisms in the Small Intestine
Is there a gradient in slow wave frequency in the small intestine?
Yes, there is a gradient in slow wave frequency in the small intestine.
p.63
Absorption Mechanisms in the Small Intestine
Is retrograde movement common in the small intestine?
Retrograde movement is not normally observed in the small intestine.
p.60
Absorption Mechanisms in the Small Intestine
What are the different motility patterns in the colon?
The different motility patterns in the colon include segmental contractions, peristaltic movements, and mass movements.
p.60
Absorption Mechanisms in the Small Intestine
How does colon motor activity change before and after a meal?
Before a meal, the colon exhibits a baseline level of motor activity. Following a meal, the gastrocolic reflex increases motor activity, leading to mass movements that help move fecal matter towards the rectum.
p.46
Absorption Mechanisms in the Small Intestine
What role does salivary amylase play in carbohydrate digestion?
Salivary amylase, produced by the parotid gland, initiates carbohydrate digestion in the mouth but is inactivated by the low pH in the stomach.
p.44
Regulation of Pancreatic Secretions
What follows the movement of chloride (Cl-) into the intestinal lumen?
Water follows the movement of chloride into the intestinal lumen.
p.17
Role of Bile in Digestion
What are bilirubin and biliverdin, and how are they excreted?
Bilirubin (yellow) and biliverdin (green) are bile pigments excreted in feces and urine.
p.16
Liver Functions and Blood Flow
What is the role of the reticuloendothelial system (RES) in bilirubin metabolism?
The RES, which includes the liver, bone marrow, spleen, lymph nodes, lungs, blood, and connective tissue, helps in the breakdown of red blood cells and the production of bilirubin.
p.6
Pancreatic Enzyme Secretion and Activation
How is colipase activated and what is its role?
Colipase is activated when trypsin cleaves procolipase to colipase, and it acts as a receptor site for pancreatic lipase.
p.33
Disorders of the Gastrointestinal Tract
How do anesthetics and narcotics affect peristalsis in the small intestine?
Anesthetics and narcotics inhibit peristalsis.
p.44
Regulation of Pancreatic Secretions
What happens to chloride (Cl-) when it is necessary for secretion?
Cl- moves into the intestinal lumen.
p.39
Disorders of the Gastrointestinal Tract
How does impaired vascular function relate to Vitamin D?
It is linked to the loss of Vitamin D, affecting endothelial nitric oxide synthase (eNOS).
p.60
Disorders of the Gastrointestinal Tract
What is constipation?
Constipation is defined as infrequent or difficult bowel movements, often associated with hard and dry stools.
p.15
Liver Functions and Blood Flow
Why is there no loss in driving pressure for each segment in a parallel vascular arrangement?
Because the circuit divides into two or more paths, allowing other paths to take over if one is interrupted.
p.44
Disorders of the Gastrointestinal Tract
What is the effect of cholera toxin on cellular secretion?
Cholera toxin stimulates excessive secretion by increasing cAMP levels.
p.7
Regulation of Pancreatic Secretions
What effect does Cholecystokinin (CCK) have on the gallbladder?
It stimulates the contraction of the gallbladder and relaxes the sphincter of Oddi, allowing bile to flow into the small intestine.
p.63
Absorption Mechanisms in the Small Intestine
What is the storage function of the small intestine?
The small intestine does not have a storage function.
p.79
Disorders of the Gastrointestinal Tract
Do women pass less gas than men?
No, women pass as much gas as men.
p.7
Regulation of Pancreatic Secretions
What initiates vagovagal reflexes in the digestive system?
The entry of chyme into the duodenum.
p.11
Disorders of the Gastrointestinal Tract
How does alcohol abuse contribute to pancreatitis?
It induces a change in the ratio of trypsinogen/trypsin inhibitor, leading to active trypsin which is very painful.
p.11
Disorders of the Gastrointestinal Tract
Why can't lingual lipase break down all lipids in steatorrhea?
Due to limited exposure and its optimal pH being 4.5 - 5.5.
p.30
Absorption Mechanisms in the Small Intestine
How does the electrical activity of ICC compare to the slow waves in the small intestine?
The electrical activity of ICC is slower than the slow waves.
p.42
Absorption Mechanisms in the Small Intestine
What is apoferritin?
Apoferritin is the protein shell of ferritin that binds to iron.
p.81
Disorders of the Gastrointestinal Tract
What are some factors that can influence the composition of the gut microbiome?
Diet, antibiotics, stress, and lifestyle factors can all influence the composition of the gut microbiome.
p.44
Regulation of Pancreatic Secretions
What is the role of the CFTR protein in cellular secretion?
CFTR helps move chloride (Cl-) into the intestinal lumen.
p.12
Liver Functions and Blood Flow
How do the liver, intestine, and kidneys work together to eliminate waste products?
The liver metabolizes waste products and toxins, the intestine absorbs nutrients and excretes waste, and the kidneys filter blood to produce urine, eliminating waste from the body.
p.5
Pancreatic Enzyme Secretion and Activation
Which enzymes are activated by trypsin in the small intestine?
Trypsin activates chymotrypsinogen, proelastase, procarboxypolypeptidase A & B, proaminopeptidase, and prophospholipase A2.
p.63
Absorption Mechanisms in the Small Intestine
What is the transit time in the small intestine?
The transit time in the small intestine is measured in hours.
p.63
Absorption Mechanisms in the Small Intestine
How is the longitudinal muscle organized in the small intestine?
The longitudinal muscle in the small intestine is continuous.
p.21
Disorders of the Gastrointestinal Tract
What is a common treatment for neonatal jaundice?
Exposure to sunlight to aid in the breakdown of bilirubin to lumirubin.
p.44
Regulation of Pancreatic Secretions
What are some mechanisms by which cellular secretion can be stimulated?
Prostaglandins, acetylcholine, vasoactive intestinal polypeptide, and ionic mechanisms like cAMP and Ca2+.
p.3
Regulation of Pancreatic Secretions
What is the effect of secretin on ductal cells?
Secretin stimulates the ductal cells to secrete a watery bicarbonate solution.
p.12
Gallbladder Function and Gallstone Formation
How is bile modified in the gallbladder?
In the gallbladder, bile is concentrated by the absorption of water and electrolytes.
p.79
Disorders of the Gastrointestinal Tract
Which gases are produced by bacterial actions in the large intestine?
Carbon dioxide, methane, hydrogen, nitrogen, and oxygen.
p.16
Liver Functions and Blood Flow
What is hemoglobin and its role in red blood cells?
Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to the rest of the body.
p.5
Pancreatic Enzyme Secretion and Activation
What is the significance of enzyme digestion in the small intestine?
Enzymes digest one another to form a component of daily absorbed proteins.
p.16
Liver Functions and Blood Flow
What enzyme is involved in the conjugation of bilirubin in the liver?
UDP-glucuronyl transferase (UDP-GT) is the enzyme involved in the conjugation of bilirubin with glucuronic acid.
p.63
Absorption Mechanisms in the Small Intestine
What is the storage function of the large intestine?
The large intestine has a storage function.
p.11
Disorders of the Gastrointestinal Tract
How does cystic fibrosis affect pancreatic function?
It causes a lack of bicarbonate transport to the lumen of the gland, leading to precipitation of secreted proteins (enzymes) and dehydrated, thick secretions.
p.17
Role of Bile in Digestion
What are the primary and secondary bile acids mentioned in the text?
Primary bile acids include cholic acid and chenodeoxycholic acid; secondary bile acids include sulfolithocholic acid and ursodeoxycholic acid.
p.79
Disorders of the Gastrointestinal Tract
Does stinky flatulence indicate a health concern?
No, it just indicates what you may have eaten.
p.16
Liver Functions and Blood Flow
What happens to urobilinogen in the body?
Urobilinogen can be reabsorbed and excreted by the kidneys as urobilin in urine or converted to stercobilin and excreted in feces.
p.79
Disorders of the Gastrointestinal Tract
Is painful flatulence a bad sign?
Not necessarily. It is most likely related to irritation such as hemorrhoids or anal fissure.
p.63
Absorption Mechanisms in the Small Intestine
How is the longitudinal muscle organized in the large intestine?
The longitudinal muscle in the large intestine is organized in discrete bands.
p.11
Disorders of the Gastrointestinal Tract
How can gallstones lead to pancreatitis?
By blocking the papilla of Vater, causing pancreatic enzymes to accumulate in the duct, overcome the effect of trypsin inhibitor, and digest the pancreas.
p.16
Liver Functions and Blood Flow
What is the significance of the liver, kidney, and intestine in bilirubin metabolism?
The liver, kidney, and intestine all work together to metabolize and excrete bilirubin from the body.
p.63
Absorption Mechanisms in the Small Intestine
Does the small intestine exhibit Migrating Motor Complex (MMC)?
Yes, the small intestine exhibits Migrating Motor Complex (MMC).
p.63
Absorption Mechanisms in the Small Intestine
What type of movement is observed in the large intestine?
The large intestine exhibits mass movement.
p.63
Absorption Mechanisms in the Small Intestine
Does the large intestine exhibit Migrating Motor Complex (MMC)?
No, the large intestine does not exhibit Migrating Motor Complex (MMC).
