Medicine Marrow Pg 1-10 (GIT)
53 Questions
4 Views

Medicine Marrow Pg 1-10 (GIT)

Created by
@ArdentHouston

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is a common viral cause of diarrhea lasting less than 2 weeks?

  • Cholera
  • Shigella
  • Viral (correct)
  • ETEC

    • Campylobacter is classified as a secretory organism causing diarrhea lasting over 4 weeks.

    False

    What type of diarrhea is characterized by abdominal cramps, fever, and blood in the stool?

    Invasive organisms

    Diarrhea lasting longer than 4 weeks may include a type known as __________ colitis.

    <p>ulcerative</p> Signup and view all the answers

    Match the type of diarrhea with its description:

    <p>Osmotic = Increased stool osmotic gap, improves on fasting Secretory = Caused by VIPomas Inflammatory = Associated with conditions like Ulcerative colitis Invasive = Caused by organisms like Shigella and Salmonella</p> Signup and view all the answers

    What role do Brunner's glands play in the digestive system?

    <p>Secrete bicarbonate</p> Signup and view all the answers

    The body pool of bile acids is maintained by the enterohepatic circulation.

    <p>True</p> Signup and view all the answers

    What are the primary components formed when triglycerides are broken down during fat absorption?

    <p>Fatty acids, glycerol, and phospholipids</p> Signup and view all the answers

    During fat absorption, bile acids are conjugated with _______ or taurine in the liver.

    <p>glycine</p> Signup and view all the answers

    Match the following components of the intestinal wall with their functions:

    <p>Submucosa = Contains Brunner's glands and Peyer's patches Muscularis Propria = Responsible for peristalsis Serosa = Protective outer layer of the intestine</p> Signup and view all the answers

    What is a common etiology of small intestinal diarrhea?

    <p>Vibrio cholera</p> Signup and view all the answers

    In large intestinal diarrhea, pus, blood, or mucus is typically absent.

    <p>False</p> Signup and view all the answers

    What symptom is present in both small and large intestinal diarrhea?

    <p>Abdominal cramps</p> Signup and view all the answers

    In small intestinal diarrhea, the stool odorous finding is likely to be __________.

    <p>watery</p> Signup and view all the answers

    Which of the following symptoms is typically absent in small intestinal diarrhea?

    <p>Tenesmus</p> Signup and view all the answers

    Match the following features with small or large intestinal diarrhea:

    <p>Pus/blood/mucus = Absent Digested fat in stool = Present Tenesmus = Present Volume = Large</p> Signup and view all the answers

    Weight loss is commonly absent in large intestinal diarrhea.

    <p>True</p> Signup and view all the answers

    Name one symptom that may be present in small intestinal diarrhea but rare in large intestinal diarrhea.

    <p>Vomiting</p> Signup and view all the answers

    Which type of diarrhea is most commonly seen in children?

    <p>Rotavirus</p> Signup and view all the answers

    Type 6 stools indicate severe diarrhea according to the Bristol stool chart.

    <p>False</p> Signup and view all the answers

    What is the maximum absorption site for nutrients in the body?

    <p>Small intestine</p> Signup and view all the answers

    Most calorie-dense nutrient is ____.

    <p>Fat</p> Signup and view all the answers

    Match the following Bristol stool types with their descriptions:

    <p>Type 1 = Separate hard lumps Type 4 = Like a smooth, soft sausage or snake Type 6 = Mushy consistency with ragged edges Type 7 = Liquid consistency with no solid pieces</p> Signup and view all the answers

    Which of the following organisms is associated with secretory diarrhea?

    <p>Escherichia coli (ETEC)</p> Signup and view all the answers

    Secretory diarrhea shows an increased osmotic gap in the stool.

    <p>False</p> Signup and view all the answers

    Name one tumor associated with secretory diarrhea.

    <p>VIPoma</p> Signup and view all the answers

    Patients with secretory diarrhea may experience __________ as a result of electrolyte loss.

    <p>hypokalemia</p> Signup and view all the answers

    Match the following features with the type of diarrhea:

    <p>Stool osmotic gap &lt; 50 mOsm/kg = Secretory Diarrhea Stool osmotic gap &gt; 100 mOsm/kg = Osmotic Diarrhea No change with fasting = Secretory Diarrhea Improvement with fasting = Osmotic Diarrhea</p> Signup and view all the answers

    Which enzyme is responsible for activating trypsinogen?

    <p>Enterokinase</p> Signup and view all the answers

    Cystinuria is associated with a defect in the transport of dibasic amino acids.

    <p>True</p> Signup and view all the answers

    Name a congenital cause of lactose intolerance.

    <p>Absent enzyme from birth</p> Signup and view all the answers

    Lactose is broken down into ________ and galactose by the enzyme lactase.

    <p>glucose</p> Signup and view all the answers

    Match the following conditions or defects with their effects:

    <p>Celiac disease = Global malabsorption Hartnup's disease = Neutral amino acid transport defect Enterokinase deficiency = Selective malabsorption IBS = Acquired lactase deficiency</p> Signup and view all the answers

    Which of the following is the hallmark symptom of malabsorption?

    <p>Steatorrhea</p> Signup and view all the answers

    The 72-hour fecal fat test is a qualitative measure of fat excretion in stools.

    <p>False</p> Signup and view all the answers

    What is defined as diminished intestinal digestion and absorption of one or more nutrients?

    <p>Malabsorption</p> Signup and view all the answers

    Passing of pale, bulky, fatty, malodorous, greasy stools is known as __________.

    <p>steatorrhea</p> Signup and view all the answers

    Match the following investigations with their descriptions:

    <p>72-hour fecal fat test = Gold standard for diagnosing steatorrhea Sudan III = Qualitative stool fat test Sudan IV = Identifies fat in stool Oilred O = A dye used to stain fat in feces</p> Signup and view all the answers

    What is the primary site for maximum nutrient absorption in the small intestine?

    <p>Jejunum</p> Signup and view all the answers

    The distal part of the small intestine primarily absorbs bile acid and Vitamin B2.

    <p>True</p> Signup and view all the answers

    What type of cells surround the villi in the small intestine?

    <p>Enterocytes</p> Signup and view all the answers

    The continuous renewal of the mucosal layer in the small intestine occurs every _____ hours.

    <p>48-72</p> Signup and view all the answers

    Match the following cells in the small intestine with their functions:

    <p>Goblet cells = Produce mucus for lubrication Paneth cells = Produce immunological substances Enteroendocrine cells = Secrete hormones Enterocytes = Absorb nutrients</p> Signup and view all the answers

    What is primarily affected in chronic pancreatitis?

    <p>Pancreatic lipase</p> Signup and view all the answers

    Bile acid defects can include issues with synthesis and early deconjugation in the small intestine.

    <p>True</p> Signup and view all the answers

    Name one condition associated with defects in small intestinal mucosal integrity.

    <p>Celiac disease</p> Signup and view all the answers

    In the post-mucosal phase of absorption, long-chain fatty acids are transported via intestinal lymphatics to form _______.

    <p>chylomicrons</p> Signup and view all the answers

    Which enzyme is responsible for breaking down lactose?

    <p>Lactase</p> Signup and view all the answers

    Match the conditions to their associated defects in absorption:

    <p>Chronic Pancreatitis = Defect in pancreatic lipase Bile Acid Defect = Defect in bile synthesis Celiac Disease = Defect in small intestinal mucosal integrity SIBO = Defect in secretion</p> Signup and view all the answers

    The primary transport mechanism for glucose and galactose in the gut is facilitated diffusion.

    <p>False</p> Signup and view all the answers

    Name the condition caused by a defect in SGLT1.

    <p>Familial glucose-galactose malabsorption syndrome</p> Signup and view all the answers

    The enzyme ________ breaks down sucrose into glucose and fructose.

    <p>sucrase</p> Signup and view all the answers

    Match the following carbohydrate absorption mechanisms with their corresponding transporters:

    <p>Glucose = GLUT2 Fructose = GLUT5 Glucose and Galactose = SGLT1 Glucose in the liver = Glucokinase</p> Signup and view all the answers

    Study Notes

    Approach to Diarrhea

    • Diarrhea is defined as stool water content > 200mL/24hrs
    • Diarrhea is classified by duration: <2 weeks (Infection), >4 weeks (Small bowel, Large bowel)
    • The Bristol stool chart is used to classify consistency: Types 1 & 2 are constipation, Types 6 & 7 are diarrhea
    • The most common causes of acute diarrhea are viral infections
    • Norovirus is the most common cause of acute diarrhea in adults
    • Rotavirus is the most common cause of acute diarrhea in children

    Small Intestinal vs Large Intestinal Diarrhea

    • Small intestinal diarrhea usually has large volume, watery consistency, absent pus/blood/mucus, present abdominal cramps and bloating
    • Large intestinal diarrhea usually has present pus/blood/mucus, present tenesmus, present dyschezia, present abdominal pain and fever
    • Small intestinal diarrhea is caused by osmotic, secretory, and vibrio cholera etiologies
    • Large intestinal diarrhea is caused by invasive organisms, e.g. Shigella, and inflammation, e.g. Ulcerative colitis
    • The stool osmotic gap is normal/decreased in secretory diarrhea and increased in osmotic diarrhea

    Layers of the Intestinal Wall

    • The submucosa contains Brunner's glands which secrete bicarbonate
    • The submucosa contains Peyer's patches, which are macroscopic lymphoid aggregates that hypertrophy in typhoid
    • The muscularis propria is a layer of muscle
    • The serosa is the outer layer of the intestinal wall
    • The small intestine is the site of the majority of absorption
    • The small intestine is divided into a proximal 2/5 and a distal 3/5
    • The proximal small intestine (jejunum > duodenum) is the site of maximum absorption
    • The distal small intestine (ileum) is the site of bile acid, vitamin B12, and magnesium absorption

    Fat Absorption

    • The luminal phase of fat absorption involves the breakdown of triglycerides by pancreatic lipase
    • The breakdown products of triglycerides combine with bile acids to form micelles
    • Micelles diffuse into enterocytes
    • Bile acids have an enterohepatic circulation, in which they are synthesized, conjugated, recycled
    • The rate-limiting enzyme of bile acid synthesis is 7a-hydroxylase
    • Bile acid synthesis in the liver is controlled by a negative feedback mechanism
    • Chronic pancreatitis can cause a bile acid defect
    • Bile acids play a role in the absorption of lipid soluble vitamins

    Protein Absorption

    • Endopeptidases like trypsin and exopeptidases like carboxypeptidase and aminopeptidase are involved in protein digestion
    • Enterokinase activates trypsinogen to trypsin
    • Transport of amino acids across the small intestinal mucosa occurs via sodium-amino acid co-transporters

    Defects in Protein Absorption

    • Global malabsorption can occur due to celiac disease, Whipple disease, and tropical sprue
    • Selective malabsorption can occur due to enterokinase deficiency, Hartnup's disease, and cystinuria
    • Enterokinase deficiency impairs the activation of trypsinogen to trypsin
    • Hartnup's disease causes a neutral amino acid transport defect
    • Cystinuria causes a dibasic amino acid transport defect, leading to excretion of cystine, ornithine, lysine, and arginine

    Carbohydrate Absorption

    • Disaccharidases in the small intestinal brush border epithelium break down disaccharides into monosaccharides
    • Lactase breaks down lactose into glucose and galactose
    • Maltase breaks down maltose into two glucose molecules
    • Sucrase breaks down sucrose into glucose and fructose
    • Trehalase breaks down trehalose into two glucose molecules
    • Sodium-glucose cotransporter 1 (SGLT1) is responsible for the active transport of glucose and galactose
    • Glucose transporter (GLUT2) facilitates the diffusion of glucose and galactose into the blood
    • Glucose is converted into glucose-6-phosphate by glucokinase in the liver
    • Fructose and galactose are phosphorylated in the liver
    • Fructose is transported across the intestinal mucosa by Glucose transporter (GLUT5)

    Defects in Carbohydrate Absorption

    • Lactase deficiency can be congenital or acquired (primary or secondary)
    • Congenital lactase deficiency is autosomal recessive
    • Acquired lactase deficiency is more common and caused by a genetic defect
    • Secondary lactase deficiency can occur due to infections and irritable bowel syndrome
    • Defects in the small intestinal mucosa can cause global carbohydrate malabsorption
    • Familial glucose-galactose malabsorption syndrome is caused by a defect in SGLT-1

    Chronic Diarrhea

    • Osmotic diarrhea is commonly caused by malabsorption of water, but osmotic diarrhea is also related to tumors and toxins
    • Secretory diarrhea is caused by an increase in fluid secretion into the intestinal lumen
    • Inflammatory diarrhea is caused by inflammatory bowel disease

    Pathological Classification of Diarrhea

    • Osmotic diarrhea is the most consistent clinical symptom of malabsorption
    • Steatorrhea is the hallmark of malabsorption, and it is the passing of pale, bulky, fatty, malodorous, greasy stools
    • Steatorrhea causes a decreased fat absorption in the small intestine, an increased stool osmolality in the colon
    • Steatorrhea causes stool to draw water from large intestinal epithelial cells
    • The gold standard for investigating steatorrhea is the 72-hour fecal fat test
    • The 72-hour fecal fat test involves fat input of 100 g/day. Stool fat excretion ≥7% is considered steatorrhea
    • Other tests for steatorrhea include qualitative stool fat tests using Sudan III, Sudan IV, or Oilred O

    Physiology of GIT Absorption and Selective Malabsorption

    • Absorption is divided into luminal, mucosal, and post mucosal stages
    • Luminal absorption involves enzyme-mediated processes in the small intestinal mucosa
    • The small intestinal mucosa is lined with enterocytes, villi, and crypts
    • Villi are surrounded by crypts of Lieberkuhn and contain brush borders with enzymes
    • Crypts contain Paneth cells, enteroendocrine cells, and goblet cells
    • The small intestinal mucosa is continuously renewed every 48-72 hours
    • The lamina propria contains glands and blood vessels
    • The muscularis mucosa provides a tight attachment to the mucosa
    • Plicae circulares are visible mucosal folds on the luminal surface of the small intestine
    • The interstitial cells of Cajal are pacemaker cells of the small intestine
    • The small intestine has a basal electrical rhythm

    Defects in Luminal Absorption

    • Chronic pancreatitis affects pancreatic lipase, which leads to impaired lipolysis
    • Bile acid defects occur due to defects in synthesis or premature deconjugation in the small intestine
    • Defects in reabsorption can occur in tuberculosis and Crohn's disease
    • Defects in secretion can occur in primary biliary cholangitis, primary sclerosing cholangitis, and small intestinal bacterial overgrowth (SIBO)

    Mucosal Phase of Absorption

    • Defects in the small intestinal mucosal integrity can cause malabsorption
    • Celiac disease, Whipple disease, and tropical sprue can impair mucosal absorption

    Post-Mucosal Phase of Absorption

    • Long-chain fatty acids (LCFA) are esterified and transported via intestinal lymphatics to form chylomicrons

    Types of Fatty Acids

    • Long-chain fatty acids (LCFA) have a carbon chain length > 12
    • Medium-chain fatty acids (MCFA) have a carbon chain length of 8-12
    • Short-chain fatty acids (SCFA) have a carbon chain length of < 8

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the definitions, classifications, and key causes of diarrhea, including acute viral infections. It distinguishes between small and large intestinal diarrhea based on characteristics and causes, providing a comprehensive overview of this common medical issue.

    More Like This

    Diarrhea Classification Quiz
    4 questions

    Diarrhea Classification Quiz

    AgreeableEnlightenment7879 avatar
    AgreeableEnlightenment7879
    Diarrhea Classification and Causes
    82 questions

    Diarrhea Classification and Causes

    AdvantageousCarnelian858 avatar
    AdvantageousCarnelian858
    Assessing and Classifying Diarrhea
    19 questions

    Assessing and Classifying Diarrhea

    HandsomeVariable avatar
    HandsomeVariable
    Pathology: Gastrointestinal Tract
    141 questions

    Pathology: Gastrointestinal Tract

    GlowingDada4940 avatar
    GlowingDada4940
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser