Gastrointestinal Tract Functions Quiz
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Questions and Answers

What is the primary purpose of the housekeeper wave in the gastrointestinal tract?

  • To promote digestion
  • To stimulate appetite
  • To clean the GIT of undigested materials (correct)
  • To absorb nutrients

    • Peristalsis is a voluntary movement of the gastrointestinal tract.

    False

    Name one neurotransmitter involved in the peristalsis process.

    Acetylcholine

    The portion of the GIT that moves food from the proximal to the distal region is called the ______.

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

    Match the following terms with their definitions:

    <p>Peristalsis = Involuntary contraction and relaxation of smooth muscles Housekeeper wave = Cleans GIT of undigested materials Acetylcholine = Stimulates muscle contraction in GIT Vasoactive intestinal peptides = Facilitates relaxation below food bolus</p> Signup and view all the answers

    Which nerve is associated with the sensory and motor functions of the mandible?

    <p>Trigeminal nerve</p> Signup and view all the answers

    The GIT can store foodstuff in its current location.

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

    What major activity is associated with gastrin?

    <p>Stimulates pepsinogen secretion</p> Signup and view all the answers

    Somatostatin is released from the G cells located in the stomach.

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

    Which stimuli trigger the release of gastrin?

    <p>Distension, vagal stimulation, peptides, amino acids</p> Signup and view all the answers

    Somatostatin inhibits _______ and HCl release.

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

    Match the gastrointestinal hormone to its location:

    <p>Gastrin = G cells in the antrum of the stomach Somatostatin = D cells in the antrum of the stomach Insulin = Pancreatic islets Cholecystokinin = Small intestine</p> Signup and view all the answers

    Where is somatostatin primarily secreted?

    <p>D cells</p> Signup and view all the answers

    What effect does somatostatin have on gastric secretions?

    <p>It inhibits gastric secretions.</p> Signup and view all the answers

    Amino acids can stimulate the release of gastrin.

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

    Gastrin is primarily involved in the secretion of ____________ and pepsinogen.

    <p>gastric acid</p> Signup and view all the answers

    What hormone is primarily believed to mediate hunger in fasting states?

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

    Gastrin is released from the stomach in response to food and stimulates the secretion of gastric juice.

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

    Name the phase characterized by the release of intestinal gastrin from intestinal cells.

    <p>Intestinal Phase</p> Signup and view all the answers

    The ___________ complex is triggered by motility and stimulates gastric juice secretion.

    <p>migrating motor</p> Signup and view all the answers

    Which hormone is secreted during the postprandial state?

    <p>Gastrin-Releasing Peptide</p> Signup and view all the answers

    The vagal stimulation primarily affects only the small intestine.

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

    What triggers the release of most GI hormones after eating?

    <p>Food in the stomach</p> Signup and view all the answers

    __________ is released from the stomach and stimulates the gastric phase.

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

    Match the following hormones to their respective roles:

    <p>Motilin = Stimulates motility and gastric juice secretion Ghrelin = Mediates hunger during fasting Gastrin = Stimulates gastric juice production Gastrin-Releasing Peptide = Promotes secretion of gastric juice after eating</p> Signup and view all the answers

    Which phase involves reflex responses that stimulate gastric juice secretion?

    <p>Gastric Phase</p> Signup and view all the answers

    What is the main secretory product of Chief cells in the gastric gland?

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

    Parietal cells secrete HCl and intrinsic factor.

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

    What is the secretory product of G cells?

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

    The surface mucous cells secrete mucin in an __________ fluid.

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

    Match the gastric gland cells with their secretory products:

    <p>Surface mucous cells = Mucin in an alkaline fluid Mucous neck cells = Mucin in an acidic fluid Parietal cells = HCl and intrinsic factor Chief cells = Pepsinogen and lipase</p> Signup and view all the answers

    Which cells are responsible for secreting intrinsic factor?

    <p>Parietal cells</p> Signup and view all the answers

    Acetylcholine is a secretory product of Chief cells.

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

    What is the role of secretin in the digestive system?

    <p>Regulates water and bicarbonate secretion</p> Signup and view all the answers

    The secretion of __________ stimulates the intestinal secretion of water and electrolytes.

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

    What is the primary secretion of mucous neck cells?

    <p>Mucin in an acidic fluid</p> Signup and view all the answers

    Tonic contractions are characterized by sustained amounts of calcium, leading to continuous contractions even in the absence of external stimuli.

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

    What is the primary function of tonic contractions in sphincters?

    <p>To prevent the backward movement of bolus.</p> Signup and view all the answers

    Which of the following is NOT a characteristic of phasic contractions?

    <p>Sustained continuous contractions</p> Signup and view all the answers

    Phasic contractions are responsible for the ______ movements that propel food through the digestive tract.

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

    Match the following terms with their corresponding descriptions:

    <p>Tonic Contractions = Sustained contractions in the absence of external stimuli Phasic Contractions = Rhythmic contractions occurring at specific frequencies Sphincters = Circular muscles that control the passage of substances Peristalsis = Wave-like muscular contractions that move food through the digestive tract</p> Signup and view all the answers

    Which of the following arteries is NOT involved in the arterial supply of the gastrointestinal tract?

    <p>Femoral artery</p> Signup and view all the answers

    What is the primary purpose of the celiac artery in the GI tract?

    <p>The celiac artery supplies blood to the stomach, liver, and spleen.</p> Signup and view all the answers

    The hepatic arteries exclusively supply blood to the liver.

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

    The arterial supply of the gastrointestinal tract is essential for providing ______ and ______ to the digestive organs.

    Signup and view all the answers

    Which of the following is NOT a potential result of this deficiency?

    <p>Increased blood pressure</p> Signup and view all the answers

    Gastrulation of the gastrointestinal tract occurs between the 3rd and 32nd weeks of gestation.

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

    What is a condition where a portion of the gastrointestinal tract is closed or absent?

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

    Meconium Ileus occurs when the first stool blocks the last part of the baby's ______.

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

    Match the following embryological defects with their descriptions:

    <p>Esophageal Atresia = Esophagus is closed or absent Pyloric Stenosis = Narrowing of the pylorus Omphalocele = Abdominal contents protrude outside abdomen Meconium Ileus = First stool blocks the intestine</p> Signup and view all the answers

    Which germ layer of the gastrointestinal tract is responsible for muscle and connective tissue development?

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

    Hypertrophy/Pyloric Stenosis involves the failure of the tract to develop.

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

    What characterizes radiating pain?

    <p>Pain that spreads from one area to another</p> Signup and view all the answers

    Referred pain presents as somatic pain confined to a well-defined location.

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

    What is the primary difference between referred pain and radiating pain?

    <p>Referred pain is localized while radiating pain spreads to other areas.</p> Signup and view all the answers

    Pain that initially is confined to a small area but then spreads is called __________ pain.

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

    Match the following types of pain with their descriptions:

    <p>Referred Pain = Presents as somatic pain, may not have well-defined location Radiating Pain = Pain that spreads from one area to another Somatic Pain = Pain that originates from skin, muscles, and joints Autonomic Pain = Pain associated with internal organs affecting autonomic functions</p> Signup and view all the answers

    Which of the following is a characteristic of tonic contractions?

    <p>They are sustained contractions that occur even in the absence of stimuli.</p> Signup and view all the answers

    Phasic contractions are observed in smooth muscles and sphincters.

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

    _________ contractions are rhythmic contractions that occur at intrinsic frequencies and are typically short-lived.

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

    Match the following types of contractions with their descriptions:

    <p>Tonic contractions = Sustained and continuous contractions in the absence of stimuli. Phasic contractions = Rhythmic contractions of short duration at intrinsic frequencies.</p> Signup and view all the answers

    What type of contractions are responsible for the peristaltic movements that propel food through the digestive tract?

    <p>Phasic contractions</p> Signup and view all the answers

    The celiac artery is involved in the arterial supply of the gastrointestinal tract.

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

    The arterial supply of the gastrointestinal tract provides ______ and ______ to the digestive organs.

    <p>oxygen, nutrients</p> Signup and view all the answers

    What is the duration of Phase 3 of the Myoelectric Complex?

    <p>10-20 min</p> Signup and view all the answers

    Phase 2 of the Myoelectric Complex involves only quiescent periods with no contractions.

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

    Name the muscle that primarily elevates the mandible.

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

    Phase 1 is characterized by a quiescent period with __________ contractions.

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

    Match the phases of the Myoelectric Complex with their characteristics:

    <p>Phase 1 = Quiescent period with rare contractions Phase 2 = Intermittent contractions that increase in intensity Phase 3 = Short periods of intense, large contractions</p> Signup and view all the answers

    Which division of the Trigeminal nerve is primarily involved in closing the mouth?

    <p>Mandibular Division</p> Signup and view all the answers

    The Angle and surface of the ramus of the mandible are involved in elevating bone during Phase 3.

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

    What muscle action occurs in Phase 2 of the Myoelectric Complex?

    <p>Intermittent action potentials and contractions</p> Signup and view all the answers

    The __________ muscle is primarily responsible for retracting the mandible during the Myoelectric Complex.

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

    Which muscle is described by the terms 'medial pterygoid' and 'elevates and retracts mandible'?

    <p>Medial pterygoid</p> Signup and view all the answers

    What is the main function of the fundic area of the stomach?

    <p>To receive food from the esophagus</p> Signup and view all the answers

    The fundic area can accommodate a large portion of food without increasing pressure.

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

    What type of movement may occur in the stomach when the fundus is filled with food?

    <p>Peristaltic movement</p> Signup and view all the answers

    The _______ layer is an additional muscle layer unique to the stomach.

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

    Match the following terms with their corresponding functions in the stomach:

    <p>Fundus = Receives food from the esophagus Body = Mixes food with gastric secretions Pylorus = Controls food entry to the small intestine Cardia = Region where the esophagus opens into the stomach</p> Signup and view all the answers

    Which process is primarily responsible for mixing food in the stomach?

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

    The stomach is the only organ that contains an oblique muscle layer.

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

    What is the role of the lower esophageal sphincter?

    <p>To prevent food from entering the respiratory system</p> Signup and view all the answers

    The structures involved in swallowing include the _______ and esophagus.

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

    Match the stomach regions with their primary functions:

    <p>Fundus = Accommodates food Body = Digestive mixing Pyloric sphincter = Regulates food entry to the intestine Cardia = Entrance from the esophagus</p> Signup and view all the answers

    Study Notes

    Regulation of Energy Homeostasis

    • Systems of food intake regulation prevent overeating during meals.
    • Long-term regulation maintains energy stores (fat) by regulating food intake and energy balance via insulin and leptin.
    • Short-term regulation prevents overeating during each meal and involves signaling from the gastrointestinal tract (GIT) and the liver.

    Hunger and Appetite Hormones

    • Ghrelin and Leptin signal the hypothalamus to regulate appetite.
    • Ghrelin increases appetite, produced in the stomach.
    • Leptin decreases appetite, produced in adipose tissue.
    • Ghrelin levels rise when the stomach is empty, stimulating appetite, and fall when full.
    • Ghrelin is a 28-amino-acid peptide hormone, first described in 1999.
    • It stimulates the pituitary gland to release growth hormone.
    • Ghrelin is produced by endocrine cells lining the stomach and proximal small intestine, including P/D1 cells in the stomach fundus.
    • Ghrelin is associated with psychiatric conditions such as anorexia nervosa.
    • Leptin is a protein hormone made by adipocytes.
    • It sends signals to the hypothalamus to indicate satiety and boosts metabolism.
    • Leptin levels rise with increased adipose tissue size and communicate energy storage status.
    • Leptin levels show circadian fluctuations and change with nutritional intake.

    Gastrointestinal Tract (GIT)

    • Embryological development involves three germinal layers: Mesoderm, Ectoderm, and Endoderm.
    • Embryological defects include atresia (closed or absent orifices), hypertrophy/pyloric stenosis (thickening/narrowing of the pylorus), omphalocele (abdominal contents outside the abdominal cavity), esophageal atresia, duodenal atresia, and jejunal and ileal atresia.
    • Functional anatomy includes the mouth, esophagus, stomach, small intestine, large intestine and accessory organs (liver, pancreas, gallbladder).
    • Control mechanisms involve the nervous system (autonomic and enteric) and the endocrine system (hormones).
    • Accessory organs secrete substances for digestion and nutrient absorption.

    GIT Motility

    • Types of movements include peristalsis (propelling food), segmentation (mixing food), haustral contractions (mixing in large intestine), and mass movements (large intestine propulsion).
    • Tonic contractions are sustained, while phasic contractions are rhythmic and temporary.
    • Sphincters (gastroesophageal, pyloric, ileocecal, internal anal) regulate GIT area division.
    • Myenteric (Auerbach's) and submucosal (Meissner's) plexuses control GIT motility and secretions.
    • Migrating myoelectric complex (MMC) moves undigested materials during interdigestive periods.

    Stomach

    • The stomach stores and churns food, mixes it and refines the food into chyme, before allowing it to the small intestines
    • The stomach has three layers of muscles (circular, longitudinal, and oblique).
    • Oblique muscles are unique to the stomach for churning and mixing.

    Intestines

    • Small intestine: Completes digestion, absorbs nutrients and water, and has villi to increase surface area.
    • Large intestine: Reabsorbs water and ions, forms and stores feces.
    • Small and large intestines have different specialized layers for absorption and propulsion.
    • The intestinal layers include mucosa, submucosa, muscularis externa, and serosa.
    • Cells in the intestinal lining (enterocytes, goblet cells, enteroendocrine cells, Paneth cells).

    Control of Defecation

    • Intrinsic defecation reflex: Feces stimulate stretch receptors in the rectum triggers the relaxation of the internal anal sphincter.
    • Integrated defecation reflex involves parasympathetic stimulation.
    • Conscious control involves the external anal sphincter.

    Secretion in GIT

    • Salivary glands produce saliva to moisten and lubricate food.
    • Salivary glands produce amylase for starch digestion.
    • Gastric glands secrete HCl, pepsinogen (precursor of pepsin), intrinsic factor, and mucus.
    • Intestinal glands secrete various enzymes (e.g. peptidases, sucrase, lactase, maltase) and bicarbonate to aid digestion and absorption.
    • Different glands have different secretion types and consistencies.
    • Salivary glands produce different types of saliva with varying viscosity and mineral content.

    Bristol Stool Chart

    • A tool for describing stool consistency (types 1-7) for assessment of bowel health.
    • Viscous and solid stools are associated with constipation, while liquid stools with diarrhea.

    Nervous System Control

    • Autonomic nervous system(ANS): Sympathetic inhibits most GIT functions and parasympathetic stimulates most.
    • Enteric nervous system (ENS) is the intrinsic control mechanism in the tract.
    • CNS (central nervous system) control of reflexes (e.g. defecation).

    Additional information

    • Hormones (e.g., gastrin, secretin, GIP) regulate digestive secretions and motility.
    • GI tract histology details its layers (mucosa, submucosa, muscularis externa, serosa/adventitia) and specialized cells.
    • Autonomic and enteric nervous systems coordinate digestive functions.
    • Food types (fatty, etc.) affect release of hormones and contractions.
    • Stomach, intestines, and accessory organs have different secretions to complete digestion.

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    Description

    Test your knowledge on the functions and hormones of the gastrointestinal tract. This quiz covers key concepts including peristalsis, the role of gastrin, and the effects of somatostatin. Perfect for students studying gastrointestinal physiology or related fields.

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