Gastrointestinal Tract Function and Pathology
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Questions and Answers

What are common factors that can interfere with the normal function of the gastrointestinal tract?

  • Genetic predispositions
  • Excessive physical activity
  • Stress and anxiety (correct)
  • Bacterial infections

    • What is the approximate length of the gastrointestinal tract in meters?

  • 7 to 7.9 m (correct)
  • 8 to 9 m
  • 5 to 6 m
  • 10 to 11 m

    • Which part of the GI tract is primarily responsible for controlling the opening to the small intestine?

  • The pylorus (correct)
  • The body
  • The cardia
  • The fundus

    • Which of the following is NOT a type of pathology that can affect the gastrointestinal tract?

    <p>Respiratory distress</p> Signup and view all the answers

    What is the main function of the stomach in relation to digestion?

    <p>Storage of food and secretion of digestive fluids</p> Signup and view all the answers

    Which anatomical feature of the esophagus allows it to pass through the diaphragm?

    <p>Esophageal hiatus</p> Signup and view all the answers

    Which part of the GI tract is located under the left lobe of the liver?

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

    What typically occurs when there is faulty nervous system control in the gastrointestinal tract?

    <p>Motor disturbances leading to constipation or diarrhea</p> Signup and view all the answers

    What role does intrinsic factor play in vitamin B12 absorption?

    <p>It is essential for vitamin B12 absorption.</p> Signup and view all the answers

    What is the primary substance responsible for acidity in the stomach?

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

    Which of the following hormones or substances primarily influences gastric motility?

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

    What is the major function of the small intestine?

    <p>Absorption of nutrients</p> Signup and view all the answers

    Which digestive enzyme is responsible for protein digestion in the pancreas?

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

    How long does chyme typically remain in the small intestine?

    <p>3 to 6 hours</p> Signup and view all the answers

    What is the sphincter called that controls bile flow from the common bile duct into the duodenum?

    <p>Sphincter of Oddi</p> Signup and view all the answers

    What type of contractions in the small intestine are responsible for mixing the contents?

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

    Which mineral is absorbed throughout the length of the small intestine?

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

    What is the primary component of feces?

    <p>Undigested foodstuffs</p> Signup and view all the answers

    What is the primary purpose of colonic secretions?

    <p>To protect the colonic mucosa</p> Signup and view all the answers

    Which part of the small intestine is primarily responsible for bile salts absorption?

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

    What function does the ileocecal valve serve?

    <p>Controlling the passage of waste to the colon</p> Signup and view all the answers

    What is the process by which fats are made easier to absorb?

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

    What primarily contributes to the brown color of feces?

    <p>Bile breakdown by intestinal bacteria</p> Signup and view all the answers

    Which gas is NOT typically formed in the gastrointestinal tract?

    <p>Nitrous oxide</p> Signup and view all the answers

    Which structure's contraction facilitates the elimination of stool?

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

    The gut microbiota begins to colonize the gastrointestinal tract shortly after which event?

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

    Which of the following factors does NOT affect the composition of normal gut microbiota?

    <p>Weather conditions</p> Signup and view all the answers

    What role does the gut microbiome play in immune function?

    <p>Provoking an immune response</p> Signup and view all the answers

    What is the primary control mechanism for the internal anal sphincter?

    <p>Parasympathetic nervous system</p> Signup and view all the answers

    Which of the following symptoms is commonly associated with dyspepsia?

    <p>Upper abdominal discomfort</p> Signup and view all the answers

    What happens to the external anal sphincter during defecation?

    <p>It voluntarily relaxes</p> Signup and view all the answers

    How does aging primarily affect the gastrointestinal system?

    <p>Has minimal direct effect on GI functions</p> Signup and view all the answers

    What type of pain is most commonly associated with gastrointestinal diseases?

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

    What is the primary action required immediately after excising tissue?

    <p>Place in moist gauze or appropriate receptacle and label correctly</p> Signup and view all the answers

    Which of the following is NOT typically necessary before a bowel examination?

    <p>Dietary restrictions</p> Signup and view all the answers

    What is a common trigger for dyspepsia symptoms?

    <p>Fatty foods</p> Signup and view all the answers

    During a small bowel procedure, what vital sign aspect would a nurse monitor?

    <p>Skin color and temperature</p> Signup and view all the answers

    What is the role of Peyer's patches in the gastrointestinal tract?

    <p>Antigen processing and immune defense</p> Signup and view all the answers

    What should a nurse monitor the patient for after a bowel examination?

    <p>Signs of intestinal perforation</p> Signup and view all the answers

    Which of the following methods is used for visualization of the small intestine?

    <p>Capsule endoscopy</p> Signup and view all the answers

    What is the main purpose of the hydrogen breath test?

    <p>To evaluate carbohydrate absorption</p> Signup and view all the answers

    Which test is recommended by the ACS for cancer screening?

    <p>Fecal immunochemical test (FIT)</p> Signup and view all the answers

    What should patients avoid before undergoing urea breath testing?

    <p>Taking antibiotics</p> Signup and view all the answers

    What type of imaging does endoscopic ultrasonography (EUS) provide?

    <p>Direct imaging through the gastrointestinal tract</p> Signup and view all the answers

    How often should the FIT-fecal DNA test be performed according to the recommendations?

    <p>Every 3 years</p> Signup and view all the answers

    Which of the following is NOT a typical use of abdominal ultrasonography?

    <p>Examining bone density</p> Signup and view all the answers

    What is the requirement for dietary restrictions before collecting a stool specimen for a FIT test?

    <p>No dietary restrictions necessary</p> Signup and view all the answers

    What is a key advantage of using abdominal ultrasonography?

    <p>Provides immediate results</p> Signup and view all the answers

    Which of the following genetic conditions is associated with Lynch syndrome?

    <p>Colon cancer</p> Signup and view all the answers

    What is a limitation of abdominal ultrasonography?

    <p>Operator experience is crucial</p> Signup and view all the answers

    How should a patient prepare for gallbladder studies involving ultrasonography?

    <p>Fast for 12 to 24 hours</p> Signup and view all the answers

    What is the protocol for genetic counseling for at-risk individuals?

    <p>Education on disease prevention and treatment options</p> Signup and view all the answers

    What is normally observed in the buccal mucosa during an examination?

    <p>A small red dot indicating the Stensen duct</p> Signup and view all the answers

    What findings on the dorsum of the tongue would be considered normal?

    <p>Thin white coat and large vallate papillae in a 'V' formation</p> Signup and view all the answers

    What is detected by the urea breath test?

    <p>Presence of Helicobacter pylori</p> Signup and view all the answers

    What does an asymmetric rise of the uvula during the phonation of 'ah' indicate?

    <p>Possible neurological impairment</p> Signup and view all the answers

    Which method is employed to auscultate bowel sounds?

    <p>With the diaphragm of the stethoscope</p> Signup and view all the answers

    How is rebound tenderness usually evaluated during an abdominal examination?

    <p>Light percussion is used instead due to pain considerations</p> Signup and view all the answers

    Which part of the assessment evaluates the rectum and perianal region?

    <p>Rectal inspection and palpation</p> Signup and view all the answers

    What should be done if bowel sounds are absent after a minimum of 5 minutes of auscultation?

    <p>Reassess bowel sounds after additional 5 minutes</p> Signup and view all the answers

    What differentiates gastro-esophageal reflux disease (GERD) from gastro-esophageal reflux (GER)?

    <p>GERD is the more serious and longer-lasting condition.</p> Signup and view all the answers

    What could the presence of white or red plaques in the oral cavity suggest?

    <p>Oral cancer or lesions</p> Signup and view all the answers

    What is the importance of inspecting the gums during an oral assessment?

    <p>To identify systemic diseases and inflammation</p> Signup and view all the answers

    Which of the following symptoms is commonly associated with excessive flatulence?

    <p>Bloating and distention</p> Signup and view all the answers

    During the inspection of the abdomen, what is the first step to be performed?

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

    Nausea can commonly be triggered by which of the following?

    <p>Odors and food intake</p> Signup and view all the answers

    What is the typical sound associated with air in the stomach during percussion?

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

    What condition is characterized by the forceful emptying of gastric contents through the mouth?

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

    What does a flat abdominal contour generally indicate?

    <p>Normal anatomical positioning</p> Signup and view all the answers

    Which type of stool is likely to indicate bleeding in the upper gastrointestinal tract?

    <p>Tarry-black stool (melena)</p> Signup and view all the answers

    What is considered an abnormal increase in stool frequency or liquidity?

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

    Which cranial nerve is assessed by evaluating the tongue's symmetry and strength?

    <p>Hypoglossal nerve (12th cranial nerve)</p> Signup and view all the answers

    What symptom might accompany constipation?

    <p>Anal discomfort</p> Signup and view all the answers

    What may lead to a change in stool characteristics?

    <p>Specific disease processes or certain foods</p> Signup and view all the answers

    What could indicate a Mallory-Weiss tear during vomiting?

    <p>Bright red or coffee ground appearance in emesis</p> Signup and view all the answers

    Which of the following could be a reason for a health care provider to inquire about a patient’s dietary habits?

    <p>Identifying potential food intolerances</p> Signup and view all the answers

    What is the primary function of the ileocecal valve?

    <p>To prevent reflux of bacteria into the small intestine</p> Signup and view all the answers

    The assessment of which area is important during a physical examination of the gastrointestinal system?

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

    What common dietary symptom might indicate gallbladder disease?

    <p>Excessive flatulence</p> Signup and view all the answers

    Which part of the gastrointestinal tract primarily absorbs nutrients?

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

    What role does salivary amylase play in digestion?

    <p>It starts the digestion of starches</p> Signup and view all the answers

    What should be inspected in a patient during an oral cavity examination?

    <p>Lips’ color, texture, and hydration</p> Signup and view all the answers

    Which structure prevents food from entering the trachea during swallowing?

    <p>The epiglottis</p> Signup and view all the answers

    What is not a typical characteristic of normally formed stool?

    <p>Greasy and foamy consistency</p> Signup and view all the answers

    What is the pH level of the gastric fluid secreted in the stomach?

    <p>As low as 1</p> Signup and view all the answers

    Which blood vessels are primarily responsible for supplying oxygen and nutrients to the intestine?

    <p>Superior and inferior mesenteric arteries</p> Signup and view all the answers

    Which function is NOT associated with the gastrointestinal tract?

    <p>Production of hormones</p> Signup and view all the answers

    What is the role of pepsin in the stomach?

    <p>To aid in protein digestion</p> Signup and view all the answers

    Which of the following statements about the GI tract is correct?

    <p>The GI tract is innervated by both sympathetic and parasympathetic nerves.</p> Signup and view all the answers

    What type of muscle forms the internal and external anal sphincters?

    <p>Striated muscle</p> Signup and view all the answers

    Which section of the small intestine is responsible for the bulk of nutrient absorption?

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

    What is the primary digestive function of the stomach's acidic secretions?

    <p>To break down food particles and kill bacteria</p> Signup and view all the answers

    What initiates peristalsis in the esophagus?

    <p>The swallowing reflex</p> Signup and view all the answers

    What is the approximate length of the small intestine?

    <p>70 feet</p> Signup and view all the answers

    Which of the following veins contribute to the portal venous system?

    <p>Superior mesenteric and cystic veins</p> Signup and view all the answers

    What is the recommended position for performing a rectal examination that many patients find comfortable?

    <p>Lying on the right side with knees drawn up</p> Signup and view all the answers

    What should the examiner observe for during the external examination of the rectal area?

    <p>Presence of lumps, rashes, or inflammation</p> Signup and view all the answers

    What physical response indicates that additional rectal abnormalities may be visible during an examination?

    <p>The patient bears down</p> Signup and view all the answers

    What is a key nursing intervention for patients undergoing GI diagnostic evaluation?

    <p>Assessing hydration before, during, and after the procedure</p> Signup and view all the answers

    What kind of tests are commonly performed as initial serum laboratory studies?

    <p>Complete blood count and liver function tests</p> Signup and view all the answers

    What characteristics are assessed during the inspection of stool specimens?

    <p>Consistency, color, and presence of occult blood</p> Signup and view all the answers

    What dietary restrictions should patients follow before undergoing guaiac-based fecal occult blood testing?

    <p>Avoiding red meats and vitamin C-rich foods</p> Signup and view all the answers

    What is indicated when carcinoembryonic antigen (CEA) is detected in blood tests?

    <p>Presence of cancer, but not type</p> Signup and view all the answers

    Which condition can both tenderness and inflammation in the rectal area suggest?

    <p>Pilonidal cyst or anal abscess</p> Signup and view all the answers

    Why are bowel preparations particularly challenging for older adults during GI evaluations?

    <p>They can significantly alter fluid and electrolyte balance</p> Signup and view all the answers

    What sort of stool studies require laboratory evaluation beyond basic inspection?

    <p>Fecal leukocytes and parasites testing</p> Signup and view all the answers

    How should stool samples be handled for quantitative studies?

    <p>Refrigerated until transported to the laboratory</p> Signup and view all the answers

    What type of behaviors might be recommended for a patient during an internal examination to reduce discomfort?

    <p>Practicing deep breathing and visualization</p> Signup and view all the answers

    What is the role of tumor markers like CA 19-9 in cancer management?

    <p>They are used to follow the effectiveness of treatment</p> Signup and view all the answers

    What is a necessary preparation step for a patient scheduled to undergo a barium enema?

    <p>Cleansing enemas until returns are clear</p> Signup and view all the answers

    What condition contraindicates the use of barium enemas?

    <p>Active inflammatory disease of the colon</p> Signup and view all the answers

    How can post-procedural complications from an IV contrast agent be minimized?

    <p>Maintaining hydration status</p> Signup and view all the answers

    What is a primary use of Magnetic Resonance Imaging (MRI) in gastroenterology?

    <p>Evaluating abdominal soft tissues</p> Signup and view all the answers

    What is a risk associated with the use of IV contrast agents during imaging studies?

    <p>Allergic reactions</p> Signup and view all the answers

    What is an essential patient preparation step before an MRI?

    <p>Removing all jewelry and metals</p> Signup and view all the answers

    Why are barium enemas scheduled before any upper gastrointestinal studies?

    <p>To ensure accurate results for the procedure</p> Signup and view all the answers

    Which statement is true regarding the CT scan procedure?

    <p>The procedure is completely painless</p> Signup and view all the answers

    Which of the following is NOT a reason for performing a CT scan?

    <p>Assessing bone density</p> Signup and view all the answers

    What is a common fear that patients may experience during an MRI?

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

    What is the effect of barium's high osmolarity in the gastrointestinal tract?

    <p>It may draw fluid into the bowel</p> Signup and view all the answers

    What common side effect might some patients experience after receiving a contrast agent?

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

    Which of the following describes the process of obtaining CT images?

    <p>Images are captured from multiple angles and then reconstructed</p> Signup and view all the answers

    What is the main purpose of PET scans in diagnostic imaging?

    <p>Evaluating physiological functions and metabolic processes</p> Signup and view all the answers

    What is the purpose of administering midazolam before a procedure?

    <p>To provide moderate sedation and relieve anxiety</p> Signup and view all the answers

    What is a common disadvantage of virtual colonoscopy?

    <p>Need for bowel preparation</p> Signup and view all the answers

    During gastroscopy, what monitoring is done post-procedure?

    <p>Vital signs, level of consciousness, and oxygen saturation</p> Signup and view all the answers

    What is one of the goals of colonoscopic polypectomy?

    <p>To prevent colorectal cancer</p> Signup and view all the answers

    In which position is the patient typically placed during a colonoscopy?

    <p>Left lateral position</p> Signup and view all the answers

    What is the purpose of administering atropine during endoscopic procedures?

    <p>To reduce secretions</p> Signup and view all the answers

    What complication can occur from medications given during colonoscopy?

    <p>Cardiac arrhythmias</p> Signup and view all the answers

    What is the main goal of bowel decompression during colonoscopy?

    <p>To prevent gas and fluid distension</p> Signup and view all the answers

    What does capsule colonoscopy involve?

    <p>Ingesting a capsule with a camera</p> Signup and view all the answers

    Which method is commonly used for effective cleansing of the bowel prior to colonoscopy?

    <p>PEG electrolyte lavage solutions</p> Signup and view all the answers

    What is a key consideration for patients after undergoing moderate sedation?

    <p>They should remain in bed until fully alert</p> Signup and view all the answers

    What is often monitored continuously during a colonoscopy?

    <p>Cardiac and respiratory function</p> Signup and view all the answers

    Why might a patient need a follow-up colonoscopy after capsule colonoscopy?

    <p>If the capsule test is positive</p> Signup and view all the answers

    What does the use of biopsies during colonoscopy achieve?

    <p>Helps in diagnosing potential cancers</p> Signup and view all the answers

    What is the primary purpose of an upper gastrointestinal (GI) series?

    <p>To visualize anatomic and functional disorders of the upper GI organs</p> Signup and view all the answers

    What is a common contrast agent used in an upper GI fluoroscopy?

    <p>Diatrizoate sodium (Hypaque)</p> Signup and view all the answers

    What is the purpose of the double-contrast method in an upper GI study?

    <p>To provide finer detail and detect early superficial neoplasms</p> Signup and view all the answers

    How long can the enteroclysis procedure take, even during normal motility?

    <p>Up to 6 hours</p> Signup and view all the answers

    What is recommended for patients regarding dietary changes prior to an upper GI study?

    <p>A low residue or clear liquid diet</p> Signup and view all the answers

    What is the purpose of using a barium enema during a lower GI study?

    <p>To detect abnormalities in the large intestine</p> Signup and view all the answers

    Which of the following is NOT considered a nursing intervention prior to an upper GI study?

    <p>Advising the patient to smoke to relieve anxiety</p> Signup and view all the answers

    What type of imaging technique has largely replaced the need for double-contrast barium enemas?

    <p>CT colonography</p> Signup and view all the answers

    What adverse effect may a patient experience during a double-contrast barium enema?

    <p>Cramping or discomfort</p> Signup and view all the answers

    Which bowel-cleansing agent is considered most effective?

    <p>Polyethylene glycol (PEG)-based solutions</p> Signup and view all the answers

    What is the main benefit of using methylcellulose during enteroclysis?

    <p>It provides enhanced visibility in imaging</p> Signup and view all the answers

    When is a water-soluble iodinated contrast agent used instead of barium for imaging?

    <p>When active disease or perforation is suspected</p> Signup and view all the answers

    Which imaging modality is used to assess lesions or adhesions after an upper GI study?

    <p>CT scan</p> Signup and view all the answers

    What radioactive isotopes are commonly used in scintigraphy?

    <p>Technetium, iodine, indium</p> Signup and view all the answers

    During gastric emptying studies, which meal component is tagged with radionuclide markers?

    <p>Scrambled eggs</p> Signup and view all the answers

    What is the purpose of tagging red blood cells in scintigraphic studies?

    <p>To define areas of inflammation or neoplasm</p> Signup and view all the answers

    What is the recommended diet for patients prior to undergoing bowel preparation?

    <p>Clear liquid or low residue diet</p> Signup and view all the answers

    How are colonic transit studies conducted?

    <p>By swallowing a capsule containing radionuclide markers</p> Signup and view all the answers

    Which patient condition would contraindicate the use of lavage solutions for bowel preparation?

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

    What dosage of sodium phosphate tablets is recommended for colon cleansing?

    <p>32 tablets</p> Signup and view all the answers

    What does the use of electronic video endoscopes allow during an upper GI fibroscopy?

    <p>Recording of the procedure for future reference</p> Signup and view all the answers

    What is the expected duration for a patient to pass radionuclide markers in colonic transit studies?

    <p>4 to 5 days</p> Signup and view all the answers

    Which side effects are commonly associated with electrolyte solutions used in bowel preparation?

    <p>Nausea, bloating, and cramps</p> Signup and view all the answers

    What is important to monitor in older patients following a bowel preparation?

    <p>Physiologic ability to compensate for fluid loss</p> Signup and view all the answers

    What is a common indication for performing an endoscopic retrograde cholangiopancreatography (ERCP)?

    <p>Evaluation of jaundice and pancreatic disorders</p> Signup and view all the answers

    What precaution is necessary when performing an upper GI fibroscopy?

    <p>Monitoring the patient’s oral airway during the procedure</p> Signup and view all the answers

    What type of patients should consult a cardiologist before a colonoscopy if they have specific devices?

    <p>Patients with implantable defibrillators and pacemakers</p> Signup and view all the answers

    For what reason might a patient need to be NPO prior to an endoscopic examination?

    <p>To prevent complications during anesthesia</p> Signup and view all the answers

    What is the role of glucagon during a colonoscopy procedure?

    <p>To relax colonic musculature</p> Signup and view all the answers

    What must be done before performing a colonoscopy to ensure patient safety?

    <p>Obtain informed consent</p> Signup and view all the answers

    What is the role of sclerosing solutions during therapeutic endoscopy?

    <p>To control upper GI bleeding</p> Signup and view all the answers

    What method is used to assess gastric motility through non-invasive means?

    <p>Gastric emptying studies</p> Signup and view all the answers

    What is a common position for patients during a flexible sigmoidoscopy?

    <p>On the left side with right leg bent</p> Signup and view all the answers

    What can be performed during a flexible sigmoidoscopy if necessary?

    <p>Biopsies and polypectomies</p> Signup and view all the answers

    Which of the following is NOT a type of endoscopic procedure for GI tract assessment?

    <p>Radionuclide imaging</p> Signup and view all the answers

    What is the purpose of monitoring vital signs during a colonoscopy procedure?

    <p>To check for potential complications</p> Signup and view all the answers

    What is the primary purpose of scintigraphy in medical diagnostics?

    <p>To visualize anatomy and identify abnormalities</p> Signup and view all the answers

    What technology is involved in capsule endoscopy for assessing the GI tract?

    <p>Wireless video transmission</p> Signup and view all the answers

    After a therapeutic colonoscopy, what should patients be specifically instructed to report?

    <p>Any bleeding</p> Signup and view all the answers

    What type of sedation is commonly administered to provide comfort during a colonoscopy?

    <p>Intravenous sedation</p> Signup and view all the answers

    What should patients be informed about regarding the side effects of midazolam?

    <p>They might have amnesic effects</p> Signup and view all the answers

    Study Notes

    Gastrointestinal (GI) Tract Assessment

    • GI tract abnormalities encompass various pathologies: bleeding, perforation, obstruction, inflammation, and cancer.
    • Factors impacting GI function include congenital, inflammatory, infectious, traumatic, and neoplastic lesions.
    • Extrinsic factors (stress, anxiety, fatigue, dietary changes) can also affect GI function.

    Anatomic and Physiologic Overview

    • The GI tract extends ~7-7.9 m (23-26 feet) from the mouth to the anus.
    • The esophagus, ~25 cm (10 inches) long, connects the pharynx to the stomach, passing through the diaphragmatic hiatus.
    • The stomach (capacity ~1500mL) stores food, secretes digestive fluids, and propels chyme into the small intestine. Regions: cardia, fundus, body, and pylorus (with pyloric sphincter).
    • The small intestine (~70m surface area) is the longest segment, consisting of the duodenum, jejunum, and ileum; ending at the ileocecal valve (regulates flow to large intestine). The appendix is attached to the cecum. The common bile duct empties into the duodenum.
    • The large intestine includes ascending, transverse, and descending segments, as well as the sigmoid colon, rectum, and anus. Anal sphincters (internal and external) regulate stool elimination (internal is involuntary, external is voluntary).
    • Blood supply to the GI tract is about 20% of cardiac output, increasing after meals. Major arteries include gastric, superior and inferior mesenteric arteries. The superior mesenteric vein drains small intestine and parts of large intestine corresponding to those arteries.
    • The autonomic nervous system (sympathetic and parasympathetic) innervates the GI tract. Sympathetic nerves inhibit, parasympathetic stimulate activity.

    Function of the Digestive System

    • Major functions include food breakdown, nutrient absorption (into bloodstream), and waste elimination.
    • Secretions help digest, absorb, or eliminate food throughout the GI tract.

    Chewing and Swallowing

    • Digestion begins with chewing (mechanical breakdown), triggering reflex salivation (1.5L/day from parotid, submaxillary, and sublingual glands).
    • Saliva contains enzymes (ptyalin/salivary amylase), water, and mucus to lubricate food for swallowing.
    • Swallowing is initially voluntary (controlled by medulla oblongata) then becomes a reflex propelling food through the esophagus.
    • Esophageal peristalsis forces food to stomach, and the lower esophageal sphincter prevents reflux.

    Gastric Function

    • The stomach stores and mixes food with highly acidic fluid (pH ~1, total ~2.4L/day), containing hydrochloric acid (HCl) to break down food and kill bacteria.
    • Pepsin (from pepsinogen) is a main protein-digesting enzyme.
    • Intrinsic factor, needed for B12 absorption (lack leads to pernicious anemia), is secreted by gastric mucosa.
    • Stomach contents (chyme) are mixed and propelled toward pylorus. This process breaks down large particles.
    • Food remains in stomach for 30 minutes to several hours based on factors. Hormones, neuroregulators and local substances control gastric secretions and motility.

    Small Intestine Function

    • Digestive process continues in the duodenum – secretions from pancreas, liver, and gallbladder help.
    • Pancreatic juice, has alkaline pH (bicarbonate) to neutralize acidic chyme. Digestive enzymes (trypsin, amylase, lipase) break down protein, starch and fat respectively.
    • Bile from liver (stored in gallbladder) emulsifies fats ("breaks them down into smaller pieces"). The sphincter of Oddi regulates bile flow.
    • Segmentation contractions mix intestinal contents, and peristalsis moves contents. Nutrients are broken down and absorbed in small intestine for 3 to 6 hours.
    • Villi (finger-like projections) increase surface area for absorption. Nutrients (Vitamins, minerals) are absorbed via active transport and diffusion. Specific locations for absorption: Jejunum and duodenum (fats, proteins, carbs, sodium, chloride), ileum (B12 and bile salts), and throughout the small intestine (Mg, phos, potassium).

    Colonic Function

    • Residual waste from meal enters large intestine (through ileocecal valve).
    • Gut microbes help break down undigested food and bile.
    • Secretions (electrolytes, bicarbonate solution and mucus) added to waste material.
    • Colonic peristalsis reabsorbs water and electrolytes.
    • Waste materials enter the rectum typically within 12 hours, though some can remain for 3 days.

    Waste Products of Digestion

    • Feces consist of undigested food, inorganic materials, water, and bacteria.
    • About 75% of feces is fluid, 25% solid.
    • Color and odor derive from bile breakdown and gut bacteria.

    Elimination of Stool

    • Rectal distention initiates reflex contractions and relax sphincters. Defecation is voluntary (external sphincter).
    • Abdominal muscle contractions aid in stool elimination. Regular defecation is usually one time a day, although this is variable.

    Gut Microbiome

    • Gut microbiota plays a role in vitamin synthesis, immune function (against pathogens), innate and adaptive immunity regulation, inflammation, and protection.
    • Established by ~2 years old
    • Affected by genetics, diet, hygiene, and infections, and aging

    Gerontologic Considerations

    • Aging has minimal effect on most GI functions, due to functional reserve.
    • Some GI disorders (e.g., dysphagia, dyspepsia) may increase in frequency.
    • Irritable bowel symptoms may decrease.

    Assessment of the Gastrointestinal System

    • Assessment includes health history and physical examination (oral cavity, abdomen, and rectum).

    Health History

    • Question patient about GI symptoms (pain, dyspepsia, gas, nausea/vomiting, diarrhea, constipation, fecal incontinence, jaundice, and previous GI disease).

    Common Symptoms

    • GI symptoms leading to healthcare referrals include pain, dyspepsia, gas, nausea/vomiting, diarrhea, and constipation.

    Pain

    • Character, duration, pattern, frequency, location, referred pain, and time of pain are key factors. Meals, rest, activity, and defecation impact pain.

    Dyspepsia

    • Upper abdominal discomfort after eating, often called heartburn or indigestion, affect ~25% of Americans.

    Intestinal Gas

    • Gas accumulation (belching and flatulence) can result from issues such as food intolerance or gallbladder disease leading to bloating and distention.

    Nausea and Vomiting

    • Nausea signals sickness, possibly indicating a pathologic process or caused by odors, activity, medications, or foods.
    • Vomiting is forceful emptying of stomach and intestinal contents. Emesis or vomitus may vary in color/content. Acute bright/coffee ground vomitus = potential upper GI bleeding (e.g., Mallory-Weiss tear). Many factors affect vomiting.

    Change in Bowel Habits and Stool Characteristics

    • Changes relate to colonic issues.
    • Diarrhea (increased frequency/liquidity) occurs when contents pass quickly.
    • Constipation (decreased frequency or hard/dry stools), linked with discomfort and bleeding.
    • Stool color (light to dark brown), consistency, and presence of blood can help diagnose.

    Past Health, Family, and Social History

    • Evaluate patient’s dental hygiene and routine and nutritional history
    • Determine risk factors like tobacco/alcohol use. Consider dietary changes. Assess for weight changes.

    Physical Assessment

    • Inspect the mouth (lips, gums, tongue, pharynx) for signs of inflammation/lesions. Examine abdomen for skin changes, contour, symmetry, and presence of peristaltic waves. (four or nine quadrants).
    • Auscultate for bowel sounds (normal, hyperactive, hypoactive/absent). Listen for vascular sounds and friction rubs.
    • Percuss to assess organ size & density, detecting air/fluid/solid masses.
    • Rectal examination checks the terminal GI tract (internal/external sphincters and internal organs).

    Diagnostic Evaluation

    • Multiple modalities assess GI tract (serum tests, stool tests, breath tests, imaging, endoscopic procedures).
    • Patient preparation varies depending on the test chosen (diet, medications, etc.).

    Serum Laboratory Studies

    • Initial tests include complete blood count, complete metabolic panel, clotting times, triglycerides, liver function tests, amylase, lipase, and potentially tumor markers (CEA). Serum tests help diagnose and monitor GI disorders including cancer.

    Stool Tests

    • Stool examination assesses consistency, color, and presence of occult blood. Collect random/quantitative samples following instructions/dietary restrictions as needed depending on specific test.
    • Fecal occult blood testing (gFOBT) is common for initial screening (avoid red meat, aspirin, NSAIDs, vitamin C for 72hrs pre-test) but is not used when hemorrhoidal bleeding is present. Sensitive alternative tests like FIT exist (avoiding factors like gFOBT.)

    Breath Tests

    • Hydrogen breath test evaluates carbohydrate absorption and bacterial overgrowth. Urea breath test detects H. pylori infection, specific instructions before the test regarding use of medications/antibiotics required.

    Abdominal Ultrasonography

    • Noninvasive technique using sound waves to image abdominal structures. Assess gallbladder, liver, pancreas, ovaries. Limited by patient body type, bowel gas, operator experience.

    Endoscopic Ultrasonography

    • Specialized endoscopic procedure for detailed GI imaging, useful for deeper examination.

    Upper Gastrointestinal Tract Study

    • Fluoroscopy views the upper GI tract after contrast agent administration. Identify and rule out abnormalities (ulcers, varices, tumors.) Double-contrast studies for detailed visualization of upper GI tissues. Enteroclysis is used for precise visualization for small bowel issues. Prepare patient with dietary modifications (low residue or clear liquids) and withholding medications and substances. Increased hydration is recommended after procedure.

    Lower Gastrointestinal Tract Study

    • Barium enema visualizes the large intestine. Other methods (double contrast, water-soluble contrast) also used to identify polyps, tumors, and abnormalities. Preparation is critical for visualizing the GI tract.

    Computed Tomography (CT)

    • Cross-sectional images of abdominal organs using multiple x-rays, digitized, and reconstructed. High-resolution imaging and shorter scan times, and less artifact created, and detection of inflammatory conditions (e.g., appendicitis.) Prepare patient regarding pre-test medications. Consider patient and clinician need for contrast, weigh risk factors. (allergies, kidney function and pregnancy status).

    Magnetic Resonance Imaging (MRI)

    • Uses magnetic fields and radio waves. May use oral contrast to enhance image quality. Useful in GI assessment of soft tissues and blood vessels. Important considerations related to ferromagnetic objects need to be made.

    Positron Emission Tomography (PET)

    • Detects radiation emitted from radioactive substances after injection to identify areas of heightened metabolism. Used to diagnose malignant/benign tumors and staging.

    Scintigraphy (Radionuclide Testing)

    • Uses radioactive isotopes. Evaluate organ function, size/shapes, neoplasms. Assess bleeding locations, inflammation. Assess for patient allergies, especially those related to the contrast.

    Gastrointestinal Motility Studies

    • Radionuclide studies assess gastric emptying and colonic transit time measuring rate substances pass through the parts of the GI tract. Studies used for evaluation of GI motility/obstructions

    Endoscopic Procedures

    • Various scopes (fibroscopy/EGD, colonoscopy, anoscopy, proctoscopy, sigmoidoscopy) provide direct visualization of GI tract sections. Capsule endoscopy (pillcam ESO) is useful for upper GI tract issues.
    • Endoscopic retrograde cholangiopancreatography (ERCP) assists in visualization of bile ducts and pancreatic ducts. This procedure can be therapeutic (removing stones, dilating strictures. Important considerations related to patient safety should be addressed.

    Nursing Interventions

    • Nursing care emphasizes patient education, pre- and post-procedure care, comfort, and addressing patient's risks (especially older adults and patients with comorbities) and patient safety and risks concerning medications, allergies, and complications. Monitor pertinent parameters like vital signs, fluid/electrolyte balance, and oxygen saturation levels.

    Genetic Testing

    • Recent research has improved risk assessment, preclinical diagnosis, and prenatal diagnosis of genetic GI disorders. Genetic counseling options, and preventing and treating the disease exist, and are available for those detected to be at risk

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    Test your knowledge on the normal functions and common pathologies of the gastrointestinal tract. This quiz covers key concepts such as the structure, length, and roles of various components within the GI system. Ideal for students studying anatomy or medicine.

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