Gastrointestinal Tract Anatomy

Disturbances in Metabolism:

• This covers anatomy of the gastrointestinal tract, disturbances, functions, assessment, and diagnostic measures of the digestive system, plus common nursing diagnoses

Anatomy of the Gastrointestinal Tract:

• The GI tract is a 23-26 feet long pathway extending from the mouth to the anus

Digestive System Groups:

• The gastrointestinal tract (GI tract) includes organs where food passes through the body
• Accessory digestive organs break down food through chewing actions or via chemicals such as saliva

Mouth:

• The mouth contains the upper and lower lip, gums, teeth, palate, anterior and posterior pillars, tonsils, tongue, pharynx, and uvula

Pharynx role:

• Acts as a passageway for food from the mouth to the esophagus
• Serves as an air passage from the nasal cavity and mouth to the larynx

Esophagus location and function:

• Located in the mediastinum within the thoracic cavity, anterior to the spine and posterior to the trachea and heart
• The esophagus is a collapsible tube, 25 cm (10 in) in length

Esophagus anatomy:

• Passes through the diaphragm at an opening called the diaphragmatic hiatus

Stomach location and anatomical features:

• The stomach is situated in the upper portion of the abdomen, to the left of the midline, just under the left diaphragm
• It can accommodate 1,500 ml

Sphincters and Stomach Regions:

• The esophageal sphincter (cardiac sphincter) closes off the stomach from the esophagus
• The pyloric sphincter controls the opening between the stomach and the small intestines
• The four anatomical regions of the stomach:
  • Cardia (entrance)
  • Fundus (expanded part)
  • Body (the midportion)
  • Pylorus (outlet has the pyloric antrum)

Small Intestine:

• It is the longest segment, making up about 2/3 of the GI tract
• Provides about 7000 cm² surface area for secretion of digestive enzymes and absorption
• Absorption is the process by which nutrients enter the bloodstream through the intestinal walls

Small Intestine Anatomical Parts:

• Duodenum: First segment, receives secretions via the common bile duct for bile and pancreatic enzymes
• Jejunum: The second portion, is larger, thicker-walled, and more vascular
• Ileum: The terminal portion contains the ileocecal valve

Cecum:

• Junction between the small and large intestines, located in the right lower abdomen
• The Ileocecal Valve controls the passage of intestinal contents into the large intestines, preventing bacteria reflux into the small intestines
• The Verniform Appendix is situated in the cecum

Large Intestines Segments:

• Ascending colon: Right side of the abdomen
• Transverse colon: Extends from the right to the left in the upper abdomen
• Descending colon: Left side of the abdomen

Sigmoid Colon & Rectum:

• Terminal portion of the large intestines
• Anus has a network of striated muscles regulates the anal opening via internal and external anal sphincters
• Mesenteric veins and arteries supply and remove body nutrients
• Blood flow to the GIT is about 20% of total cardiac output, increasing significantly after eating

Functions of the Digestive System:

• Primary functions:
  • Break down food particles into molecular form
  • Absorption into the bloodstream as small molecules
  • Eliminate undigested/unabsorbed material
• Digestion begins with chewing, breaking food into small pieces which are mixed with the digestive enzymes

Gastric Function:

• Stores and mixes food with secretions
• Secretes HCI (2.4 L/day) in response to anticipated food intake
• Functions of HCI include:
  • Aids by breaking down food into more absorbable components
  • Destroys ingested bacteria
• Pepsin (from pepsinogen), a component of HCI, initiates protein digestion
• Intrinsic factor, secreted by gastric mucosa, combines with B12 for absorption in the ileum; its absence causes pernicious anemia

Small Intestine Function:

• Secretions in the duodenum come from the accessory digestive enzymes such as the pancreas, liver, gall bladder, and glands in the intestine itself
• Pancreatic secretions and digestive enzymes are alkaline due to high concentrations of carbonate, which neutralizes acids entering the stomach

Digestive Enzymes:

• Trypsin aids in protein digestion
• Amylase supports starch digestion
• Bile, from the liver and stored in the gall bladder, helps emulsify fats for digestion and absorption
• Intestinal glands secrete mucus (which then produces gastrin), enzymes, electrolytes, and hormones

Colonic Function:

• Within 4 hours of eating, residual waste materials pass into the colon through the ileocecal valve
• Bacteria are the major component of the colonic contents
• Peristaltic activity moves the colonic contents slowly
• The transport allows the primary purpose of the colon that is water and electrolyte reabsorption from digested foods
• Waste material reaches and distends the rectum usually around 12 hours

Waste Product:

• Consists of undigested food, inorganic materials, water (75%), and solid material (25%)
• Bowel movement frequency varies among individuals but should happen on a daily basis

Accessory Organs:

• Salivary glands produce saliva, which is a mixture of mucus and serous fluid
• Teeth (Incisor (cutting), canines (tearing/piercing), premolars and molars (grinding)
• Liver is the largest organ, responsible for producing bile
• Gall bladder stores bile
• Pancreas secretes amylase, trypsin, lipase and nuclease

Digestion Assessment:

• Complete health history, focusing on GI symptoms
• Assess previous GI diseases
• Evaluate alcohol and tobacco use, dietary habits, weight changes, and stool characteristics

Diagnostic Assessment:

• Provides general info on healthy diets, dietary considerations and nutritional factors that alleviate Gl disturbances
• Nausea, vomiting, and changes in bowel patterns
• Inspect mouth, tongue, mucosa, teeth, and gums, palpitation at four quad abdomen
• Note ulcers, nodules, swelling and discoloration and inflammation
• Provides specific nutritional guidance based on diagnosis
• Provides information about any diagnostic testing and or activity restrictions
• Alleviate anxiety and provides emotional support during examination

Stool Analyses:

• Examines consistency and color tests for occult blood
• Tests fecal urobilinogen, fat, nitrogen, parasites, pathogens, food residues and more
• 24-72 quantitative collections refrigerated until tested, dietary and medical restrictions

Breath Tests:

• Hydrogen tests evaluate carbohydrate absorption and diagnosis bacterial overgrowth in intestines and short bowel
• Urea tests presence of Helicobacter pylori, to determine the potential for peptic ulcer and or stomach degradation, antibiotics and loperamide should be discontinued one month prior

Abdominal Ultrasonography:

• Noninvasive method using soundwaves that detects cholelithiasis, cholecystitis, appendicitis, acute colonic diverticulitis

Endoscopic Ultrasonography:

• Specialized enteroscopic procedure diagnosing Gl disorders through direct imagining
• Requires fasting 8-12 hours before the test, low fat meal the evening before, barium scheduled after due to sound interference

DNA testing:

• Allows minimizing diseases by intervening before onsets and improving therapy, especially for people at risk with colonic concerns

The following imaging studies are included:

• X-Ray contrast studies
• Magnetic resonance images
• Radio nucleic imaging
• Computer Tomography scan

Upper GI Tract Radiography (Barium Swallow):

• Consists of a fluoroscopy used to detect ulcers, GERD, esophagitis, benign tumours etc
• Nursing interventions include low residue diet prior to test , patient to stay NPO, no jewelry for testing

Lower GIT Study:

• Barium enema used to detect presence of polyps, tumors, fistulas, obstructions, and abnormalities.
• Nursing implies low residue diet, clear liquid diet the evening before, NPO after midnight, enemas until clear to prep

CT Scans:

• Provide sectional images for the liver, spleen, and pelvis, can identify appendicitis, diversion etc.
• Nursing requires not eating 6-8 hours before, allergies to dye should be disclosed

MRI:

• Non invasive procedure producing images through radio-waves and magnetic fields, which evaluates abdominal tissues and blood vessels.
• Patients with defibrillators, metallic objects and jewelery should not have this

Radionuclide:

• Relies on radioactive isotopes to help reveal displaced anatomic locations, measures extent of inflammation and food substances

GI Motility:

• Can be used to measures GI motility or esophageal
• Ex. Esophageal Manometry measures strength of muscles and diagnoses swallowing disorders

Upper Gl Fibroscopy:

• Helps visualize gastric or duodenal mucosa through an esophagogastroduodenoscopy, requiring an NPO for 6-12.
• Involves administering a moderate dose of midazolam to alleviate anxiety and anxiety to reduce secretions

Anoscopy:

• Examines anus and rectum to assess diarrhea, change in bowel patterns, etc.
• Requires tap water enemas until clear

Fiberoptic coloscopy:

• Visually inspects anus, requires intake fluid intake for 24-72 hours and laxatives and NPO before procedure

Small bowel enteroscopy

• Involves small caliber transanal endoscope inspecting insides of the small intestines

Endoscopy:

• Can be performed through an ostomy viewing small or large intestine

Gastric Analysis:

• Measures intraluminal presures or gastro motility or gastric activity through electrodes

Defecography:

• Measures anorectal functions

Nursing Diagnoses:

• Alteration in health, disturbed concept, impaired swallowing
• Planning entails considering alternative feedings and maintenance nutrition

Common Health problems

• Failure to thrive is a term to describe infants whose weight and health falls below the percentile range
• Problems are classified stemming from physical cause, psycho-social, or idiopathic factors
  • Children under 5th percentile are considered growth stunt, exhibit developmental delays, withdrawn behaviour and poor hygiene

Nursing:

• Requires consistent caregivers, monitor accurate record of intake and weight to determine the feeding environment

Thereapeutic Interventions:

• Proper emotional and nutritious environment promotes a positive response
• Monitor growth, feed behavior and developmental level

Cleft Lip:

• Results from failure of unison embryonic structure
• Occurs 5-8 weeks into fetal life
• Can induce secondary maternal infant

Therapy:

• Involves surgery to repair defect performed shortly after childbirth to improves sucks and appearance and improve suck
• Assessment entails feeding habits and signs of infection:

Nursing for Child Birth:

• Reduce restrictive oral pain intake
• Administer soft large nipples
• Maintain airways and clean the sutre line

Child Birth:

• If a mother is pregnant with a cleft lip is at 4% chance of having the same, 1000 born with defect in 20 birth

Cleft Palate:

• Lack of hereditary infuence, or palatal structures between weeks 9 and 12 and 1 per 1000 birth
• Can be inspected visually under anesthesia, and repaired to prevent air trapping
• Child usually requires assistance from a speech therapist, and increased hygiene as needed

Gastriel Ulcer:

• Ulcers are classified as excavation in the stomach or duodenum, and erotion through the membranes of the perritoneum
• Erosion due to high concentraitions acids and activity high Risk for erosion in duodenum Risk for 40 to 60 y/o Causes: poor dietary, H pillory, chronic pain, smoking

Clinincal Findings:

• Findings are associated with vomiting dehydration with epigastrium and mass palpication on ubdicus

Management

• Require anti biotrics and pain medications
• Focuses on improving gastric issues and preventing secretion

Dumping Syndrome:

• Results from empty in stomach lasting 25 to 30 minutes
• Presents in symptoms such low blood pressure, palpitations and dizziness
• Treatment involves meds for side efeects and frequent meals

Esophogeal

-Results from birth effect, can result in fluid retention and mucus build up, three C to assess ( coughing, cyonasis)