chapter 45: disorders of gastrointestinal function Flashcards
signs and symptoms common to gastrointenstinal disorders
- anorexia
- nausea
- vomiting
- gastrointestinal bleeding
Anorexia, nausea, retching, and vomitting
- anorexia, nausea, and vomiting are physiologic responses that are common to many GI disorders
- Retching consts of the rhythmic spasmodic movements of the diaphragm, chest wall, and abdominal muscles
- signal for disease and removes noxious agents
- contributes to impaired intake or loss of fluids and nutrients
vomiting and neural structures
- vomiting involves two functionally distinct medullary centers- the vomiting center and the chemoreceptor trigger zone
- vomiting center: located in the medulla near the sensor nuclei of the vagus nerve
- Chemoreceptor trigger zone: located in small area on the floor od the brains fourth ventricle, where it is exposed to both blood and cerebospinal fluid. reacts to the emetic effects of blood-borne drugs and toxins
swallowing
- mechanisms:
- depends on the coordinated action of the tongue and pharynx
- theses structures are innervated by cranial nerves V,IX, X
- alterations:
- dysphagia: difficulty swallowing
- Odynophagia: painful swallowing
- achalasia: failure of the esophageal sphincter to relax
Gastroesophageal Reflux a.k.a GERD
- heart burn: 30-60 minutes adter meal, typically an evening onset, pain in the epigastric area (can radiate),
- how to overcome GERD?
- avoid large meals, smoking, alcohol, bending for long periods or with pillows, recumbent position several hours after a meal
- eat meals sitting up, sleep with head of bed elevated, losing weigh if overweight
Complaints accompanying esophageal
the food stops before it reaches the stomach,
gurgling, belching, coughing, foul-smelling breath
esophageal cancer
-squamous cell carcinoma
+alcohol and tobacco use
-Adenocarcinoma
+which has a close association with Barret’s esophagus (reflux leads to metaplasia of epithelial cells which can lead to cancer in lower esophagus)
-Symptoms
+dysphagia, weight loss, anorexia,fatigue,painful swallowing, not easily diagnosed
factors contributing to the protection of gastric mucosa
- gastric mucosal barrier exists in the stomach
+ there should be an impermeable epithelial cell surface covering protecting the stomach
+there are mechanisms for the selective transport of hydrogen (hydrocholric cid) and bicarbonates ions
+ there are 2 characteristic types of gastric mucus
Types of mucus protecting the gastric mucosa
-water-insoluble mucus: +forms, a thin stable gel that adheres to the gastric mucosal surface. +Provides protection.
+forms an unstirred layer that traps bicarbonate, forming an alkaline interface between the luminal contents of the stomach and its mucosal surface
-water-soluble mucus
+washed from the mucosal surface
+mixes with the luminal contents
+ its viscid nature makes it a lubricant that prevents mechanical damage to the mucosal surface
major cause of gastric irritation and ulcer formation
- Asipirin or nonsteroidal anti-inflammatory drugs (NSAIDS): irritates the gastric mucosa and inhibit prostaglandin synthesis
- infection with H.pylori: thrives in an acid environment of the stomach & disrupts the mucosal barrier that prtects the stomach from harmful effects of its digestive enzymes
Types of gastritis
- acute gastritis
- chronic gastritis
acute gastritis
- a transient inflammatino of the gastric mucosa
- most commonly associated with local irritants such as bacterial endotoxins, alcohol, and aspirin
chronic gastritis
- characterized by the absence of grossly visible erosions and the presence of chronic inflammatory changes
- leads eventually to atrophy of the glandular epithelium of the stomach
major types of chronic gastritis
- helicobacter pylori gastritis
- autoimmune gastritis
- multifocal atropic gastritis
- chemical gastropathy
Helicobacter pylori
- colonize the mucus-secreting epithelial cells of the stomach
- produce enzymes and toxins that have the capacity to interfere with the local protection of the gastric mucosa
- produce intense inflammation
- elicit an immune response
methods establishing presence of H. Pylori infection
- C urea breath test using a radioactive carbon isotope
- stool antigen test
- endoscopic biopsy for urease testing
- blood tests to obtain serologic titers of H. Pylori antibodies
peptic ulcers
ulcerative disorders that occur in areas of the upper GI tract that are exposed to acid-pepsin secretions
-spontaneous remissions and exacerbations are common
-causes
+H. pylori, aspirin, age, warfarin, smoking
complications of peptic ulcer
H.O.P
-Hemorrhage
+cause by bleeding from granulation tissue or from erosion of an ulcer into an artery or vein
-Obstruction:
+ caused by edema,spasm, or contraction of scar tissue and interference with the free passage of gastric contents through the pylorous or adjacent areas
-Perforation
+occurs when an ulcer erodes through all the layers of the stomach or duodenum wall. bleeding and spilling of gastric contents into the perotoneum could be fatal
GI tract bleedin
-HEMATEMESIS
+ blood in the vomitus
+ may be bright red or have coffee groun appearance
-MELENA
+blood in the stool
+ranges in color from bright red to tarry black
+may be occult (hidden). we can hemoccult test
Treatment of Peptic Ulcer
-Eradicate the cause and promote a permanent cure for the disease, usual meds:
-Eradicating H. pylori with 2 antibiotics
+Mucosal protective like Carafate
+Antacids to relieving ulcer symptoms like Maalox, Tums
+Use of a Proton pump inhibitors like Prevacid, Protonix
+Maybe a prostaglandin agonist like Cytotec or H2 antagonist like Zantac instead of a PPI
+Discouraging alcohol, NSAIDs, ASA
Risk factors for development of stress ulcers
-large-surface area burns, trauma, sepsis, acute resp. distress syndrom, severe liver failure, major surgical procedures, zollinger-ellison syndrome
risk factors for dev. gastric cancer
-genetic predisposition, carcinogenic factors in the diet, autoimmune gastritis, gastric adenomas or polyps
conditions causing altered intestinal function
-irritablebowel disease, inflammatory bowel disease, diverticulitis, appendicitis, alteration in bowl motility, malabsorption syndrome, cancer of the colon and rectum
infections of the intestine
-VIRAL INFECTION \+rotavirus -BACTERIAL INFECTION \+clostridium difficile colitis \+escheichia coli O157:H& Infection - PROTOZOAL INFECTION \+E. Histolytica
characteristic of irritable bowel disease
-persistent or reccurent symptoms of abdominal pain, altered bowl function, varying complaints of flatulence, bloatedness, nausea and anorexia, constipation or diarrhea, anxiety or depression
Inflammatory bowel disease
-CROHN DISEASE
+Recurrent, granulomatous tpe of inflammatory response that can affect any area of the GI tract from the mouth to the anus
-ULCERATIVE COLITIS
+ A nonspecific inflammatory condition of the colon
symptoms of diverticulitis
-pain in the lower left quadrant, nausea and vomiting, tenderness in the lower left quadrant, a slight fever, an elevated while blood cell count
Appendicitis
- the appendix becomes inflames, swollen, and gangrenous, and it eventually perforates if not treated
- appendicitis is related to intraluminal obstruction with a fecalith ( hard poop), gallstones, tumores, parasites, or lymphatic tissue
Types of diarrhea
-Large volume
+osmotic, secretory
-Small-volume
+inflammatory bowel disease, infectious disease, irritable colon
manifestation of classic form of celiac disease
-presents in infancy
-manifests as
+faulire to thrive, diarrhea, abdominal distention, occasionally, severe malnutrition
common cause of constipation
- failure to respond to the urge to defecate
- inadequate fiber in the diet
- inadequate fluids
- weakness of the obdominal muscles
- inactivity and bed rest
- preggers
- hemorrhoids
fecal impaction
- painful anorectal disease
- tumors
- neurogenic disease
- use of constipating antacids or bulk laxatives
- a low-residue diet
- drug-induces colonic stasis, paralytic ileus
- prolonged bed rest and debility
INTESTINAL OBSTRUCTION
- mechanical obstruction can result from post operatice causes such as external hernia and postoperatice adhesions
- paralytic, or adynamic, obstructino results from neurogenic or muscular impairment of peristalsis
- mechanical (twist stool)
- paralytic
- abdominal distention, n/v, high pitch bowel sounds, no flatus, loss of fluids and electrolytes, may necessitate NG tube placement and/or surgery
perotoneal caivty and perotonitis
-permits rapid absorption of bacterial toxins
-favors the dissemination of contaminants
-great inflammatory response (thick, fifrinous protective substance)
-causes?
+perforated peptic ulcer, ruptures appendixm perforated diverticulum, gangrenous bowel, PID, nangrenous gallbladder, abdominal trauma and wounds
intestinal malabsorption
- failure to transport to dietary constituents from the lumen of the intestine to the extracellular fluid
- Causes: Celiac disease
- symptoms: diarrhea, steatorrhea, flatulence, bloating, abdominal pain, cramos, weakness
colorectal cancers and testing
- age, family history, crohn disease, ulcerative colitis, diet
- stool occult blood test, digital rectal examination, x-ray studies using barium, flexible sigmoidscopy and coloscopy
