6 gi system
TRANSCRIPT
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Gastrointestinal systemPart I
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Function of G I system
The Primary Digestive Functions are
1. Break down food particles to absorbable
forms2. Absorb the small molecules into the
bloodstream
3. Eliminate waste products & undigestedfood
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Impaired Esophageal Motility
(Achalasia) Achalasia: characterized by impaired peristalsis
of smooth muscle of esophagus and impaired
relaxation of lower esophageal sphincter
Manifestations:
1. Dysphagia
2. chest pain (pyrosis)
3. Sensation of food stick in lower esophagus
4. Food regurgitation
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Gastroesophageal
Reflux Disease(GERD)
Gastroesophageal reflux
is the backward flow of gastric content into the
esophagus
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Gastroesophageal Reflux Disease (GERD)
2.Pathophysiology a. Gastroesophageal reflux results from transient
relaxation or incompetence of lower esophagealsphincter, or increased pressure within stomach
b. Factors contributing to Gastroesophageal reflux1.Increased gastric volume (post meals)
2.Position pushing gastric contents close toGastroesophageal juncture (such as bending or lying
down)3.Increased gastric pressure (obesity or tight
clothing)
4.Hiatal hernia
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Gastroesophageal Reflux Disease
(GERD)
Manifestations1. Heartburn after meals, while bending over, or
recumbent
2. Dyspepsia or indigestion3. Regurgitation of sour materials
4. Atypical chest pain
5. Sore throat with hoarseness
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Hiatal Hernia
Part of stomach protrudes through theesophageal hiatus of the diaphragm intothoracic cavity
Types
1. Sliding hiatal herni
2. Paraesophageal hiatal hernia:
( hernia can become strangulated; maydevelop gastritis with bleeding)
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Gastritis1.Definition: Inflammation of stomach lining from
irritation of gastric mucosa.
2.Types:
A. Acute Gastritis: Disruption of mucosal barrier
allowing hydrochloric acid and pepsin to havecontact with gastric tissue: leads to irritation,inflammation, superficial erosions.
Gastric mucosa rapidly regenerates (self-limitingdisorder)
B.Chronic Gastritis: Progressive disorder beginning with superficial inflammation and leadsto atrophy of gastric tissues (prolong Gastritis)
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Gastritis
Causes of acute gastritis a. Irritants include aspirin and other NSAIDS,
corticosteroids, alcohol, caffeine b.Ingestion of corrosive substances: acid
c.food contamination (microorganisms)
Manifestations Epigastric discomfort
abdominal pain, nausea, vomiting
Heart burn , &sour taste in mouth If perforation occurs, signs of peritonitis
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gastritis
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Peptic Ulcer Disease (PUD)
Definition: Break in mucous lining of GI tract comes into
contact with gastric juice , referred to as gastric,duodenal , or esophageal ulcer
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Peptic Ulcer Disease (PUD)
2.Pathophysiology
a. Acute Ulcers or breaks in mucosa of GI tractoccur with
1.H. pylori infection (spread by oral to oral,fecal-oral routes) damages gastric epithelialcells reducing effectiveness of gastric mucus
2.Use of NSAIDS: interrupts prostaglandinsynthesis which maintains mucous barrier of gastric mucosa
b. Chronic with spontaneous remissions andexacerbations associated with trauma, infection,physical or psychological stress
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Peptic Ulcer Disease (PUD)
Manifestations Pain is classic symptom: burning, occurs when
stomach is empty (pain: food: relief pattern)
Vomiting , nausea , constipation &diarrhea
presenting symptom may be complication: GIhemorrhage or perforation of stomach or duodenum
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Peptic Ulcer Disease (PUD)
Treatment Pharmacologic therapy
1. H2 receptor antagonist
2. Proton pump inhibitors3. Antacid
Stress Reduction & Rest
Smoking Cessation
Dietary Modification
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Acute Inflammatory Intestinal Disorders
(Appendicitis)
Pathophysiology:
Obstruction of the appendix lumen by faecolith,
enlarged lymph node, worms, tumour, brings about a
raised intra-luminal pressure, which causes the wall of the appendix to become distended. invasion by
bacteria found in the gut normally.
Clinical Manifestations
Rt Lower Quadrant pain, Fever, nausea , vomitinganorexia, tenderness, rebound tenderness.
Complications:
perforation peritonitis or abdominal abscess
,occurs after 24 hrs after onset of symptoms
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Irritable Bowel Syndrome (IBS)
Definition
a. Functional GI tract disorder without
identifiable cause characterized byabdominal pain and constipation, diarrhea,
or both
b. Affects up to 20% of persons in Western
civilization; more common in females
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Irritable Bowel Syndrome (IBS)
Pathophysiology a. Appears there is altered CNS regulation of
motor and sensory functions of bowel
1.Increased bowel activity in response to food
intake, hormones, stress
2.Increased sensations of chyme movementthrough gut
3.Hypersecretion of colonic mucus
b. Lower visceral pain threshold causingabdominal pain and bloating with normal levels of gas
c. Some linkage of depression and anxiety
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Irritable Bowel Syndrome (IBS)
Manifestations
a. Abdominal pain relieved by defecation
b. Altered bowel habits, abdominal bloating,
excess gas c. Nausea, vomiting, anorexia, fatigue,
headache, anxiety
d. Tenderness over sigmoid colon uponpalpation
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Peritonitis
Inflammation of peritoneum, lining that coversabdominal wall (parietal peritoneum) and organsof abdominal cavity (visceral peritoneum)
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Peritonitis
Pathophysiology: a. Peritonitis results from contamination of normal
sterile peritoneal cavity with infections or chemicalirritant.
b. Release of bile or gastric juices initially causeschemical peritonitis; infection occurs when bacteriaenter the space.
c. Bacterial peritonitis usually caused by thesebacteria (normal bowel flora): Escherichia coli,
Klebsiella, Proteus, Pseudomonas. d. Inflammatory process causes fluid shift into
peritoneal space (third spacing); leading tohypovolemia, then septicemia.
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Peritonitis
3. Manifestations
Presents with ³acute abdomen´
1.Abrupt onset of diffuse, severe abdominal pain
2.Pain may localize near site of infection3.Intensifies with movement
Entire abdomen is tender with board like rigidity
paralytic ileus
Systemically: fever, malaise, tachycardia«.
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Inflammatory Bowel DiseaseInflammatory Bowel Disease
Includes:
Ulcerative colitis
Crohn¶s disease.
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Ulcerative Colitis
Pathophysiology 1. Inflammatory process usually confined to
rectum and sigmoid colon
2. Inflammation leads to mucosal hemorrhages
and abscess formation, which leads to necrosisand sloughing of bowel mucosa
3. Mucosa becomes red, friable, and ulcerated;bleeding is common
4. Chronic inflammation leads to atrophy,narrowing, and shortening of colon
Manifestations
Bloody Diarrhea with mucus
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Ulcerative Colitis
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Crohn¶s Disease (regional enteritis)
Pathophysiology 1. Affect any portion of GI tract, but terminal ileum
and ascending colon are more commonly involved
2. Inflammatory ulceration of mucosa andsubmuscosa develops into ulcers and fissures that
involve entire bowel wall 3. Fibrotic changes occur leading to local
obstruction, abscess formation and fistula formation
4. Fistulas develop between loops of bowel, bowel
& bladder and bowel & skin. 5. Absorption problem (protein loss and anemia)
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Crohn¶s Disease
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Intestinal Obstruction
Definition
a. May be partial or complete obstruction
b. Failure of intestinal contents to move through
the bowel lumen; most common site is smallintestine
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Intestinal Obstruction
Pathophysiology
a.Mechanical
1.Problems outside intestines: adhesions (bands of scar tissue), hernias
2.Problems within intestinal wall: tumors
3.Obstruction of intestinal lumen (partial or complete)
a. Intussusception: telescoping bowel
b. Volvulus: twisted bowel c. Foreign bodies
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IntussusceptionVolvulus
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Adhesions
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Intestinal Obstruction
Functional1.Failure of peristalsis to move intestinal contents:
(paralytic ileus, ileus) due to neurologic or muscular impairment
2.Causes include a. Post gastrointestinal surgery
b. Tissue anoxia or peritoneal irritation fromhemorrhage, peritonitis, or perforation
c. Hypokalemia
d. Medications: narcotics, anticholinergic drugs,antidiarrheal medications
e. Renal colic, spinal cord injuries, uremia
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Intestinal Obstruction
Manifestations Small Bowel Obstructionb.Colicky abdominal pain
c.Vomiting
1. Proximal intestinal distention stimulates
vomiting center 2. Distal obstruction vomiting may become
feculent
d.Bowel sounds
1. Mechanical obstruction: borborygmi may havevisible peristaltic waves
2. Paralytic ileus, diminished or absent bowelsounds
e.Signs of dehydration