alterations in the GI SYSTEM: structures, function, complications, disorders(stomach and GI)

Structures of the Upper GI system

• Mouth

• Esophagus

• Stomach

Major physiologic function of the GI system:

Digest food & absorb nutrients into the bloodstream.

Function of the Upper GI system

Intake source; initial digestive processes

Middle GI system structures:

• Duodenum

• Jejunum

• Ileum

What is the function of the Middle GI system

Most digestive and absorptive processes

What is the structures of Lower GI system

• cecum

• colon

• rectum

What is the functions of the Lower GI system

Storage channel for efficient elimination of waste

What are the acessory organs

• Salivary glands

• Liver

• Gallbladder

• Pancreas

What is the function of the acessory organs

Produce secretions that aid in digestion

What is the Movement of food and fluids along in the GI tract that promotes digestion and absorption.

Gastrointestinal motility

What is the molitilty of the GI tract controlled by

hormones and the ANS

What is being described

• Many different species of bacteria reside in the intestines

• These bacteria function to aid in digestion and metabolism, absorb vitamins/minerals, produce certain nutrients, and protect against “bad” bacteria

• Normal bacteria that reside in our GI tract

Intestinal Flora

What COMMON MANIFESTATION OF MANY GI DISORDERS is being described..

1.     Loss of appetite

2.     Factors influencing appetite:

• a.     Hunger

• b.     Smell

• c.     Emotional factors

• d.     Drug and disease states

• 3.     Often a forerunner of nausea

anorexia

What COMMON MANIFESTATION OF MANY GI DISORDERS is being described..

1.  Conscious sensation resulting from stimulation of the medullary vomiting center in the brain. May precede or accompany vomiting.

2.  May function as an early warning sign of a pathologic process

3 subjective

nausea

What are causes of nausea?

•    Motion sickness

•   Dizziness

•    Migraine

•      Fainting

•     Low blood glucose

• Gastroenteritis

•     Pain

•     Hypoxia

• Pregnancy (hormones)

• Side effect of medication

What are the manefestations of nausea (ANS manefestations, specifically SNS)

• watery salivation

• pallor(due to vasoconstriction)

• sweating

• tachycardia

What COMMON MANIFESTATION OF MANY GI DISORDERS is being described..

• Sudden, forceful expulsion of stomach contents (called vomitus). Protective mechanism from potentially noxious or damaging agents in the stomach and small intestine.

• Causes of this are similar to those producing nausea

vomiting

What are manefestations of vomiting (PNS manefestations)

• dizziness,

• light headedness,

• decreased blood pressure

• bradycardia

   

What COMMON MANIFESTATION OF MANY GI DISORDERS is being described..

• defintion: Excessively frequent passage of loose or unformed stools

• can be acute or chronic

diarrhea

What is acute diarrhea?

•  Commonly caused by infectious agents

• Non-inflammatory (large volume) diarrhea

  • Large volume watery, non-bloody stools

  • Cramps, bloating, nausea, vomiting also usually present

• Inflammatory (small volume) diarrhea

  • Presence of fever and bloody diarrhea

                     

What is chronic diarrhea

• > 4 weeks

• Associated w/ other conditions

What are causes of diarrhea

• Intestinal disorders (disorders affecting GI motility or causing inflammation)

•   Medications

• Microorganisms

• Foods

What COMMON MANIFESTATION OF MANY GI DISORDERS is being described..

•  Infrequent, incomplete, or difficult passage of stools.

• “Normal” bowel habits are subjective

  • Depends from person to person, we all have our own schedule for bowel movements

consitpation

What are causes of Constipation

o aging

o   Medications

o   Obstructing lesions of GI tract

o   Other GI disorders

o   Decrease in fluids

o   Decreased fiber in diet

•   Fiber bulks up the stool, makes it softer and fuller making it easier to pass, if you don’t have any stool is harder and smaller

o   Failure to defecate when the urge occurs (holding it in!)

o   Neurologic disorders

o   Sedentary lifestyle

o   Hypothyroidism

What COMMON MANIFESTATION OF MANY GI DISORDERS is being described..

•   May be diffuse or localized

• Caused by inflammation, ischemia, or mechanical problem

•    We want to know the location, it helps understand the problem

Abdominal Pain

What common gi complaction is being described

1.  GI organs are hollow- risk of formation of a hole with some GI conditions

2.  Very serious condition: Perforation—> contents that should normally remain in the GI tract can leak into the peritoneal cavity —> can lead to inflammation called Peritonitis

3.  Think of it as we have poked a hole in one of the hollow organs and now its leaking out into the peritoneal cavity

perforation

Perforation—> contents that should normally remain in the GI tract can leak into the peritoneal cavity —> can lead to inflammation called

Peritonitis

What common gi complaction is being described

• GI tract is very vascular, large amounts of blood can be lost with bleeding

• May be venous or arterial

• Risk of hypovolemic shock!

• Upper vs. Lower GI Bleed:

  • Both may lead to decreased H/H, hypotension, and fluid volume deficit!

• Hypovolemia —> Hypovolemic Shock

• Electrolyte Imbalances

Gastrointestinal Bleeding

What kind of GI bleed is being desrcibed

Esophagus, stomach, duodenum

Hematemeis(vomiting blood)- Bright red(fresh blood) vs. coffee ground(older blood)  Can be Life threatening

upper GI bleed- more common

What is Hematemesis (Upper GI bleed)

(vomiting blood)-

Bright red(fresh blood) vs. coffee ground(older blood)

What kind of GI bleed is this

Small/large intestines, rectum

Melena (dark purple-ish blood) Hematochezia(bright red blood, newer blood probably from descending colon or rectum) Maroon stool Can be life threatening

Lower GI Bleed

What is melena (lower GI bleed)

(dark purple-ish blood)

What is hemtochezia? (lower GI bleed)

(bright red blood, newer blood probably from descending colon or rectum)

What is the Tube connecting the oropharynx and the stomach.

esophagus

What is the function of the esophagus

Conduit for the passage of food and liquid from the pharynx to the stomach

Disorder of GI function: Disorders of the Esophagus

• Dysphagia

• Gastroesophageal Reflux

  •   Gastroesophageal Reflux Disease (GERD)

• Cancer of the Esophagus

What disorder of the esophagus is being described?

1.     difficulty swallowing

2.   May result from neuromuscular or structural causes

  Neuromuscular: Lesions of the CNS ex: having a stroke

 Structural: Cancer of the esophagus resulting in scarring. Scleroderma

• structural= something physically causing the problem

3.  May complain of choking, coughing, or sensation of food stuck in their throat/chest

Dysphagia

What disorder of the esophagus is being described?

• Backward movement of gastric contents into the esophagus.

• Most common disorder of the GI tract and seldom causes more serious problems

• The lower esophageal sphincter regulates the flow of food from the esophagus to the stomach.

• Causes pyrosis (“heartburn”)

• Meals high in fat increase the frequency of relaxation. (Of lower esophageal sphincter)

• Very common in infants- usually resolves by 2 years of age.

Gastroesophageal Reflux

“Gastro” = stomach; “Esophageal” = esophagus; “Reflux” = Backward movement

in Gastroesophageal Reflux Meals high in fat increase the frequency of relaxation (Of lower esophageal sphincter)

true

What is being described?

• Definition: Symptoms or mucosal damage from the reflux of gastric contents into the esophagus, oral cavity (including the larynx), and/or lungs.

• Acidic gastric fluids have a pH < 4.0 and are very damaging.

• More serious and longer lasting than GER and may lead to more serious problems. GER that occurs > twice a week for a few weeks may be GERD.

Gastroesophageal Reflux Disease (GERD)

What are manefestations of Gastroesophageal Reflux Disease (GERD)

• Pyrosis(heartburn, burning in chest) and regurgitation(feeling of food going back up and coming back down)

• Symptoms are usually worse 30 – 60 minutes after eating

• Usually made worse by bending at the waste and laying down.

• Often occurs at night

• Belching

• “Chest pain”

• May produce respiratory symptoms: asthma, chronic cough, laryngitis

  • the acid may irritate the upper airway

What are complications of GERD

•   Metaplasia(change in cell type) of the cells in the lower portion of the esophagus

  •   Over time they have had reflux ,now the cells in esophagus may resemble stomach cells so they can handle the acid

• Associated with the development of esophageal adenocarcinoma

What is being decribed

• 1% of all diagnosed cancers

• More common in adults > 65 years old

• Men > women

• Prognosis is poor- Usually it has already metastasized by the time the diagnosis is made.

• Two types: Squamous cell carcinoma and Adenocarcinoma

Cancer of the Esophagus

What desceribes Squamous cell Cancer of the Esophagus

• most common

• mostly attributed to alcohol and tobacco use

What desceribes adenocarcinoma Cancer of the Esophagus

•    Incidence is increasing

• Risk factors are Barrett esophagus and GERD

Manefestations of Cancer of the Esophagus (types: adenocarcinoma and squamous cell)

• Progressive dysphagia  

• Unintentional weight loss

• Anorexia

• Fatigue

• Pain when swallowing

Disorders of the stomach

• Gastritis

• Chronic Gastritis

• Peptic Ulcer Disease

  • peptic ulcers

    • duodenal ulcer

    • gastric ulcer

  •     Zollinger-Ellison Syndrome

  • stress ulcers

• stomach cancer

What is the Reservoir for contents entering the gastric tract.

stomach

stomach does what

• Food is churned, mixed with hydrochloric acid and pepsin before being released into the small intestine

• Gastric mucosal barrier of the stomach protects the lining from the damaging effects of the hydrochloric acid and pepsin.

 

What is the

Inflammation of the gastric mucosa(stomach lining)

gastritis

   Factors protecting the gastric mucosa (The Gastric Mucosal Barrier):

• Tight-fitting, impermeable epithelial cell surface covering

• Thick mucous secreted by cells

• Mucous secretes bicarbonate, neutralizing gastric pH

• Prostaglandins- Improve mucosal blood flow, decrease acid secretion, increase bicarbonate ion secretion, enhance mucous production

  • Increases blood flow to stomach and GI tract

What ..

• Improves mucosal blood flow, decrease acid secretion, increase bicarbonate ion secretion, enhance mucous production

  •   Increases blood flow to stomach and GI tract

 

Prostaglandins

What are some Factors that may cause gastric irritation:

a.     Certain medications (ex: Aspirin, NSAIDS)

b.     Alcohol

c.     Bile acids

d.     Decreased gastric blood flow

ex:    If SNS is being overly stimulated, we are not going to get good blood flow

a.     Acidosis (Metabolic & respiratory)

What is being descibred

a.   Characterized by an acute inflammatory process

b.  Usually a transient, self-limiting(run its course) disorder that resolves after causative agent is removed   

acute gastritis

Causes of acute gastritis?

• Most commonly associated with local irritants (meds such as aspirin or other NSAIDs, alcohol, or bacterial toxins)

• Serious illness or trauma accompanied by profound physiologic stress

• Uremia

• Chemotherapy and gastric radiation

Manefestation of acute gastritis

   i.     Emesis (mild to severe)

   ii.     Pain – heartburn or “sour stomach”

  iii.     Hemorrhage and ulceration (severe cases)

What is Chronic Gastritis

• No visible erosions

•   Characterized by chronic, inflammatory changes- atrophy of the epithelial cells of the stomach.

•    Three types: H. pylori; metaplastic atrophic gastritis; chemical gastropathy

What is Helicobacter pylori Gastritis

• H. pylori = most common cause of chronic gastritis

• Some people with H. pylori infection never develop clinical disease

• Chronic inflammation of the antrum and body of stomach

Pathogenesis of Helicobacter pylori Gastritis

• H. pylori colonize the mucus-secreting epithelial cells of the stomach

• Bacteria produce enzymes and toxins that interfere with the production of gastric mucosa, produce intense inflammation, and initiate an immune response

What is Chronic Atrophic Gastritis

• May be caused by multiple factors (H. pylori, environmental factors, diet)

• May be autoimmune (10% of cases)

• Usually causes few symptoms

What is Chemical Gastropathy

•    Chronic injury resulting from:

  •   Duodenal contents

  •   Pancreatic secretions

  • Bile

• More commonly seen with certain surgeries or other diseases

What is the term used to describe a group of ulcerative disorders in the upper GI tract that are exposed to acid-pepsin secretions

variety of causes: medications, H. pylori, disease processes, etc.

petic ulcer

What is being described

a.     May affect one or all layers of the stomach or duodenum

• May even penetrate the outer wall of the stomach or duodenum

b.     Spontaneous remissions and exacerbations

•   Regenerated, scarred mucosal tissue is not as good as the original tissue, which leads to repeated ulcerations

•   Ex: Ppl with this disease it will slightly heal, they will get sick with something else and it will flare up

c.     Most common types- Duodenal and gastric ulcers

peptic ulcers

·      Five times more common

·      Peak age: 30-50 years old

·      Males > Females

what kind of ulcer is being described above

duodenal ulcer

Less common

Middle-age to older adults

Equally distributed between men & women

what kind of ulcer is being described above

gastric ulcer

What is the Etiology & Pathogenesis of peptic ulcers

•     H. pylori-

  • Bacteria induces inflammation→Inflammation of the stomach increases acid production → Mucosal damage occurs

• NSAIDs-

  • Inhibition of prostaglandin synthesis

• Other factors that augment the effects of H. pylori and NSAIDs:

  • Advancing age

  •   Prior history of peptic ulcer

  •  Multiple NSAID use

  • Use of Warfarin (anticoagulant) along with corticosteroids

manifestations of peptic ulcers

•  Burning, gnawing, cramp-like pain, in midline

• Pain is relieved by food or antacids

• Usually rhythmic- between meals when the stomach is empty and between 1:00am – 2:00am

• Location- small area, midline, near the xiphoid process and may radiate to the costal margins, back, or right shoulder

• Pain may recur periodically at intervals of weeks to months and occur daily for several days and then remits

location of pain for peptic ulcers

small area, midline, near the xiphoid process and may radiate to the costal margins, back, or right shoulder

Complications of peptic ulcers

• Hemorrhage

  •   Hematemesis or melena

• Perforation and penetration

  • 1.     Significant mortality rate with perforation(poke a hole a stuff leaks our)

    2.     If ulcer penetrates, it penetrates another organ nearby

• Gastric outlet obstruction

  • 1.     Interference of the passage of gastric contents.

    2.     Caused by edema, spasm, or scar tissue

     

What is being described

Rare

Gastrin-secreting tumor (gastrinoma)- increase in gastric acid secretions leads to GERD or PUD

  Manifestations are similar to peptic ulcer. Diarrhea may also occur.

  Zollinger-Ellison Syndrome (one of the peptic ulcer diseases)

What do Gastrin-secreting tumor (gastrinoma) do

increase in gastric acid secretions leads to GERD or PUD(peptic ulcer disease)

Whatb is being described?

• GI ulcerations related to major physiologic stress

  • Severe illness

•   Major problem for hospitalized patients (especially the critically ill)

•    Results from ischemia to the mucosal tissue and alterations in the mucosal barrier

• prevented with medication

stress ulcers

What are risk factors of stress ulcers

• Large surface area burns (called Curling ulcer)

• Trauma

• Sepsis

• Acute respiratory distress syndrome

• Severe liver failure

• Major surgical procedures

• Intracranial injury (Cushing ulcer)

NEED PREVENTATIVE MEDICATIONS

What is being described

• 5^th most common cancer worldwide

• Most common in East Asia and Eastern Europe

• Males 2x > Females

1.     Gastric ulcers tend to be irregularly shaped, large, and have irregular margins

cancer of the stomach

What are risk factors of stomach cancer

•  Genetics

•  Carcinogenic(cancer causing) factors in the diet (smoked and preserved foods)

• Autoimmune gastritis

•  Gastric adenomas or polyps

• Possibly chronic H. pylori infection

Manefestations of stomach cancer

a.     Often asymptomatic until later stages

b.     Early stomach cancer signs: 

•  Indigestion or burning sensation

• Loss of appetite

• Abdominal discomfort

c. later signs   (enlarged, invaded tissue):

• weakness

• fatigue

• bloating after meals

• abdominal pain in upper abdomen

• weight loss

• hematemesis or melena (leading to anemia)

• dysphagia (tumor has invaded the esophagus)

Manefestations

Early stomach cancer signs:

•  Indigestion or burning sensation

• Loss of appetite

• Abdominal discomfort

Manefestaitions

later signs of stomach cancer  (enlarged, invaded tissue):

• weakness

• fatigue

• bloating after meals

• abdominal pain in upper abdomen

• weight loss

• hematemesis or melena (leading to anemia)

• dysphagia (tumor has invaded the esophagus)