Patho GI need to knows

cajal cells

specialized cells in the gastrointestinal tract that act as pacemakers, generating slow waves that drive muscle contractions to move food through the digestive system

Is the following statement true or false?

Gastrointestinal hormones function in the digestive tract to facilitate the absorption of essential nutrients

False

Rationale: The hormones stimulate gland that will directly secrete enzymes into the digestive tract

gastric mucosal barrier

impermeable epithelial cell surface covering

One of the important characteristics is resistance to the highly acidic secretions that it produces.

It also protects the stomach from pepsin

Is the following statement true or false?

Bacteria are an essential component of the digestive tract

True

Rationale: They serve very important physiological functions, such as protection from invasive species

Which of the following is an accurate statement regarding digestion and absorption?

A.Digestion involves movement of materials through the gastrointestinal tract at a rate that facilitates absorption.

B.The regulation of secreted enzymes is controlled by the hypothalamus via trophic hormones.

Digestion is the active transport of proteins, carbohydrates, and fats into the blood stream

A. Digestion involves movement of materials through the gastrointestinal tract at a rate that facilitates absorption

anorexia

loss of appetite. Appetite is influenced by hunger which is stimulated by contractions of the empty stomach. The hypothalamus and other associated centers in the brain regulate appetite or the desire for food intact. 

nausea

an ill-defined and unpleasant subjective sensation. It is the conscious sensation resulting from the stimulation of the medullary vomiting center that often precedes or accompanies vomiting

A common cause of nausea is distention of the duodenum or upper small intestinal tract, and can be accompanied by autonomic nervous system symptoms such as watery salivation, vasoconstriction with pallor, sweating and tachycardia.

major causes of gastric irritation

Aspirin/NSAID use and H. pylori

vomiting

Protective response to expel noxious agents from the GI tract

involves two functionally distinct medullary centers—the vomiting center and the chemoreceptor trigger zone

which cranial nerves are involved in swallowing?

V, IX, X, XII

dysphagia

difficulty swalling

can be from stroke involving the cranial nerves involved in swallowing, cancer, scleroderma (autoimmune disorder) 

odynophagia

painful swallowing

achalasia

failure of esophageal sphincter to relax, resulting in difficulty passing food into the stomach

pt is at risk for aspiration when they lay down

Which of the following does not involve an alteration in the esophagus or swallowing?

A.Dysphagia

●

B.Odynophagia

●

C.Achalasia

●

D.GERD

D. GERD

Rationale: GERD refers to the backward movement of gastric contents into the esophagus or beyond, into oral cavity or lung. This condition causes heartburn or pyrosis. Dysphagia produces narrowing of the esophagus and difficulty swallowing. Odynophagia is pain on swallowing food or fluids and may be associated with disorders of the esophagus. Achalasia occurs when the lower esophageal sphincter fails to relax due to a disruption in the input from the enteric neural plexus and the vagus nerve

gastroesophageal reflux

refers to the backward movement of gastric contents into the esophagus. It probably is the most common disorder originating in the GI tract

Relaxation of the lower esophageal sphincter is a brain stem reflex that is mediated by the vagus nerve in response to a number of different stimuli. Transient relaxation with reflux is common after meals

*MI can present as heart-burn like symptoms

diverticulum

a protruding pouch in the lining of the esophagus that forms in weakened areas of the muscular layer of the esophagus

Mallory-Weiss Syndrome

longitudinal tear in the esophagus

what is squamous cell carcinoma of the esophagus related to?

alcohol and tobacco use

what is adenocarcinoma of the esophagus related to?

Barrett esophagus and GERD

s/sx of esophageal cancer

Dysphagia

Weight loss

Anorexia

Fatigue

Painful swallowing

Not easily caught

*progressive dysphagia (difficulty swallowing) is the most frequent complaint, but this is a late sign of the disease, with poor prognosis

Barrett’s esophagus

complication of GERD where lining of the esophagus heals abnormally

the presence of the tan tongues of epithelium interdigitating with the more proximal squamous epithelium is typical of Barrett esophagus

major causes of gastric irritation and ulcer formation

-aspirin/NSAIDS

-alcohol

-H. pylori

-bile acids

acute gastritiis

inflammation may be accompanied by emesis, pain, and in severe cases hemorrhage and ulceration.  This erosive form is an important cause of acute GI bleed.   Its usually from local irritants, ASA, ETOH 

chronic gastritis

no visible erosions,  there is chronic inflammatory changes leading to atrophy of the glandular epithelium of the stomach

H. pylori is the most common cause

-The bacteria produce enzymes and toxins that interfere with the protection of the gastric mucosa against acid and produce an intense inflammatory response and an immune response

NSAIDs and aspirin contribute to the formation of gastritis by inhibiting the _____________.

A.immune system

●

B.production of acid

●

C.synthesis of prostaglandins

●

D.production of mucus

C. synthesis of prostaglandins

Rationale: The synthesis of prostaglandins is decreased due to the anti-inflammatory action of the drugs; therefore, acid production is unregulated

how do we test for H. pylori infection?

C urea breath test

tx requires antibiotics and PPIs

causes of peptic ulcer formation

decreased mucosal protection and increased acid production. 

H. Pylori and use of ASA/NSAIDs

alcohol & tobacco

complications of peptic ulcer

hemorrhage

obstruction

perforation

risk factors for development of stress ulcers

*Large surface area burns

Trauma

Sepsis

Acute respiratory distress syndrome

Severe liver failure

Major surgical procedures

Zollinger-Ellison syndrome

most common cause of bacterial infection in the intestines

E. coli

characteristics of IBD

Persistent or recurrent symptoms of abdominal pain

Altered bowel function

Varying complaints of flatulence, bloatedness

Nausea and anorexia

Constipation or diarrhea

Anxiety or depression

Crohn’s Disease

oA recurrent, granulomatous type of inflammatory response that can affect any area of the gastrointestinal tract from the mouth to the anus

patchy areas of inflammation of cobblestone appearance

usually affects ppl in their 20s and 30s, women more than men

Ulcerative Colitis

nonspecific inflammatory condition of the colon

-rectal bleeding and development of cancer are common

-peak incidence is 15-25 years old

s/sx of diverticulitis

food gets trapped in the diverticulum

-Pain in the lower left quadrant

-Nausea and vomiting

-Tenderness in the lower left quadrant

-A slight fever

-An elevated white blood cell count

s/sx of appendicitis

Abrupt onset with epigastric or periumbilical pain.  There can be nausea, RLQ pain and increased WBCs and a fever (but not always), rebound tenderness

manifestations of celiac disease

oFailure to thrive

oDiarrhea

oAbdominal distention

oOccasionally, severe malnutrition

common causes of constipation

Failure to respond to the urge to defecate

Inadequate fiber in the diet

Inadequate fluid intake

Weakness of the abdominal muscles

Inactivity and bed rest

Pregnancy

Hemorrhoids

causes of fecal impaction

Painful anorectal disease

Tumors

Neurogenic disease

Use of constipating antacids or bulk laxatives

A low-residue diet

Drug-induced colonic stasis

Prolonged bed rest and debility

causes of peritonitis

Perforated peptic ulcer

Ruptured appendix

Perforated diverticulum

Gangrenous bowel

Pelvic inflammatory disease

Gangrenous gallbladder

Abdominal trauma and wounds

can be life-threatening bc it can spread very quickly

intestinal malabsorption definition and causes

Failure to transport dietary constituents from the lumen of the intestine to the extracellular fluid

Causes

-Celiac disease

-Inflammatory reaction

-Neoplasm

-Colorectal cancer

intestinal malabsorption symptoms

oDiarrhea

oSteatorrhea (fat in the stool)

oFlatulence

oBloating

oAbdominal pain

oCramps

oWeakness, muscle wasting

oWeight loss and abdominal distention

function of the liver

oSynthesizes glucose, plasma proteins, and blood clotting factors

oCarbohydrate, protein, and fat metabolism

-Storage of mineral and vitamins

-cholesterol metabolism

oIs responsible for the degradation and elimination of drugs and hormones

-Elimination of bilirubin

-Metabolism of steroid hormones

-Metabolism of drugs

Filtration of blood and removal of bacteria

Production of bile salts

function of the pancreas

oSupplies the insulin and glucagon needed in cell metabolism

jaundice

yellowish discoloration of the skin and deep tissues from abnormally high levels of bilirubin in the blood.

occurs when there is an imbalance between the synthesis of bilirubin and the clearance of bilirubin

prehepatic jaundice

major cause is excessive hemolysis of red blood cells

unconjugated bilirubin (waste product of hemoglobin – it needs to be converted into conjugated bilirubin to be removed)

intrahepatic jaundice

oCaused by disorders that directly affect the ability of the liver to remove bilirubin from the blood or conjugate it so it can be eliminated in the bile

oConjugated bilirubin

posthepatic bilirubin

oOccurs when bile flow is obstructed between the liver and the intestine

oConjugated bilirubin

Which of the following is not a cause of jaundice?

A.Excessive destruction of red blood cells

B.Impaired uptake of bilirubin by the liver cells

C.Ingestion of iron supplements

D.Decreased conjugation of bilirubin

E.Obstruction of bile flow in the canaliculi of the hepatic lobules or in the intrahepatic or extrahepatic bile ducts

C. Ingestion of iron supplements

Rationale: Ingestion of iron supplements does not affect the metabolism of RBCs

where are most drug metabolizing enzymes located?

the lipophilic membranes of the smooth endoplasmic reticulum of liver cells

Hepatitis A

a small single stranded ribonucleic acid virus.  Usually self limiting, - virus replicates in the liver and is excreted in the bile and shed in the stool

Hepatitis B

a double stranded deoxyribonucleic acid (DNA) virus. 

can produce acute or chronic hepatitis, and can progress to cirrhosis -  found in most body secretions, and can be spread by oral or sexual contact.

High prevalence in drug uses, heterosexuals with multiple partners, and men who have sex with men.  Health care workers are at risk due to blood and fluid exposure, and needlesticks

Hepatitis C

Single stranded RNA Virus.  2% of people in US have Hep C – IV drug use, High risk sexual behavior or Hep C+ partner, actively infected mothers to infants.  Some people who become infected can clear the virus, but 80% go on to develop chronic hepatitis.  Hep C causes progressive liver fibrosis leading to cirrhosis, end-stage liver disease and cancer

Is the following statement True or False?

Hepatitis is caused by viral insertion into the host cell genome resulting in death of the cell

False

Rationale: Some forms of hepatitis are caused by viruses, but not all. For example autoimmune-, drug-, fatty-, and alcohol-induced hepatitis

what occurs during metabolism of alcohol?

injury of cells in the liver

early symptoms of intrahepatic biliary disease

oUnexplained pruritus or itching

oWeight loss

oFatigue

late symptoms of intrahepatic biliary disease

oDark urine and pale stools

oJaundice

cirrhosis

Much of the liver tissue has been replaced with fibrous tissue, usually associated with alcoholism but can be related to viral hepatitis, toxic reactions to drugs and chemicals, biliary obstruction, and NAFLD

manifestations of cirrhosis

Weight loss (sometimes masked by ascites), Anorexia

Weakness

Diarrhea or constipation, Abdominal pain

Hepatomegaly (enlarged liver), Splenomegaly

Jaundice

Portal hypertension, Esophageal varices

Ascites

purpura

fetor hepaticus (strong musty smelling breath)

manifestations of liver failure

Hematologic disorders (decreased coagulation factors, can lead to bleeding)

Endocrine disorders (Disorders of synthesis and storage of glucose, proteins, lipoprotein cholesterol, bile salts.  Result in hypoglyemic events, hypoalbuminemia)

Skin disorders

Hepatorenal syndrome

Hepatic encephalopathy (Affects amino acids (this causes impairment of conversion of ammonia to urea → lead to encephalopathy))

decreased cholesterol and impaired fat absorption

portal hypertension

Increased resistance to flow in the portal venous system and sustained portal vein pressure.  -  can be caused by obstructions.

Complications are ascites, splenomegaly, hepatic encephalopathy, esophageal varices

where does hepatocellular carcinoma arise from?

liver cells

where does cholangiocarcinoma arise from?

bile duct cells

what do the left and right hepatic ducts come together to form?

common hepatic duct

which duct extends to the gallbladder?

cystic duct

what is the common bile duct?

formed by the union of the common hepatic duct and the cystic duct

what are gallstones primarily made of?

cholesterol

what are the two primary factors that contribute to gallstone formation?

abnormalities in the composition of bile (particularly increased cholesterol)

bile stasis

cholelithiasis

gallstones

cholecystitis

inflammation of the gallbladder

cholangitis

inflammation of the common bile duct

common causes of acute pancreatitis

Gallstones (stones in the common duct)

Alcohol abuse

Hyperlipidemia

Hyperparathyroidism

Infections (particularly viral)

Abdominal and surgical trauma

Drugs such as steroids and thiazide diuretics

what is a major risk factor for pancreatic cancer?

smoking (#1)

diet

Which of the following organs is directly responsible for the elements of cholelithiasis?

A.Liver

●

B.Gallbladder

●

C.Pancreas

●

D.Biliary tree

A. Liver

Rationale: The liver is responsible for metabolizing cholesterol

BMI ranges

<18.5 is underweight

>25 is considered overweight

>30 is considered obese

>40 is morbid obesity

Adipocytes

Adipocytes contain 90% of body energy

health risks associated with obesity

Hypertension

Hyperlipidemia

Type 2 diabetes

Coronary heart disease

Other health problems

upper body obesity

central, abdominal, or male obesity

cardiometabolic risk

lower body obesity

peripheral, gluteal-femoral, or female obesity

medical complications of obesity

cerebral atherosclerosis, stroke

hypoventilation

hypertension, LVH, coronary artery atherosclerosis, MI

diabetes

gallstones

osteoarthritis

hyperlipoproteinemia

Kwashiorkor-like secondary protein-energy malnutrition 

 occurs in acute illnesses, trauma, burns, and sepsis

may have:

-muscle wasting

-growth failure

-fatty liver

-irritability

-atrophy of small intestine, diarrhea

-depigmentation of skin, dermatoses

-edema

Marasmus-like secondary protein–energy malnutrition

occurs in chronic illness, like COPD, CHF, cancer, and HIV

Is the following statement True or False?

Anorexia is a genetic condition that can be treated with medication

False

Rationale: Anorexia is a severe psychological condition that must be addressed at the root cause. Medically, we can treat the symptoms, but the cause is rooted in mental state