Digestive system

Anorexia

A lack of desire to eat despite physiologic stimuli that would normally produce hunger

associated with nausea, abdominal pain, diarrhea, psychological stress, and weight loss

Causes linked to inflammation, neural signaling, mechanical issues, and or psychological factors

Vomiting (emesis)

several types of stimuli to cause it

Symptoms of this are hypersalivation and tachycardia

reverse peristalsis has to occur

abdominal muscles have to contract

Nausea

subjective experience that is associated with a number of conditions

Retching

non productive vomiting

projectile vomiting

spontaneous vomiting that does not follow nausea or retching

Constipation

defined as infrequent or difficult defication

Primary constipation

normal transit- chronic idiopathic

slow transit- enteric nerve dysfunction

pelvic floor or outlet dysfunction

Secondary constipation

caused by many different factors such as diet, medications, various disorders and aging

Diarrhea

presence of loose watery stools can be acute or persistent

Large volume diarrhea

caused by excessive amounts of water or secretions or both in the intestines

Small volume diarrhea

volume of feces is not increased, usually results from excessive intestinal motility

Osmotic diarrhea

due to osmotic balance issues increased solutes in the poop making less water move out oof the poop

Inflammatory diarrhea

water an other nutrients cannot pass through the intestinal wall as they normally would

Abornomal Gi motility

contents move through the intestines too quickly for normal water absorbtion to occur

Secretory diarrhea

epithelial cells secrete more water than they absorb

Systemic effects of diarrhea

dehydration, electrolyte imbalace, weight loss

Osmotic gap

stool osm value compared to sodium and potassium in the stool

High osmotic hap- osmotic diarrhea

Low gap- secretory diarrhea

Abdominal pain

usually associated with tissue injury and inflammation

Can be visceral, parietal and referred

Upper GI bleeding

esophagus, stomach or duodenum bleeding the blood is usually black or tarry (melena)

Lower GI bleeding

jejunum, ileum, colon, or rectum. Usually bright red in color (bright red stools)

Occult bleeding

not visible blood in feces and can be tested in order to determine where the blood is occuring

Fecal occult blood test

detects hidden blood in the stool using a chemical called guaiac

dysphagia

difficulty swallowing can be due to mechanical obstruction like a stricture or esophageal cancer

Functional disorders like neurological issues or peristalsis disorders

Hiatal hernia

diaphragmatic hernia with protrusion of the upper part of the stomach through the diaphragm and into the thorax

GERD

reflux of acid and pepsin from the stomach to the esophagus that causes esophagitis

Resting tone of the LES is lower than normal

Conditions that increase abdominal pressure or delay gastric emptying can contribute to this

Barretts esophagus and increased risk of esophageal cancerDi

Diagnosis of barrets’s esophagus

upper endoscopy

Pyloric obstruction

the blocking or narrowing of the opening between the stomach and duodenum can be acquired or congenital

Manifestations of pyloric obstruction

epigastric pain and fullness

nausea and vomiting

succussion splash

with a prolonged obstruction, malnutrition, dehydration and extreme debilitation

Intestinal obstruction

any condition that prevents the flow of chyme through the intestinal lumen

Simple obstruction of intestine

mechanical blockage of the lumen

Functional obstruction of the intestines

failure of intestinal motility

often occurs after intestinal or abdominal surgery, pancreatitis or hypokalemia

Signs of small intestinal obstruction

colicky pains, nausea, and comiting

Signs of large intestine obstruction

hypogastric pain and abdominal distention

Gastritis

inflammation of the gastric mucosa can be acute and chornic

Acute gastritis

caused by injury of the protective mucosal barrier

Chronic gastritis

based on if it is caused by H. pylori or serum pepsinogen levels

Symptoms of gastritis

very vague but anorexia, fullness, nausea, vomiting, epigastric pain

Peptic ulcer disease

a break in ulceration in the protective mucosal lining

usually in stomach or proximal duodenum

sometimes in the esophagus

Developmental factors of peptic ulcer disease

helicobacter pylori infection or the use of NSAIDs

Stress ulcers

acute form of peptic ulcer that is related to severe illness or major traumaI

Ischemic ulcers

reduced blood flow to stomach occurring within hours of trauma, burns, hemorrhage, heart failure, or sepsis

Curling ulcers

caused by reduced plasma volume following burn injury

Cushing ulcers

brain injury, or brain surgery causes vagus nerve overstimulation, increased acid production

Maldigestion

failure of the chemical processes of digestion

Malabsorbtion

failure of the intestinal mucosa to absorb digested nutrients

Usually occurs with malabsorbtion

Exocrine pancreatic insufficiency (EPI)

insufficient pancreatic enzyme production such as lipase, amylase, trypsin, or chymotrypsin

Causes: pancreatitis, pancreatic carcinome, pancreatic resection, cystic fibrosis

Fat maldigestion- main symptoms fatty stools and weight loss.`

Lactose intolerance

inability to break down lactose preventing lactose digestion and absorption

fermentation of lactose by bacteria causes gas and osmotic diarrhea

Ethnic variability in lactase persistence

Bile Salt deficiency

conjugated bile salts needed to emulsify and absorb fats

bile salts are conjugated in the bile that is secreted from the liver

can result from liver disease and bile obstructions

Symptoms of bile salt deficiency

poor intestinal absorption of lipids causes fatty stools (steatorrhea) diarrhea, and loss of fat solubleI vitamins (A,D,E,K)

IBS

Risk factors- genetic and eniromental, malfunctions in the epithelial cell barrier that lines the GI tract abnormal immune response to normal intestinal barriers

Signs and symptoms: abdominal pain, diarrhea, bloody stools, weight loss

Diagnosis: endoscopy

Pathophys: crohns-inflammation spreads through the entire GI tract and each layer of the lining this results in granulomas

Ulcerative colitis: inflammation spreads through the large intestine, starting with the rectum and involves only the muscosal layer, ulcers will form and necrosis of the mucosal layer will occur leading to blood in the stool

GERD

Risk factors: mitral herna, pregnancy, obesity, smoking, esophageal stenosis, scleroderma, and medications

Pathophys: the lower esophogeal sphincter, separates the esophagus and the stomach, When the LES is weakened it can lead to its unwanted relaxation allowing passage of stomach acid irritating the esophagus

Signs and symptoms: Backwash or regurgitation, burning sensation, non-cardiac chest pain, nausea, sore throat and asthma symptoms.

Celiac Disease

Pathophys: autoimmune disease dysfunction that attacks the small intestine specifically the villi leading to malabsorption of nutrients

Complications: malnutrition, bone weakening, lactose intolerance, cancer, nervous system conditions

Signs and symptoms: diarrhea, abdominal pain, nausea, constipation, weight loss, bloating and gas, fatigue. A

Appendicitis

pathophysiology: blackages of the appendix by stool or cancer that cause inflammation and infection of the appendix

Signs and symptoms: sudden lower right abdominal pain, nausea and vomiting, constipation or diarrhea

Complication: peritonitis and explosion of the appendix

Inflammatory bowel disease

ulcerative colitis, Crohns disease, microscopic colitis chronic, relapsing ibs disorders

Causes of IBS

Genetics, environmental factors, alterations of epithelial barrier functions, altered immune reactions to intestinal flora.

Ulcerative colitis

chronic inflammatory disease that causes ulceration of the colonic mucosa

begins in the rectum, extends to sigmoid colon and may extend entire colon

Symptoms: diarrhea, urgency, bloody stools, crampin

Crohns disease

granulomatous colitis, leocolitis, or regional enteritis, idiopathic inflammatory disorder; affects any part of the digestive tract, from mouth to anus

Can produce fissures that extend into lymphatic

anemia may result from malabsorbtion of vitamin B12 and folic acid

Differences between ulcerative colitis and Crohns

Chrons is very diffuse and ulcerative colitis is limited to large intestine and colon

Microscopic colitis

relatively common cause of nonblood diarrhea results in chronic daily watery diarrhea

Diverticula

Herniations of mucosa through the muscle layers of the colon wall, especially the sigmoid colon

Diverticulosis

Asymptomatic diverticular diases

Diverticulitis

the inflammatory stage of of diverticulosis

Appendicitis

inflammation of the vermiform appendixC

Causes of appendicitis

obstruction, foreign bodies, infection

Complications of appendicitis

perforation, peritonitis, and abscess formation are the most serious complications

Symptoms of periumbilical pain

rebound tenderness to right lower quadrant

Portal hypertension

abnormally high blood pressure in the portal venous system caused by resistance to portal blood flow

can be intrahepatic- within the liver

posthepatic- after liver

Complications of portal hypertension

varices, splenomegaly, hemorrhoids, ascites

Ascites

Accumulation of fluid in the peritoneal cavity

Most common causes of cirrhosis

What causes development of ascites

portal hypertension, decreased synthesis of albumin by the liver, splanchnic vasodilation, renal sodium and water retention

Complications of ascites

25% mortality in 1 year if associated with cirrhosis

causes abdominal distention and increased abdominal girth and weight gain

paracentesis

Hepatic encephalopathy

a neurologic syndrome of impaired behavioral, cognitive, and motor function

Develops rapidly during fulminant hepatitis or slowly with liver disease

CNS is vulnerable to neurotoxinsJ absorbed from the GI tract that are not metabolized by liver and therefore circulate to the brain.

Jaundice

caused by hyperbilirubinemia

obstructive jaundice

cannot remove bilirubin

extra or intra hepatic obstructions

Hemolytic jaundice

too much bilirubin

prehepatic jaundice or excessive hemolysis of red blood cellS

Symptoms of jaundice

dark urine, yellow skin and sclera and light colored stools

Hepatorenal syndrome

functional renal failure that develops as a complication of advanced liver diseaseC

Caused of hepatorenal system

Caused by a lack of blood flow to the glomerulus, causing increased renin and activation of renin angiotensin system

causes vasoconstriction of the kidneys vessels, worsening disease

Acute liver failure

rare clinical syndrome resulting in severe impairment or necrosis of liver cells without preexisiting liver disease or cirrhosis

Complications of acute liver failure

liver dysfunction, hepatic encephalopathy, coagulopathy, ascites, jaundice

Cirrhosis

irreversible inflammatory, fibrotic liver disease

biliary channels become obstructed and cause portal hypertension

severity depends on cause C

Causes of cirrhosis

hepatitis C and alcohol abuse

Alcoholic liver disease

toxic effects of alcohol and coexisting liver disease

Alcoholic steatosis

Alcoholic steatohepatitis

alcoholic cirrhosis

Nonalcoholic fatty liver disease

infiltration of hepatocytes with fat occuring in the absence of alcohol intake

may progress to nonalcoholic steatohepatitis, which may progress to cirrhosis and end-stage liver diseaseR

RISK factors for NAFLD

Type 2 diabetes, gastric bypasses, insulin resistance, obesity

Viral hepatitis

systemic viral disease that primary affects the liver can cause acute, icteric illness

manifestations of viral hepatitis

spectrum of manifestations ranges from absence of symptoms to acute liver failure, with rapid onset of liver failure and coma

Gallstones

formed from impaired metabolism of cholesterol, bilirubin, and bile acids

Cholestrol gall stones

formed from biles that is supersaturated with cholesterol produced by the liver

mixed gall stones

formed from calcium bilirubinate and fatty acid soaps that bind with calcium

pigment gall stones

composed of calcium bilitubinate with mucin glycoproteins

Cholecystitis

inflammation of the gall bladder or cystic duct usually caused by a agallstone lodged in the cystic duct

Pancreatitis

inflammation of the pancreas

Acute pancreatitis

usually mild and resolves spontaneously

may result from gallstone blockage or direct cellular injury from alcohol drugs or viral infection

Chronic pancreatitis

progressive fibrotic destruction of the pancreas

related to chornic alcohol abuse

continuous or intermittenet abdominal pain and weight loss are common

risk factor for pancreatic cancer

Esophagus cancer

symptoms include chest pain and dysphagia

squamous cell carcinoma in esophagus

associated with smoking tobacco and chronic alcohol consumption

Adenocarcinoma in esophagus

associated with obesity, GERD and smoking tobacco

Stomach cancer

early symtpoms are vague, loss of apetite, malaise, indigestion

associated with atrophic gastritis and H pylori

Colon and rectal cancers

caused by multiple gene alterations and environmental interactions

symptoms depend on location, size and shape