Made Ridiculously Simple Flashcards
Acid secretion
Churning
Releases food to duodenum
Secretes intrinsic factor
Stomach
Digestion
Absorption
Small intestine
Water reabsorption
Passage of stool
Large intestine
Where do these occur?
Chron’s disease
Obstruction
Tumors
ANYWHERE in GI tract!
Where do these occur?
Obstruction
Reflux
Esophagitis
Varices
Esophagus
Where do these occur?
Ulcer
Gastroparesis
Outlet obstruction
Gastritis
Pernicious anemia
Stomach
Where do these occur?
Malabsorption
Obstruction
Mesenteric ischemia
Small intestine
Where do these occur?
Diarrhea
Constipation
Obstruction
Mesenteric ischemia
Colitis
Large intestine
This is made in the stomach and binds vitamin B12
Intrinsic factor
Loss of intrinsic factor can result in….
Pernicious anemia (because of decreased B12 absorption)
Is there any digestion or absorption in the esophagus?
NO
Obstruction
Dysfunction of the muscle or its innervation
Outpouchings (diverticula)
Inability to prevent stomach contents from re-entering esophagus
Problems that can occur in the esophagus
The esphagus will:
have decreased peristalsis
be unable to relax the lower esophageal sphincter to allow passage of food
….if what is compromised?
Parasympathetic input
*parasymp does “rest and digest”…tells GI system to do all digestion related things!
Esophageal ______ can occur in scleroderma or other connective tissue diseases, as well at in Chagas disease
Dilation
The lower esophageal sphincter remains constricted and is unable to relax
later in disease, there is also failure to constrict: the lower 2/3 of the esophagus lose the ability to peristalse
Achalasia
In this disease, a poorly understood process destroys postganglionic parasympathetic neurons of the esophagus
Achalasia
The constricted sphincter and proximal dilation classically resemble a birds beak on a barium swallow imaging
Achalasia
Outpouchings of the esophagus
Diverticula
Lies just behing the upper esophageal sphincter
It is an outpouching of the lumen that causes food and drink to get stuck there instead of continuing down
Bc food gets stuck, sometimes pts regurgitate
Zenker’s diverticulum
(regurgitation would be undigested, since it has not yet reached the stoamch)
MC disorder of esophagus
Backwash of stomach acid up through the lower esophageal sphincter, which burns the esophagel mucosa (esophagitis)
GERD
Heartburn, sour taste in mouth, chest pain
Typically worse when bending over ot when lying down after eating
GERD
A premalignant condition
Metaplasia from squamous epithelium to columnar
predisposes to adenocarcinoma
Barrett’s esophagus
GERD
Meds (ie chemo)
Radiation
Chron’s disease
Infection
..can all cause?
Esophagitis
2 types of esophageal cancer
Adenocarcinoma
Squamous cell carcinoma
Barrett’s esophagus predisposes to ___________
Smoking and alcochol predispose to ________
Barretts –> Adenocarcinoma
Smoking/alcohol —> Squamous cell carcinoma
Dilation of esophageal veins, usually caused by liver disease/portal HTN
Esophageal varices
These dilated vein walls are more fragile and they are under high pressure, making them easy to rupture…causing esophageal bleeding
Esophageal varices
What is the appearance of blood from an esophageal varice?
Bright red! (undigested)
*in contrast to digested blood (ie gastric or duodenal ulcers) which appears like coffee grounds
The _____ cells of the stomach secrete acid by pumping H+ into the stomach lumen in exchange for K+
*this mechanism is stimulated by gastrin, histamine and Ach
*this mechanism if inhibited by somatostatin, prostaglandins, secretin, and VIP
parietal
Gastrin
Histamine
Acetylcholine
..stimulate or inhibt acid production in stomach?
STIMULATE!
Somatostatin
Prostaglandins
Secretin
VIP (vasoactive intestinal peptide)
Stimulate or inhibit acid secretion in the stomach?
INHIBIT
2 basic pathophysiological causes of ulcer formation?
- decreased mucosal protection
- increased acid production
**H PYLORI LEADS TO ULCER FORMATION BY BOTH MECHANISMS
Prostaglandins (increase/decrease) mucus secretion in the stomach?
INCREASE
This drug class decreases mucus secretion because they block prostaglandin pathways
NSAIDs
..this can lead to ulcer formation
What do tobacco and alcohol do to mucosal protection in the stomach?
DECREASE! …predisposing to ulcers
Why do stress ulcers occur?
(due to sepsis, burns, hemorrhage, etc.)
Decreased perfusion to stomach can lead to decreased mucosal protection
Gastrin, produced by G cells, stimulates…..
acid secretion
In this syndrome…
a pancreatic tumor called a gastrinoma secretes excess gastrin
*the increase in gastrin secretion by the gastrinoma leads to increased acid production, causing ulcers
Zollinger-Ellison syndrome
This diagnosis can be provd by marked elevation in serum gastrin and by elevation fo serum gastrin in response to secretin
Zollinger-Ellison Syndrome
_______ is a hormone normally produced by the small intestine when food arrives from the stomach
*stimulates the pancreas to secrete bicarb, which neutralizes the duodenal contents
Secretin
SECRETIN NEUTRALIZES DUODENAL CONTENTS VIA BICARB
Secretin inhibits…..
Gastrin secretion
If a pancreas has a gastrinoma, secretin will do what to gastrin levels?
INCREASE
(gastrin will stimulate gastric acid production…ultimately leading to ulcer formation)
A positive secretin test (ie elevation of serum gastrin in response to secretin) is diagnostic for…..
Zollinger-Ellison Syndrome
Pain
N/V (with blood sometimes)
Melena
Changes in appetite
*if severe, can lead to perforation of the duodenal or gastric wall
Ulcers
These can present as acute abdominal pain with air under the diaphragm visible on XRay
Perforated ulcers
In which site would ulcer pain get worse immediately after eating?
Gastric ulcers
Which site would ulcer pain get worse some time after eating?
Duodenal ulcer
What diagnostic will definitively diagnose a gastric or duodenal ulcer?
Endoscopy
*gastric ulcers should ALWAYS be biopsied to rule out cancer
Which drug class…
Directly affect acid secretion by blocking H+/K+ pump in the parietal cells
PPIs
Which drug class….?
Decrease stimulation of the parietal cells by blocking histamine
H2 blockers
Where are H2 receptors located?
Parietal cells
How do Sucralfate and Misoprostol work?
They increase mucosal protection
*Misoprotol increase prostaglandins
*Sucralfate provides a coating
A condition in which antibodies form against the parietal cells, leading to loss of intrinsic factor (and therefor unable to absorb B12)
Pernicious anemia (aka autoimmune gastritis)
“from the inside” causes:
- foreign body
- gastric polyp
- gastric cancer
“from the outside” causes:
-pancreatic tumor
Obstruction causes of the pyloric sphincter
Symptoms of an obstructed pyloric sphincter?
Vomit!*
Early satiety
Abdominal distention
A palpable olive-like mass on exam and visible waves of peristalsis
…presentation of?
Congenital pyloric sphincter
(the “olive” mass is the hypertrophied sphincter)
Stomach is under the control of which nervous system?
Enteric Nervous System
Parasympathetic input to stomach comes from the Vagus Nerve.
A problem with parasympthetic nerves to stomac can lead to decreased stomach muscle activity and…..
Gastroparesis (paralysis of the stomach)
H. Pylori
Pernicious anemia
Radiation
…all predispose to?
Gastric cancer
MC type of gastric cancer
Adenocarcinoma
N/V
Early satiety
GI bleeds
Gastric cancer
..usually occur late in dz so prognosis generally poor
Food is churned and broken down in the stomach
then, arrives in small intestine which stimulates the release of what by the duodenum?
Cholecystokinin (CCK)
and
Secretin
What secretes CCK and Secretin? and when?
Secreted by the duodenum
..when food from the stomach reaches the small intestine
Most common part of the colon for diverticula?
Descending (LLQ)
If lactose is not broken down by lactase enzyme, it ends up in the lg intestine (instead of being absorbed in the small intestine)
*this increase in solute concentration in the lg intestine causes….
water to be drawn into the lumen —> diarrhea
Genetic
Abdominal pain
Lower GI bleeding
Change in bowel habits
and/or obstruction
Colon cancer (adenocarcinoma)
Regular screening of:
Fecal occult blood testing
Flexible sigmoidoscopy
Barium contrast Xray
and/or colonoscopy
..recomended for age?
50+
Which 2 conditions make up inflammatory bowel disease
Chron’s disease
Ulcerative colitis
Difference between ulcerative colitis and chron’s?
Ulcerative colitis is limited to colon and has continuous ulcerations
Chron’s can occur anywhere from mouth to anus and has interrupted, multiple ulcerations
Causes transmural inflammation (crossing histologic boundaries)
and fissures (boundary crossing tears)
Chron’s disease
Chron’s disease can cause what type of anemia?
B12 deficiency anemia
(from damage to terminal ileum, which decreases B12 absorption)
Aphthous ulcers
Sclerosing cholangitis (inflammation of bile ducts)
Skin findings (pyoderma gangrenosum, erythema nodosum)
Eye findings (iritis, scleritis)
Seen with inflammatory bowel disease
Can have inflammatory bowel disease increase your risk of colon cancer?
YES
If a pt vomits bright red blood, where must the bleed be coming from?
ABOVE the gastroesophageal sphincter/junction because this blood is NOT DIGESTED
If the pt vomits dark, “coffee ground” vomit, where must the bleed be coming from?
BELOW the gastroesophageal sphincter/junction because the blood has been digested
(typically a gastric or duodenal ulcer)
Causes of hematochezia (bright red blood in stool):
Bleeding hemorrhoids
Bleeding colon cancer
Bleeding diverticula
(bright red must mean close to exit)
Melena (dark, tarry stool) indicates a bleed where?
Upper GI bleed (has been digested)
ie bleeding ulcer
What vein drains the gut’s venous system, carrying absobed nutrients to the liver?
Hepatic portal vein
*Provides glucose during fasting (via gluconeogenesis and glycogenolysis)
*detoxifies
*stores glycogen
*produces bile and other proteins/lipids
Functions of the liver
If there is liver failured and a decreased ability to detoxify the blood, what can happen?
Toxins in blood can build up, leading to hepatic encephalopathy
If there is liver failure and a decrease in gluconeogenesis, what can happen?
Fasting hypoglycemia
If there is liver failure and a decrease in protein production, what can happen?
Decreased production of clotting factors, increasing the risk of bleeding
If there is liver failure, which prevents the liver from secreting conjugated bilirubin or from conjugating bilirubin, what can happen?
Jaundice!
______ emulsifies fats in the GI tract, facilitating their absorption
Bile
Bile is produced in the liver and then drains through the intrahepatic biliary system into the extra-hepatic……
biliary tree
A component of bile that is a product of the breakdown of old (or damaged) RBCs
Bilirubin
When RBCs break down, what type of bilirubin forms in circulation?
Unconjugated
(the liver conjugates this, making conjugated bilirubin!)
The liver turns the unconjugated bilirubin into conjugated bilirubin, which is secreted into the…
bile
Is jaundice due to an increase in conjugated or unconjugated bilirubin?
EITHER!
Unconjugated bilirubin is also called….
Indirect bilirubin
- increased production of bilirubin
- decreased uptake of bilirubin by the liver
- decreased conjugation of bilirubin by the liver
…will all cause an increase in?
Indirect bilirubin (and jaundice!)
What does hemolytic anemia do to bilirubin?
Increases production!
(bc bilirubin comes from the breakdown of old or damaged RBCs)
CHF reduces blood flow to the liver, which decreases delivery of bilirubing, resulting in….
unconjugated jaundice
Crigler-Najjar and Gilbert’s syndrome cause what kind of jaundice?
Unconjugated
If the liver cannot secrete bilirubin into the bile ducts or if the biliary tree is obstructed, what kind of jaundice?
Conjugated jaundice
Toxin induced hepatic failure or infections
Alcoholics
Autoimmune hepatitis
….cause what type of jaundice?
Conjugated bilirubin jaundice
An obstruction of the biliary tree causes what kind of jaundice?
Conjugated
In liver disease, which 2 enzymes are released into circulation?
AST
ALT
When the biliary tree is obstructed, the cell of the bile ducts release…..
alkaline phosphatase
(alk phos=obstruction)
…in long standing obstruction, AST and ALT may be elevated too, but not as much as alk phos
Alkaline phosphatase is mainly present in the cells of the….
bile ducts
(damage to the bile ducts will result in an increse of alk phos)
Injury to hepatocytes will result in elevation of?
AST and ALT
Which type of bilirubin is elevated in liver disease?
Conjugated
(secretion of bilirubin is a rate limiting step)
_______ is a serum protein synthesized by the liver
*used to measure the liver’s capacity for protein synthesis
Albumin
What happens to albumin levels in liver dz?
decrease
(albumin also decreases in inflammatory dz like trauma, malnutrition, and dzs that cause proteinuria)
_____________ measures function in part of the clotting cascade
prothrombin time
If there is liver damage and deficient clotting (due to liver disease) what happens to the prothrombin time?
elevated prothrombin time
if there is deficient clotting factors due to liver dz
Prothrombin time assesses the extrinsic pathway of the clotting cascade, namely factor _____
Factor VII
Elevated prothrombin time is more associated with what type of liver dz?
Acute
A decrease in albumin is generally associated with what type of liver disease?
Chronic
