GI Phys Flashcards
Mouth: CN ass. with taste (3)
Taste buds (CN VII, CN IX) Salty, sour, bitter, sweet, and umami (savory)
Olfactory nerves (CN I)
Salivary Glands (3)
Submandibular
Sublingual
Parotid
Saliva
what it is made up of (6)
what it is used for
Water with mucus, sodium, bicarbonate (so acid doesn’t kill amylase), chloride, potassium, and amylase (carbohydrate digestion)
needed to form a bolus
smooth muscle wave
Peristalsis
Upper esophageal sphincter (UES):
aka
function
disfunction
must relax to allow food to pass
Upper esophageal Stenosis leading to aspiration
Lower esophageal sphincter (LES)
aka
function
disfunction
cardiac sphincter
allows food into stomach
Sphincter insufficiency leading to GERD
Lower esophageal Stenosis leading to emesis
Stomach: 3 Muscle layers allow for churning
Longitudinal
Circular
Oblique
secretes digestive juices
pepsinogen
partially digested food
chyme
Stomach: Cardiac sphincter Pyloric sphincter Pylorus duodenum Fundus
Cardiac sphincter (upper)
Pyloric sphincter (lower)
Pylorus: the opening from the stomach into the duodenum (small intestine).
Fundus: the upper part of the stomach, which forms a bulge higher than the opening of the esophagus
Body
HCl Acid:
Enzymes:
Hormones
Intrinsic factor
HCl Acid: activates pepsinogen, kills pathogens,
Enzymes: pepsinogen converted into pepsin (by CHl Acid)
Hormones: Intrinsic factor- B12 absorption, pernicious anemia
Parietal cells
Chief cells
G cells
Ghrelin
Parietal cells: Hydrochloric acid and intrinsic factor
Stimulates chief cells
Chief cells: secrete Pepsinogen
G cells:secrete Gastrin: increase HCl secretion
Ghrelin: works on brain to stimulate hunger
Sm intestine
Three segments:
Duodenum
Jejunum
Ileum
Ileocecal valve
Peritoneum
Sm intestine
Villi:
Microvilli
Lacteal
Villi: Finger like extensions on the inner wall increasing surface area
Microvilli
Brush border: increase surface even MORE (for absorption)
Lacteal: lymph duct, absorb digestive fat
Intestinal Absorption (8)
Carbohydrates Proteins Fats Water Electrolytes Vitamins Minerals
Large Intestine: entrance
Cecum
Intestinal Bacteria
function
location
increased bacterial location
Bile acid secretion, motility, and antibody production keeps bacteria low in duodenum
Low concentration of aerobes in the jejunum
Bacterial numbers increase distal to the ileocecal valve
95% anaerobic strains
Liver
function
Liver lobules
Kupffer cells
Mainly filters deoxygenated blood
Drains into hepatic portal system
Helps to clean and detoxify, metabolize, stores stuff from GI.
Common bile duct:
Liver lobules
Hepatocytes
Sinusoids (Specialized Capillaries)
Kupffer cells: involved in the breakdown of red blood cells.
Liver: Bile
what it is
Bilirubin
Formation
Bile is an alkaline, bitter-tasting yellowish green fluid that contains bile salts (come from cholesterol), bilirubin, electrolytes, and water
Bilirubin is a by-product of the destruction of aged red blood cells and gives bile a greenish black color and produces the yellow tinge of jaundice
Functions of Liver (7)
1) Blood storage
2) Bacterial and foreign particle removal
3) Synthesizes plasma proteins (albumin, drive oncotic pressure)/clotting factors (fibrinogen etc.)
4) Produces bile
5) Metabolizes fats, proteins, and carbohydrates (stored as glycogen)
6) Detoxification of metabolic products/wastes (ethanol alcohol, ammonia- waste product from the break down of proteins, liver converts into urea which is sent to kidneys)
7) Storage of minerals and vitamins
The gallbladder
what it is
function
volume of bile
a saclike organ that lies on the inferior surface of the liver
The function of the gallbladder is to store and concentrate bile between meals
The gallbladder holds about 90 mL of bile
The exocrine pancreas
what it is composed of
composed of acini and networks of ducts that secrete enzymes and alkaline fluids (bicarb to combat gastric acid) to assist in digestion
Diff. from endocrine pancreas
Pancreas Secretions (6)
Bicarbonate
Zymogens: activated from inflammatory response
Trypsinogen, chymotrypsinogen, procarboxypeptidase
Pancreatic amylase
Pancreatic lipase
Nucleases
Abdominal pain
assessment
Abdominal pain is a symptom of a number of gastrointestinal disorders
assessed by which quadrant
do not have large A nociceptors, referred pain is common
Osmotic diarrhea:
(pull and attraction of water into GI) major imbalance in osmotic balance causing water to not be pulled into the blood stream and instead is pulled in the intestines (eg: high Na+ or protein intake)
Secretory diarrhea:
Mucous is being brought into the intestines to fight an immune response and eliminate unwanted things
Motility diarrhea:
over activation of peristalsis, over activation (IBS), use of caffeine, stress
Gastrointestinal bleeding
Upper gastrointestinal bleeding:
Lower gastrointestinal bleeding:
Upper gastrointestinal bleeding:
Esophagus, stomach, or duodenum
Lower gastrointestinal bleeding:
Jejunum, ileum, colon, or rectum
Hematemesis:
Hematochezia:
Melena:
Hematemesis: coffee grounds (digested by gastric acid), upper GI bleed (esophagus or duodenum)
Hematochezia: vivid red blood in stool, fast active bleed, rectum or sigmoid bleed, hemorrhoids
Melena: black tary stool (the blood is being digested), GI bleed (above sigmoid colon and bellow the stomach)
Dysphagia
is difficulty swallowing
issue with motility
upper esophageal stenosis
impairs peristalsis movement thought the esophagus
Achalasia
Denervation of smooth muscle in the esophagus and lower esophageal sphincter
specifically from an immune response
Normal functioning lower esophageal sphincter
what it does
what occurse with malfunction
If GER causes inflammation of the esophagus, it is called
what can contribute to GERD
maintains high pressure to prevent chyme reflux
GERD (Gastroesophageal reflux)
reflux esophagitis
Conditions that increase abdominal pressure or delay gastric emptying
Hiatal hernia
Hiatal:
Sliding:
Paraesophageal: fundus
where the vena cava, aorta and esophagus pass from the thorax in to the abd
Protrusion of upper portion of stomach through diaphragmatic hiatus into thorax
the stomach slides up though (more common)
the fundus also slides though
Inguinal Hernia
occurs when tissue, such as part of the intestine, protrudes through the inguinal canal
More common in males b/c testie sometime has to be passed though
Pyloric obstruction
Blocking or narrowing (stenosis) of the opening between the stomach and the duodenum
leads to n/v after eating meals
Dumping syndrome
Pyloric insufficiency
clinical complication from what
Rapid emptying of chyme from a surgically created residual stomach into the small intestine
Pyloric insufficiency: food is allowed to pass too quicky (before it is fully digested)
Dumping syndrome is a clinical complication of partial gastrectomy or pyloroplasty surgery
Ileus
An ileus is an obstruction of the intestines from folding, pinching, or lack of peristalsis
Peptic ulcer
A break or ulceration (erosion) in the protective mucosal lining of the lower esophagus, stomach, or duodenum (most common)
Peptic ulcer: Duodenal ulcers
what it is
cause
Most common of the peptic ulcers
Helicobacter pylori infection (most common)
Toxins and enzymes that promote inflammation and ulceration
primarily comes from ingestion of fecal matter
Use of NSAIDs
Hypersecretion of stomach acid and pepsin
Acid production by cigarette smoking
Peptic ulcer: Gastric ulcers
what it is
cause
Tend to develop in the antral region (pylorus) of the stomach
Most common causes are use/overuse of NSAIDs, H. pylori, gastritis, alcohol abuse
Peptic ulcer: Esophageal ulcers
what it is
cause
Most commonly caused by GERD
Others include: use of NSAID’s, smoking, effects of forced vomiting in Bulimia cases
Stress ulcers
what it is
cause
a peptic ulcer
related to severe illness, neural injury, or systemic stress/ trauma, emotional stress, intubation
Pancreatic insufficiency
what it is
cause
Insufficient pancreatic enzyme production
Lipase, amylase, trypsin/chymotrypsin
Causes include pancreatitis, pancreatic carcinoma, pancreatic resection, and cystic fibrosis
Fat maldigestion is the larger problem, so the patient will exhibit fatty stools (steatorrhea) and weight loss
steatorrhea
fatty stools
Lactase deficiency
what it is
cause
Inability to break down lactose (sugar in dairy) into monosaccharides and therefore prevent lactose digestion and monosaccharide absorption
Fermentation of lactose by bacteria causes gas (cramping pain, flatulence, etc.) and osmotic diarrhea
NOT the same as being allergic to lactose
Bile salt deficiency
what it is
cause
Conjugated bile salts are synthesized from cholesterol in the liver needed to emulsify and absorb fats.
Can result from liver disease and bile obstructions
Poor intestinal absorption of lipids causes fatty stools, diarrhea, and loss of fat-soluble vitamins (A, D, E, K)
Fat-soluble vitamin deficiencies: Vitamin A Vitamin D Vitamin K Vitamin E
Vitamin A
Night blindness
Vitamin D
Decreased calcium absorption, bone pain, osteoporosis, fractures
Vitamin K
Prolonged prothrombin time, purpura, and petechiae
make clotting factors (more prone to bruising)
Vitamin E
based DNA and cell functions
Gastritis:
what it is
cause (acute/ chronic)
inflammation of stomach wall
Inflammatory disorder of the gastric mucosa
Acute gastritis: stress
Chronic gastritis: autoimmune, chronic alcohol use
Ulcerative Colitis
what it is
cause
s/s
Chronic inflammatory disease that causes ulceration of the colonic mucosa
Typically occures in the Sigmoid colon and rectum
Idioathic
May lead to increased risk of colon cancer
s/s Hematochezia
Crohn’s Disease
what it is
cause
s/s
inflammatory disorder that affects any part of the digestive tract, from mouth to anus (main diff. from UC)
Idiopathic
Difficult to differentiate from ulcerative colitis
Similar risk factors and theories of causation
s/s ‘skip lesions’ and ‘cobblestone effect’
Diverticular Disease of the Colon:
Diverticula
Diverticulosis
Diverticulitis
Diverticula
Herniations of mucosa through the muscle layers of the colon wall, especially the sigmoid colon
can be due to a lack of fiber
Diverticulosis
Asymptomatic diverticular disease, weakened wall
Diverticulitis
The inflammatory stage of diverticulosis
more abd pain
Appendicitis
what it is
cause
s/s
Inflammation of the vermiform appendix likely from infection
Possible causes are obstruction, ischemia, increased intraluminal pressure, infection, ulceration, etc.
RLQ pain w/ rebound tenderness
Irritable Bowel Syndrome (IBS)
cause
who is effected
Idiopathic GI disorder with no specific structural or biochemical alterations as a cause of disease. NOT due to inflammation!
20% world population More common in women Youth and middle age Associated with anxiety and depression (serotonin in the gut) Gut flora (may try probiotic treatment)
Celiac Disease
what it is
cause
s/s
T-cell immune reaction damages intestinal epithelial cells and leads to inflammation
Gluten is the protein component in wheat, rye, barley, malt
The disease appears to be caused by dietary, genetic, and immunologic factors (hypersensitivity)
Causes atrophying and flattening of villi, malabsorption from changes to intestinal mucosa, water and electrolyte osmotic changes leads to diarrhea
Anorexia nervosa
what it is
s/s
A person has poor body image disorder and refuses to eat
Anorexic patients can lose 25% to 30% of their ideal body weight as a result of fat and muscle depletion
Can lead to starvation-induced cardiac failure
Bulimia nervosa
what it is
s/s
Body weight remains near normal but with aspirations for weight loss
Recurrent episodes of binge eating (2 episodes per week for at least 3 months)
Self-induced vomiting
Fasting to oppose the effect of binge eating, or excessive exercise
Continual vomiting of acidic chyme cause pitted teeth, pharyngeal and esophageal inflammation, and tracheoesophageal fistulas, overuse of laxative can cause rectal bleeding
tracheoesophageal fistulas
an abnormal connection in one or more places between the esophagus and the trachea.
Normally, they are two separate tubes.
Short-term starvation:
Glycogenolysis
Gluconeogenesis
Long-term starvation:
Marasmus
Kwashiorkor
Cachexia
Glycogenolysis: the breakdown of glycogen (stored energy) into glucose (used to produce energy).
Gluconeogenesis: When glycogen stores are depleted and glucose is required by the body, the liver initiates the production of glucose from amino acids, lactate, and glycerol
Marasmus: severe undernourishment causing an infant’s or child’s weight to be significantly low for their age
Kwashiorkor: characterized by edema and an enlarged liver with fatty infiltrates. It is caused by sufficient calorie intake, but with insufficient protein consumption
Cachexia: wasting
Portal hypertension
Intrahepatic
Posthepatic
is caused by abnormally high blood pressure that caused by obstruction of blood flow in the portal venous system or vena cava.
Intrahepatic: intra=within +hepatic=liver: result from vascular remodeling with shunts, thrombosis, inflammation, or fibrosis, cirrhosis of the liver, viral hepatitis, or parasitic infection.
Posthepatic: post= after: occurs from hepatic vein thrombosis or cardiac disorders that impair the pumping ability of the right side of the heart. This causes blood to collect and increases pressure in the veins of the portal system. The most common cause of portal hypertension is fibrosis and obstruction caused by cirrhosis of the liver.
Portal hypertension:
Consequences
Varices
Splenomegaly:
Ascites:
Hepatic encephalopathy:
Varices
Back up of venous blood that can lead to vein rupture and bleeding in the GI tract (Lower esophagus, stomach, rectum)
Splenomegaly: spleen becomes enlarged
Ascites: lack of albumin
Hepatic (liver) encephalopathy (disease of the brain): the liver is causing disfunction in the brain due to a build up ammonia
Hepatic encephalopathy
The loss of brain function when a damaged liver doesn’t remove toxins from the blood.
Develops rapidly during fulminant hepatitis or slowly during chronic liver disease
Hepatic encephalopathy generally occurs in people with chronic liver disease, such as cirrhosis or hepatitis. Triggers include infection and dehydration.
Neurons are vulnerable to neurotoxins absorbed from the GI tract that circulate to the brain because of liver dysfunction
Jaundice
Obstructive jaundice:
-Posthepatic obstruction
-Intrahepatic obstruction
Hemolytic jaundice:
-Prehepatic jaundice
Lack of bilirubin metabolism in liver leading to yellowing
- Posthepatic: post= after: occurs from hepatic vein thrombosis (Gallstone obstruction ) or cardiac disorders that impair the pumping ability of the right side of the heart. This causes blood to collect and increases pressure in the veins of the portal system.
- Intrahepatic: intra=within +hepatic=liver: result from cirrhosis of the liver, viral hepatitis.
-Hemolytic jaundice:
Prehepatic jaundice: Excessive bilirubin in the body. Spleen, major bodily trauma
Viral Hepatitis
Hepatitis A, B, C, D, E, and G
Systemic viral disease of acute or chronic inflammation that primarily affects the liver
Hepatitis A: transmitted by the fecal-oral route usually in Crowded, unsanitary conditions; Food and water contamination. Vaccine.
Hepatitis B: Transmitted by infected blood, body fluids, or contaminated needles. Maternal transmission can occur if the mother is infected during the third trimester
Can cause chronic Hepatitis. vaccine
Hepatitis C: Transmitted by blood. Responsible for most cases of post-transfusion hepatitis (baby boomers). Also implicated in infections related to IV drug use.
50% to 80% of hepatitis C cases result in chronic hepatitis. Leads to chronic liver disfunctio. No vaccine yet (getting close!)
Hepatitis D: Depends on hepatitis B for replication
Hepatitis E: Fecal-oral transmission
Developing countries
Hepatitis G: Parentally and sexually transmitted
Recently discovered
Cirrhosis
what it is
Irreversible inflammatory disease that disrupts liver function and even structure
Slow development to chronic disease
Decreased hepatic function caused by nodular and fibrotic tissue synthesis (hard and scared)
Biliary channels become obstructed and cause portal hypertension
Blood can be shunted away from the liver, and a hypoxic necrosis develops
Cirrhosis:
Alcoholic
Biliary
Fatty Liver Disease
Alcoholic
Oxidation of alcohol damages hepatocytes
most common
Biliary (bile canaliculi)
Cirrhosis begins in the bile canaliculi and ducts
Fatty Liver Disease
Fat build up causes fibrosis and scarring
Non-alcoholic Steatohepatitis (NASH)
cholecystitis (kow·luh·si·stai·tuhs)
inflammation of the Gallbladder. the most common cause of gallbladder problems
Cholelithiasis
what it is
cause
Gallstones form in the bile as a result of the aggregation of cholesterol crystals (cholesterol stones) or precipitates of unconjugated bilirubin (pigmented stones). Gallstones that fill the gallbladder or obstruct the cystic or common bile duct cause abdominal pain and jaundice.
Pancreatitis
what it is
cause
inflammation of the pancreas
Caused by an injury or damage to pancreatic cells and ducts, causing a leakage of pancreatic enzymes into the pancreatic tissue
Activated zymogens cause autodigestion of pancreatic tissue and leak into the bloodstream to cause injury to blood vessels and other organs
Chronic pancreatitis
Related to chronic alcohol abuse
Intrinsic Factor
a substance secreted by the stomach which enables the body to absorb vitamin B12. It is a glycoprotein.
