HLTH digestive system review Flashcards
upper tract
mouth esophagus and stomach
lower tract
intestines
mesentery
is a double walled layer of peritoneum that supports the intestines; it attaches the jejunum and duodenum to the posterior abdominal wall
greater omentum
a layer of fatty peritoneum that hangs from the stomach like an apron over the anterior surface of the transverse colon and small intestine
lesser omentum
part of the peritoneum that suspends the stomach and duodenum from the liver
3 salivary glands
sublingual, submandibular, and parotid
what enzyme is found in saliva?
amylase which breaks down carbs and is secreted by the parotid gland
what are carbohydrates broken down to?
glycogen and disaccharides
what are triglycerides broken down into?
fatty acids and monoglyceride
what are proteins broken down to?
first peptides then amino acids
pepsin
is secreted by chief cells and breaks down proteins
what splits proteins into peptides?
Trypsin, chymotrypsin, and carboxypeptidase which are released by the pancreas
Intestinal peptidase
converts peptides into amino acids
what nerves are involved in swallowing?
V, IX, X, and XII
muscle in the esophagus
beginning in skeletal muscle but it is gradually replaced by smooth muscle
what do parietal cells secrete?
HCl and intrinsic factor
what do chief cells secrete?
pepsinogen which is later converted to pepsin by HCl
how is pepsin converted to its active form?
by HCl secreted by parietal cells
gastrin
released when food enters the stomach and stimulates parietal and chief cells to release their substances
glycogenesis
is converting glucose to glycogen
glycogenolysis
is breaking down glycogen to glucose when blood glucose levels drop
Gluconeogenesis
is the formation of glucose from molecules that are not carbohydrates
what hormones stimulate gluconeogenesis?
cortisol and epinephrine
what is the synthesis of cholesterol important for?
production of steroid hormones, sex hormones, and bile salts
what produces bile?
the hepatocytes
what is bile?
a mixture of water, bile salts, cholesterol, conjugated bilirubin, and electrolytes (including HCO3-)
function of HCO3- in bile?
it neutralizes the acidic gastric acid
what part of the small intestine is the major site of absorption?
the ileum
intestinal crypts
are found deep in the villi of the small intestine and give rise to new epithelial cells, as well as secrete an acidic fluid, enzymes, and hormones
enterokinase
activates pancreatic proenzymes and is produced by intestinal crypts
Peyer patches
large masses of lymphoid tissue in the large intestine which prevent the spread of infection to the small intestine
cephalic phase
occurs before eating when the smell or sight of food affects PNS stimulation
cholecystokinin
increases gastric secretions, stimulates pancreatic enzyme release, and stimulates release of bile; does not stimulate release HCO3 rich secretions
secretin
stimulates bile and pancreatic enzyme secretions that are rich in HCO3-
what part of the mesentery is responsible for controlling inflammation?
the greater omentum
how are proteins broken down throughout the GI tract?
pepsin will initiate splitting of proteins; trypsin or chymotrypsin will split proteins into peptides; then intestinal peptidase will convert peptides into amino acids
sucrase, maltase, and lactase
will convert disaccharides into monosaccharides
what materials are absorbed by hepatocytes?
minerals like iron and copper, folic acid, and vitamins A, B6, B12, D, and K
what organs are considered blood reservoirs?
the liver and spleen
what is bile pigment?
coagulated bilirubin
cranial nerves associated with saliva secretion
VII and IX
histamine and digestion
different than allergic reaction histamine as it is H2 receptors; causes increased secretion of HCl
signs preceding vomiting and nausea
tachycardia, pallor, diapedesis, and increased salivation
emesis
means vomiting
retching
may precede vomiting and is baby barf
hematemesis
blood in vomit which appears brown and coffee ground like
deeper brown vomit colour
may indicate lower intestinal obstruction
negative effects of bulimia
damage to oral cavity due to HCl, constipation or diarrhea, tear of the esophagus, and electrolyte imbalances
large volume diarrhea
is often associated with infections, lactose intolerance, or osmotic pressures causing water retention in the intestine
small volume diarrhea
is often associated with inflammatory bowel disease and often includes pus, blood, or mucus
when is steatorrhea common?
in those with celiac or cystic fibrosis
frank stool
is red visible blood on the surface of stool ususally resulting from lesions in the rectum or anal canal
occult stool
refers to small, hidden amounts of blood in stool; may indicate bleeding in the stomach or small intestine
melena stool
refers to dark stool from significant bleeding higher in the digestive tract, in which bacteria have acted on it, changing the colour
what can chronic constipation lead to?
diverticulitis and hemorrhoids
what ion is lost in vomiting?
chloride due to HCl being lost
what ion is lost in diarrhea?
potassium and HCO3-
why may severe vomiting cause metabolic acidosis?
HCO3- is lost from the small intestines, and ketones and lactic acid develop
burning sensation pain meaning
often indicates inflammation and ulceration in the upper digestive tract
cramping pain meaning
inflammation, distention, or stretching of the intestines
colicky or severe pain meaning
recurrent smooth muscle contraction due to inflammation or obstruction
somatic pain
is steady and well localized and can indicate inflammation of the parietal peritoneum due to pain receptors located here; can lead to abdominal guarding
why does referred pain occur?
when visceral and somatic nerves merge at a specific point at one spinal cord level
wasting syndrome
is chronic diarrhea associated with AIDS
in what disorder may pancreatic and bile secretions be interfered with?
cystic fibrosis due to mucus plugs
what conditions are stress reduction important for?
those with peptic ulcers or chronic inflammatory bowel disorders, in which exacerbations are stress related
how does stress affect digestion
the SNS is activated and vasoconstriction and ischemia of the mucosa can occur; high cortisol also inhibits regeneration of the mucosa
enterocolitis
refers to diarrheal diseases
signs of malnutrition in a child
chronic fatigue, reduced resistance to infection, and impaired healing
cleft lip
results when the maxillary processes does not fuse with the nasal elevations or failure of the upper lip to fuse; can be uni or bilateral; develops in the second or third month of gestation
cleft palate
is failure of the hard and the soft palates to fuse, creating an opening between the oral and nasal cavities; develops between 7-12 weeks of gestation
problems associated with cleft palate
feeding difficulties, speech problems, and potential aspiration
canker sores name
Aphthous ulcers
causes of aphthous ulcers
injury, toothpastes containing sodium lauryl sulfate, food sensitivities, allergic response, lack of vitamins, stress, hormones, H pylori, celiac, IBDs, and immune deficiency
aphthous ulcers appearance and location
small, shallow, painful lesions that are white surrounded by a red border and appear on the oral mucosa, buccal mucosa, floor of mouth, soft palate, and lateral borders of the tongue
oral candidiasis
is an oral fungal infection common in immunosuppressed individuals
oral candidiasis appearance
red, swollen, and curd like white areas
treatment for oral candidiasis
nystatin which is an antifungal
herpetic stomatitis
is caused by herpes simplex 1 virus and is transmitted by kissing or touching; virus stays dormant in the trigeminal nerve ganglion until activated by stress or infection; can be reactivated again in the future
herpetic stomatitis appearance
shallow, painful ulcer which releases a clear fluid then crusts over
herpetic stomatitis treatment
antivirals like acyclovir, valtrex, and famvir
organism causing syphilis
spirochete treponema pallidum
syphilis lesions
primary phase may form a painless ulcer in the oral cavity; secondary stage is red macules or papules similar to a skin rash
treatment of syphilis
penicillin
name for cavities
dental caries
common causative organisms for dental caries
streptococcus mutans or lactobacillus
how do dental caries develop?
bacteria act on sugar in ingested food to create large quantities of lactic acid that dissolve the tooth enamel
predisposing factors to developing dental caries
high amounts of sugar and carbonic acid (found in soda)
what is the periodontium?
the gingiva, the bone (alveolar), the ligaments, and the cementum
cementum
the outer covering of the root of the tooth
periodontitis
is the infection and damage to the periodontal ligament and bone, causing the loosening of teeth through microorganisms causing inflammation around the root of the tooth; usually caused by gram-negative bacteria
appearance of gingivitis
causes the gums to be red, soft, swollen, and bleed easy
causes of gingivitis
accumulated plaque due to poor oral hygeine or trauma brushing
calculus/ tartar
refers to calcified plaque
dark line of the gingiva meaning
can signify lead poisoning
necrotizing periodontal disease
infection of the oral cavity caused by opportunistic pathogens when tissues are damaged by smoking, stress, or poor nutrition
leukoplakia
a whitish plaque or epidermal thickening of the mucosa in the oral cavity and is related to smoking
common cancer of the oral cavity
squamous cell carcinoma
risks for oral cancer
smoking, leukoplakia, or alcohol
common sites for oral cancer
floor or the mouth and lateral borders of the tongue
spread of oral cancer
will first spread to lymph nodes then to the neck
Kaposi sarcoma
common in AIDs patients and appears as a brownish or purple macular lesion usually on the palate
sialadenitis
refers to inflammation of the salivary glands, infectious or non-infectious
what salivary gland is most often inflamed?
the parotid
mumps
is a viral infection that can lead to parotid gland bilateral inflammation
mucoepidermoid carcinoma
the most common tumor of the salivary glands and affects the parotid gland
what can dysphagia develop from?
a neurological disorder, muscle weakness, or an obstruction
neurologic causes of dysphagia
are those causing failure of the lower esophageal sphincter to open and can stroke, brain damage, and achalasia
congenital atresia
is a developmental disorder in which the lower and upper esophagus portions are separated
esophagus stenosis
is narrowing of this passageway that may be caused by developmental issues, fibrosis, radiation, inflammation, or ulceration
esophageal diverticula
are outpouchings of the esophageal wall that can be congenital or due to inflammation; food can accumulate here and cause obstruction and irritation
signs of esophageal diverticula
dysphagia, foul breath, chronic cough, and hoarseness
most common type of esophagus cancer
squamous cell carcinoma of the distal esophagus
causes of esophagus cancer
chronic irritation from smoking, alcohol abuse, or infections
hiatal hernia
part of the stomach protrudes through the hiatus of the diaphragm into the thoracic cavity
sliding hernia
is the more common type and occurs when a portion of the stomach and the gastroesophageal junction move above the diaphragm, often when supine and slides back when standing
rolling/ paraesophageal hernia
part of the fundus of the stomach moves through an enlarged or weakened hiatus in the diaphragm and blood vessels may become compressed which can lead to ulceration
complications of hiatus hernia
food may lodge in these areas, dysphagia, reflux, and obstruction
causes leading to hiatus hernia
shortened esophagus, weakness of the diaphragm, or increased abdominal pressure (e.g. pregnancy)
signs of a hiatus hernia
heartburn (brief burning followed by sour taste), frequent gas, dysphagia, discomfort lying down, and chest pain
Gastroesophageal reflux disease (GERD)
involves the periodic flow of gastric contents into the esophagus and is often seen with hiatus hernias
how does GERD occur
either due to a decrease in lower esophageal pressure or an increase in intra abdominal pressure
complications of GERD
inflammation, ulceration, and eventually fibrosis of the esophagus
acute gastritis
the gastric mucosa becomes inflamed and red, and ulcers or bleeding may develop
causes of acute gastritis
can be a result of infection, allergies, spicy foods, alcohol, aspirin, chemo/radiation, or toxic substances
signs of acute gastritis
nausea, vomiting, pain, cramps, ulcers, fever, and headache (no diarrhea)
gastroenteritis
is inflammation of the stomach and the intestines and is caused by infection or allergies to food or drugs
chronic gastritis
is characterized by atrophy of the mucosa of the stomach, with decreased secretions
complication of chronic gastritis
parietal cells don’t produce HCl or intrinsic factor, and vitamin B12 is not absorbed
who is chronic gastritis common in?
those with an H pylori infection, alcohol abuse, chronic peptic ulcers, the elders, and those with autoimmune diseases
risks for those with chronic gastritis
peptic ulcers and gastric carcinoma
most common place for peptic ulcers
the proximal duodenum; can also be found in the antrum of the stomach of esophagus
how do peptic ulcers appear?
as single, small, round cavities with smooth margins that penetrate the submucosa
indicators of peptic ulcers
iron-deficiency anemia or occult stool
common cause of gastric ulcers
impaired mucosal defences
common cause of duodenal ulcers
increased acidic secretions
H. pylori and peptic ulcers
the bacterium secretes cytotoxins and the enzymes protease, phospholipase, and urease which all damage the mucosa
causes of peptic ulcers
H. pylori, inadequate blood supply, stress, excessive glucocorticoids, aspirin, NSAIDs, alcohol, increased gastrin and pepsin secretions, and reduced gastric emptying
3 complications of peptic ulcers
hemorrhage, perforation, and obstruction
perforation with peptic ulcers
occurs when the ulcer erodes completely through the wall, releasing chyme into the peritoneal cavity
what blood group has peptic ulcers more commonly?
O
signs of gastric ulcers
epigastric burning after meals and at night, weight loss (sometimes gain), vomiting, nausea, and heartburn
stress ulcers
result from trauma (head injury or burns) or systemic causes (hemorrhage or sepsis); reduced blood supply causes damage to the mucosa, resulting in less secretions and regeneration
cushing ulcer
refers to a stress ulcer caused by head injury; often involve increased vagal nerve stimulation
curling ulcer
refers to a stress ulcer caused by burns
first indicator of stress ulcers
hemorrhage
where does gastric cancer occur?
in the mucus glands mainly in the antrum or pyloric area
most common type of gastric cancer
adenocarcinoma
early vs advanced gastric cancer
early is confined to the mucosa and submucosa but advanced effects the muscularis
where does gastric cancer often spread to?
the liver and ovaries
causes of gastric cancer
H pylori infection, food preservatives, smoked foods, type A blood, and diet
signs of gastric cancer
anorexia, feelings of indigestion, weight loss, and fatigue
dumping syndrome
occurs when loss of the pyloric sphincter causes dumping of chyme into the duodenum and often follows gastrectomy
signs of dumping syndrome
the osmotic forces of chyme cause hypovolemia and hypoglycemia, causing dizziness, sweating, rapid pulse, nausea, and vomiting
treatment for dumping syndrome
eating small, frequent meals high in protein and low in simple carbs, as well as having water between meals not with meals
pyloric stenosis
is narrowing of the pyloric sphincter due to fibrous scar tissue or hypertrophy of the smooth muscle; can be congenital or acquired
acquired pyloric stenosis
is due to fibrous scar tissue and causes fullness and vomiting
congenital pyloric stenosis
is due to hypertrophy of the smooth muscle and leads to hunger, vomiting, dehydration, and small infrequent stools
cholelithaias
is formation of gallstones
cholecystitis
is inflammation of the gallbladder and cystic duct
cholangitis
is inflammation of the bile ducts
choledocholithiasis
is obstruction by gallstones of the biliary duct
gallstones
consist of calcium, cholesterol, and bile pigment (coagulated bilirubin)
cholesterol stones
appear white or crystal
bilirubin stones
appear black
gallstones causes
usually due to a deficiency is bile salts or an increase in cholesterol; also can be due to inflammation in the bile or cystic ducts, oral contraceptives, or giving birth to multiple children
common infective organism causing gallstones
E coli
biliary colic
refers to severe, colickly pain and spasms attempting to pass the gallstone
signs of gallstones
usually are asymptomatic but may cause biliary colic, pain that radiates to the back and right shoulder, nausea, and sometimes jaundice
who are bile gallstones common in?
those with hemolytic anemia, alcoholic cirrhosis, or biliary tract infection
icterus
another word for jaundice
jaundice
refers to the yellow colour of the skin due to high amounts of bilirubin in the blood which results from RBC breakdown or the breakdown of hemoglobin
prehepatic jaundice
often follows hemolytic anemias or transfusion reactions; liver function is normal but the large amounts of bilirubin cannot be processed
intrahepatic jaundice
is common in those with liver disease like hepatitis or cirrhosis; it is associated with impaired uptake of bilirubin and decreased coagulation of bilirubin by hepatocytes
posthepatic jaundice
is caused by obstruction of bile flow and backup of bile in the blood; can be due to tumors, inflammation of the liver, or atresia of bile ducts
what jaundices have unconjugated bilirubin what have conjugated?
pre has unconjugated, intra has both, and post has conjugated
chronic liver inflammation
is inflammation for > 6 months and is associated with hep B, C, and D
what hepatitis have a carrier state?
B, C, and D
hep A
is transmitted by the oral-fecal route, often by contaminated water or shellfish; is acute and self-limiting
hep B
is associated with HIV and transmitted by body or body secretions; has a long incubation period and can be asymptomatic
hep C
is most common virus transmitted with blood transfusions and may increase the risk for developing hepatocellular carcinoma
hep D
is transmitted by blood and requires HBV to replicate and produce an active infection; it also increases the severity of HBV
hep E
is transmitted by oral-fecal route and causing a high mortality rate in pregnant women
preicteric
prodromal period of hepatitis infections and is characterized by fatigue, anorexia, nausea and general muscle aching; aminotransferase levels are elevated
icteric
is second stage in hepatitis infection and includes signs of jaundice, light coloured stool, dark urine, itching skin, impaired blood clotting, and hepatomegaly; longer in hep B
posticteric
is last stage of hepatitis and is recovery with marked reduction in signs
hepatotoxins
chemicals or toxins that cause inflammation and necrosis in the liver, causing an immune response or direct effects of toxins
examples of hepatotoxins
acetaminophen, tetracycline, and halothane
cholestasis
refers to obstructed flow of bile and can occur as a result of hepatotoxins
cirrhosis
refers to progressive destruction of liver tissue, leading to liver failure; liver undergoes fibrosis and lobular organisation is lost; it is initially larger then shrinks; 4 types
biliary cirrhosis
is associated with immune disorders causing obstruction of bile flow like cystic fibrosis or stones
postnecrotic cirrhosis
is associated with chronic hepatitis or long term exposure to toxins
metabolic cirrhosis
is caused by storage disorders like hemochromatosis
acetaldehyde
is a metabolite of alcohol which is toxic to the liver cells
how does alcoholic liver fibrosis develop?
first the liver becomes fatty, then inflammation, necrosis, and fibrous tissue develop; this fibrous tissue eventually replaces normal tissue
hepatic encephalopathy
refers to the nervous system being affected due to high levels ammonia and toxins in the blood
ammonia
protein of protiein metabolism that is converted to urea in the liver
3 factors causing ascites in cirrhosis
increased hepatic hypertension, increased inactivation of aldosterone, and decreased plasma proteins
most common liver cancer
hepatocellular carcinoma which develops in cirrhotic livers
liver cancer signs
general cancer signs, splenomegaly, portal hypertension, and paraneoplastic signs due to the tumor secreting substances similar to erythropoietin, insulin, and estrogen
pancreatitis
is inflammation of the pancreas resulting from autodigestion of tissues to to pancreatic proenzymes being activated in the pancreas; can be acute or chronic
what is the first enzyme to be activated in pancreatitis?
trypsin
what does chemical peritonitis occur in pancreatitis?
the inflammatory response that causes increased vascular permeability and vasodilation
complications of pancreatitis
chemical peritonitis which may develop into bacterial peritonitis, hypovolemia, septicemia, adult respiratory distress syndrome, and acute renal failure
causes of pancreatitis
gallstones and alcohol abuse
primary symptom of pancreatitis
severe abdominal pain that radiates to the back
major risk factor for pancreatic cancer
smoking
early signs of pancreatic cancer
jaundice and weight loss
most common type of pancreatic cancer
adenocarcinoma
what type of jaundice has light coloured stool?
posthepatic
what hepatitis has cell-mediated responses to the virus?
B
what ion binds to fatty acids?
calcium; thus hypocalcemia is common in pancreatitis
celiac disease
is a deficit in the enzyme gliadin which breaks down gluten which cause the villi of the intestine to atrophy, leading to malabsorption and malnutrition
signs of celiac disease
steatorrhea, muscle wasting, failure to gain weight, and irritability
risks associated with celiac disease
an increased risk for intestinal lymphoma
what areas of the GI tract does crohn’s disease effect
the ileum and sometimes the ascending colon and affects all layers of the intestine
skip lesions
present in Crohn’s disease and are affected segments separated by areas of normal tissue
signs of crohn’s disease
diarrhea, abdominal cramping, melena bleeding, pain and tenderness in URQ, and malnutrition signs
how does the intestine appear in crohn’s
narrow, granulomas develop, skin lesions, adhesions between loops of intestine, fistulas may form between adhesions, and abscesses develop in the intestinal wall
what areas of the GI tract does ulcerative colitis affect?
the rectum and then progresses up the colon; only the mucosa is affected
how does the intestine appear in ulcerative colitis?
red, friable, with ulcers, granulation tissue forms, and bridges of intact mucosa form over the ulcers
toxic megacolon
occurs in acute episodes of ulcerative colitis when the transverse colon is totally obstructed
risk with ulcerative colitis
colorectal cancer
signs of ulcerative colitis
diarrhea with blood and mucus, tenesmus (spasms of the rectum), and rectal bleeding
diet for chronic irritable bowel disease
high in protein and nutrients but low in fat
causes of IBS
hypersensitivity reaction, the effect of serotonin on the GI tract, activated mast cells and T cells, overgrowth of flora, food allergies or intolerances, and emotional stress
how does appendicitis develop?
fecalith is obstructed in the appendix, followed by fluid and microorganisms accumulating here; inflammation and purulent exudate form, and necrosis and ischemia occur; peritonitis may develop and rupture of the appendix
diverticulum
is an outpouching or herniation of the mucosa through the muscularis wall, most often in the sigmoid colon
diverticulosis
is asymptomatic but refers to the presence of multiple diverticulum
diverticulitis
refers to inflammation of the diverticulum
where do diverticulum form?
at gaps between longitudinal muscle that coincide with openings in the circular muscle
what may lead to the formation of diverticula
low-residue diets, irregular bowel habits, aging, and muscle hypertrophy in the colon
what do most colorectal cancers develop from?
adenomatous polyps which is a mass that protrudes into the lumen
where are projecting polypoid masses common?
the right colon
where are napkin ring growths common?
the left colon
where does colorectal cancer spread to?
the liver
CEA
carcinoembryonic antigen that is an indicator of colon cancer
ascending colon cancer signs
occult stool and anemia
transverse colon cancer signs
semi-solid feces, anemia, and occult stool
descending colon cancer signs
solid stool, constipation, red or dark blood in stool
rectum cancer signs
incomplete emptying, ribbon stool, and red blood on the surface of stool
paralytic ileus
refers to obstructions of the intestines due to neurological impairment
volvulus
means twisting of the intestine
what can intestinal obstruction lead to?
peritonitis
hirschsprung disease
is a condition in which parasympathetic innervation is missing from a section of the intestine, impairing motility and leading to constipation
Borborygmi
refers to audible rumbling sounds
chemicals irritants that may cause peritonitis
bile, chyme, or foreign objects
what occurs initially with peritonitis?
a thick, sticky exudate is produced to seal the area
why does rigid, boardlike abdomen occur with peritonitis?
as a reflex causing spasm of the abdominal muscles
signs of peritonitis
generalized abdominal pain, vomiting, signs of dehydration and hypovolemia, decreased skin tugor, dry buccal mucosa, pallor, low BP, tachycardia, decreased bowel signs, and fever
intussusceptions
refers to the telescoping of one section of bowel inside another
