GIT Flashcards
3 regions of the stomach
cardiac region - surrounds the cardiac orifice
body - midportion of the stomach
pyloric region - made up of the antrum and canal which terminates at the pylorus
Secretory cells of the gastric glands
chief cells - pepsinogen
parietal cells - HCl and intrinsic factor
mucous neck cells - mucous
enteroendocrine cells - secrete gastrin
Regulation of Gastric secretion
cephalic phase: central cortex, sight smell thought of food
Gastric phase: as food enters, stomach distension, reflexes, chemical and hormonal stimuli
Intestinal phase: low pH in stomach releases intestinal hormones (cholecystokinin and secretin)
Name the 4 accessory structures
salivary glands
liver
gall bladder
pancreas
Function of salivary glands
cleanses the mouth
moistens and dissolves food chemicals
aids in bolus formation
enzymes secretion that break down starch (amylase)
Function of Liver
produces bile
cleanses and detoxifies - anything that is ingested goes through the liver
COMposition of bile
bile salts
pigments
cholesterol
lecithin
Gallbladder function
stores extra bile
Pancreas function
secretes digestive enzymes
regulation of bile secretion both hormonally and chemically
disorders of motility
dysphagia gastroeosophageal reflux oesophageal diverticulum hiatal hernia pyloric obstruction
Dysphagia
difficulty swallowing
mechanical or functional obstruction of oesophagus
reduced muscle tone and peristaltic function, reduced food in stomach
Gastroesophageal Reflux
regurgitation of chyme from stomach into oesophagus
Can result in inflammation due to repeated exposure to acids and enzymes
symptoms of gastroeosophageal reflux
oedema
erosion
ulceration
Oesophageal diverticulum
outpouching of the oesophagus
food may be trapped
can lead to dysphagia and regurgitation
hiatal hernia
protrusion of upper part of stimach through hiatus at GI junction
sliding: congenital short oesophagus, trauma, weak diaphragmatic muscles
paraoesophageal: greater curvature of stomach herniates alongside oesophagus, creates a small balloon on its own
pyloric obstruction
narrowing or blockage of pylorus (between stomach and duodenum)
causes of pyloric obstruction
congenital defect
tumour
peptic ulcers
symptoms of pyloric obstruction
epigastric fullness
nausea
epigastric pain
Malabsorption syndromes (3)
pancreatic insufficiency
lactose enzyme deficiency
bile salt deficiency
Pancreatic insufficiency
insufficient enzyme production of CHO, ,fat and protein digestion
fat maldigestion leads to fat in stools
absence of HCO leads to reduced pH which prevents activation of pancreatic enzymes
lactose enzyme deficiency
inhibits lactose breakdown into mono-CHO which prevents lactose digestion and absorption
bile salt deficiency
bile salts necesary for fat digestion
causes fat malapsorption and steotorrhea
Gastritis
inflammation of gastric mucosa
acute: superficial erosions
chronic: thinning and degradation of stomach wall
types of gastritis
fundul: degeneration of fundus and stomach mucosa
antral: caused by helicobactor pylori bacteria
Peptic ulcers
acidic component that is causative in the disease progression
mucosal ulceration of stomach or duodenum
risk factors of peptic ulcers
smoking, alcoho, RA, cirrhosis, anti-inflammatory drugs, h.pylori, NSAIDS, aspirin
types of peptic ulcers
duodenal
gastric
stress
duodenal ulcers
increased gastrin which increases HCl production
symptoms: collicky, pain when stomach is empty
gastric ulcers
developed in antrum of stomach
gastric secretion normal or reduced
pain after eating
stress ulcers
develops after stress/trauma due to ischaemia
ischaemic: develops hours after heamorrhage
cushing: develops from reduced blood, increased HCl production
portal hypertension
increased BP in portal venous system caused by increased resistance to venous flow in portal vein, sinusoids and hepatic vein
blood finds alternative channels from portal vein to inferior vena cava thus bypassing the liver
causes of portal hypertension
pre-hepatic: blockage before blood enters the liver
intra-hepatic: blockage within the liver
post-hepatic: blockage outside the liver
consequences of portal hypertension
varices
ascites
hepatic encephalopathy
oesophageal varices
rupture of varices due to erosion by gastric acid and increased venous pressure leads to haemorrhage
ascites
accumulation of fluid in peritoneal cavity
fluid is trapped and cannot escape due to portal hypertension and reduced plasma proteins
ascites are caused by:
cirrhosis, congestive heart failure, pancreatitis
hepatic encephalopathy
complex neurologic syndomre characterised by impaired cerebral function, ECG changes, confusion, loss of consciousness coma and death
colitis
ulceration of colonic mucosa usually from colon to rectum
patho of colitis
primary lesion limited to mucosa, inflammation usually occurs in colon, mucosa becomes haemorrhagic - ulceration and necrosis follows
ulcerative colitis (UC)
chronic inflammatory disease causing ulceration, abscess formation, necrosis of colonic and rectal mucosa ONLY
symptoms of UC
cramping pain, bleeding, diarrheoa, dehydration and weight loss
crohn disease
affects large and small inestines but also oesophagus to rectum
ulceration involves all layers of lumen
symptoms of crohn disease
abdo tenderness and weight loss
diverticular disease
outpouching of colonic mucosa through muscle layers of colon wall leading to weak wall
divertiulosis:
diverticulitis:
presence of outpouching
inflammation of diverticula
appendicitis
inflammation of appendix
symptoms of appendicitis
nausea, pain, low grade fever
Intestinal obstruction
mechanical obstruction of bowel lumen
causes of intestinal obstruction
hernia
neoplasia
polyps
benign growth into lumen of large intestine
can be: neoplastic - adenamatous (proliferation of crypt cells)
non-neoplastic - hyperplastic (raised lesions on colonic mucosa)
haemorrhoids
dilation of venous plexus surrounding rectal and anal areas
dilated venous sacs protrude into rectal and anal canals: exposed, ulcerate, bleeding
haemorrhoids are due to
constipation
pregnancy
Cancer of oesophagus risk factors:
smoking alcohol malnutrition reflux sliding hiatal hernia
symptoms of oesophageal cancer
dysphagia
chest pain
cancer of the stomach
associated with high salt intake, food preservaties
symptoms of stomach caner
weight loss
upper abdo pain
colon and rectal cancer
pre-existing polyps highly associated with adenocarcinoma of colon
tumours of ascending colon usually large and bulky, tumours of descending and sigmoid colon develops as small button like masses
symptoms of colon and rectal caner
pain
bloody stools
change of bowel habits and movement
jaundice
yellow or greenish pigmentation of skin or sclera of eyes due to hyperbilirubinemia
can be obstructive - obstruction of bile canaliculi or ducts
haemolytic - destruction of RBC affects the livers abiilty to metabolise unconjugated bilirubin
hepatorenal syndrome
functional kidney failure caused by advanced liver disease with portal hypertension
renal failure caused by reduced blood flow to kidneys usually due to massive GI haemorrhage or liver failure
cirrhosis
irreversible inflammatory disease
disrupts liver structure and function
liver cancer
caused by metastic spread from primary site elsewere in the body
primary carcinoma: hepatocellular (in hepatocytes)
cholangiocellular (in bile ducts)
viral hepatitis
inflammation of liver with necrosis of hepatocytes
infection with hepatovirus
pancreatitis
inflammation of pancreas
causes of pancreatitis
alcoholism
peptic ulcers
chronic and acute pancreatitis
chronic: due to structural or functional impairment of pancreas. recurrent abdo pain and digestive disorder
acute: causes - gallstones, alcohol abuse. assoc with hyperlipidaemia, hyperparathyroidism, viral infection, abdo and surgical trauma, drugs
manifestation of pancreatitis
recurring episodes of epigastric and upper lieft quadrant pain anorexia nausea and vomiting constipation flatulence diabetes malabsorption syndrome
pancreatic cancer
adenocarcinoma arising in exocrine cells/ducts of the head, body and pancreatic tail
mortality 100%
causes of pancreatic caner
smoking diet diabetes chronic pancreatitis genetic
protective factorss against pancreatic cancer
dietary fiber
vitamin C
fresh fruits and veggies
no preservatives
manifestations of pancreatic cancer
pain - dull epigastric pain and back pain, relieved by sitting forward
jaundice
weight loss
nausea and vomiting
cholelithiasis
formation of gallstones
may retain in gallbladder or be ejected with bile into systic duct
cholecystitis
acute or chronic inflammation of gallbladder or cystic duct
occurs due to gall stones lodged in cystic duct
gallbladder becomes distended or inflammed with pain similar to gallstones
pigment stones
black stones - pts in a state of increased unconjugated bilirubin
brown stones - infection of biliary tree
risk factors of gallbladder dysfunction
Forty Fat Female Fertile Family Hx
Gallbladder cancer
primary carcinoma rare, mainly caused by metastasis
usually associated with cholelithiasis (stone formation)
