digestion/GI (specific) Flashcards
What’s included in the GI tract?
the gastrointestinal tract and accessory organs such as the liver, biliary tract and pancreas
what does the GI tract cover?
mouth through to anus
large and small bowel obstruction
of the small intestines, occurs when lumen of the bowel becomes partially or completely blocked
two types of bowel obstruction
simple and strangulation
simple bowel obstruction
blockage without interfering with vascular supply
strangulation bowel obstruction
significant impairment of blood supply
causes of large bowel obstruction
magliancy, colonic diverticulum, volvulus, stricture, faecal impaction, hernias, intussusception
colonic diverticulum
small pouch or sac in the wall of the colon
volvulus
twisting, occurs when a loop of intestine twists around itself
hernias
weakening of the muscular walls
intussusception
walls stick together
perforation of bowel
free air under the diaphragm, hole in intestinal wall allowing gas to leak out
pneumoperitoneum
gas in the abdominal cavity
diverticula
small herniations in the intestinal wall
how is the diverticular disease be enhanced?
barium swallow
peritonitis
inflamed pouch ruptures, spilling intestinal contents into your abdominal cavity
pancreatitis
inflammation of the pancreas
auto-digestion
enzymes produced digest themself
epigastric
above the stomach
diagnosis of pancreatitis
- epigastric abdominal pain
- elevated lipase of amylase
- imaging
liver cirrhosis
scarring of the liver
stages of cirrhosis
stage 1- inflammation of the bile duct or liver
stage 2 - scarring of the liver due to inflammation
stage 3- cirrhosis
stage 4- liver failure
pruritus
itchy skin
oedema
swelling in the legs, feet or ankles
ascites
excess fluid in abdominal cavity
how does ascites impact radiographic exposure?
increase exposure factors
what’s the most common imaging modality in GI pathology?
fluoroscopy
jaundice
yellow skin and eyes
AAA
abdominal aortic aneurysm
Malena
blood turns black
heamatemesis
vomiting blood
IBD
inflammatory bowel disease
which two radiographs are usually performed for an acute abdomen?
supine abdomen, erect chest
two radiological features that differentiate a small bowel obstruction from a large bowl obstruction on an abdominal X-ray
- large diameter bowel loops on large bowel obstruction
- small bowel obstruction central, large bowel obstruction peripheral
identify three pathologies that may result in a perforated bowel
diverticulus, volvulus, appendicitis
identify 5 functions of liver
production of bile, filtration of blood, metabolism of drugs and food, storage of vitamins and mineral
identify the fluid the gallbladder releases
bile
how does bile support the digestion of fats
emulsifies fats. bile salts are able to bind to large undigested fat droplets, causing the droplets to break into smaller size droplets. offers up a large surface area for digestion of the fat droplets by pancreatic lipase
what does the small bowel consist of
duodenum, jejunum, ileum
what does the large bowel consist of
caecum, ascending, transverse, descending, sigmoid, rectum
mastication
reduces the size of the food, increases the surface area of food for digestion as it mixes food particles with saliva and digestive enzymes
what enzyme is in starch?
amylase
what enzyme is in fats?
lipase
function of HCL in stomach
kills microbes in food and converts pepsinogen into pepsin
function of pepsin in stomach
breaks down amino acids, optimal in a very acidic environment
intrinsic factor of the stomach
absorption of B12 and production of red blood cells
digestion in stomach
- combination of mechanical and chemical digestion
- triggered by stretching of stomach wall and change in pH (gastrin)
- mixing waves
- produces thin liquid called chyme
duodenum
first section of small intestine, presence of chyme in duodenum triggers next phase of digestion
function of gallbladder
storage and concentration of bile
function of bile
allows emulsification of fats
functions of liver
production of bile, carbohydrate, lipid and protein metabolism, processing of drugs or hormones, storage of vitamins and minerals, activation of vitamin D
three sections of the small bowel
duodenum, jejunum, ileum
function of jejunum
majority of food absorption of digested food
function of ileum
absorption of vitamin B12
structure of small intestine
- circular fold, villi and microvilli (increase surface area)
absorption of the small intestine occurs through which processes?
diffusion and active transport
what minerals does the small intestine absorb?
monosaccharides (glucose and galactose), amino acids, water & ions, lipids, vitamins
function of absorptive cells in the large intestine
absorbs water and ions
function of goblet cells in the large intestine
mucous lubricates the bowel wall
function of the large intestine
digestion, haustral churning, mass peristalsis
haustral churning
propels contents of colon, contraction of muscilaris causes churning of chyme which maximises absorption
function of rectum
mass peristalsis propels faeces from sigmoid colon into rectum
major hormones of digestion
gastrin, secretin, cholecystokinin
