GIT 1 Flashcards
what is the gut ?
continuous tub from mouth to anus
which organs feed into the GIT?
liver
gall bladder
pancreas
what is the livers role in the GIT?
feeds into gall bladder
What is the role of the gall bladder?
secrets bile into duodenum
what is the role of the pancreas in GIT?
secrets pancreatic juices into the duodenum
where is the appendix situated ?
end of the ileum and beginning of colon just above the right hip bone
what is the role of the appendix
- blind ended tube
- evolutionary vestige - used to need when we were primitive (used to eat more vegetation)
- has bacteria that breaks down cellulose and gets nutrition from cellulose
- we don’t need it anymore
what happens when the appendix becomes blocked?
becomes necrotic
inflamed
pain and sepsis
needs removal
describe the lining of the mouth
stratified squamous epithelium
describe the lining of the stomach
mucus producing epithiulm and enzyme secreting
describe the lining of the small intestine
mucus
needs to absorbs nutrients so need high SA so have vili
describe the lining of the large intestine
less mucus
needs to absorbs nutrients so need high SA so have vili
describe the stomach
has mucous glands which secret acid too
what does the GIT tube have around it ?
layers of muscle which produce peristaltic waves which pushes food from one end to the other (to get water and nutrients removed)
what does the liver produce ?
bile salts - allows emulsification of fats to be more easily absorbed
where are bile salts stored ?
gall bladder
how is gall bladder contraction stimulated?
food leaving the stomach and entering the duodenum is mixed with bile via this contraction
why are our faeces brown?
bile is red and green
where does the pancreas release its secretions to ?
duodenum
what does the pancreas release?
an alkali solution which neutralises the acid from the stomach
releases pro enzymes
what are pro enzymes ?
inactive enzymes
why does the pancreas secrete pro enzymes instead of enzymes?
-there are a lot of proteases and lipases
- proteases break down protein and lipases break down fat
- if ur pancreases secreted these as active enzymes the pancreas would ingest itself
what is pancreatitis ?
auto digest pancreas
what else does the pancreas secrete?
insulin into the circulation in response to food in the GIT
describe the gut
- big blood supply to absorb nutrients from gut into portal venous system
- vili to maximise SA
describe the blood supply of the gut
- arterial blood flows from the aorta to the mesenteric arteries
what are the mesenteries ?
layers of tissue that connect the gut to the posterior abdominal wall
what would happen if the blood drained straight back into the vena cava?
we would have fat droplets, partially digested proteins, bacteria, toxins that would go straight into the circulation
where does the blood drain into from the gut?
into the portal venous system towards liver
what is the role of the liver once it receives nutrient rich blood?
liver hepatocytes filter and metabolise drugs, nuteinrts and vitamins before releasing them into systemic circulation
describe the parasympathetic stimulation of the gut
- promotes gut motility and gut secretion (increases capacity fro digestion with peristaltic waves and increases gut function)
describe the sympathetic stimulation of the gut
- reduces gut motility and secretion ( fight or flight, autonomic nervous system, increase BP, vasoconstriction, increase pulse rate and blood flow, decrease blood to gut so decreases its function)
list the signs and symptoms of GIT
what is a change in bowel habit?
no of times you go to the toilet for a no 2
what Is a normal bowel habit ?
- 3 times a day to once in 3 days
what do we mean by sustained change in bowel habit ?
any change longer than 2 weeks
why is learning about ones bowel habit useful?
it can be indicative of a gut condition
what are the causes of a painful bowel motion?
- severe constipation
- inflammation around lining of rectum or anus
- blood or mucus in bowel motions
- tenesmus - feeling of not having emptied bowel
why can the rectum feel?
- pressure or experience inflammation
- doesn’t have somatic nerves so it can’t detect exactly WHERE there is pain = can lead to tenesmus
what can give one tenesmus?
- tumour in rectum
- ulcerative colitis - inflammation can give one sensation of tenesmus
what does the stomach contain?
Low PH
enzymes
how is the stomach protected from low ph and enzymes to prevent it from being digested ?
the lining is protected by mucus
how does the lining produce mucus?
goblet cells and mucus glands
does the oesophagus secrete mucus?
NO
what causes GORD?
diet, stress and NSAIDs
what is the problem with GORD?
- contents of stomach can enter oesophagus to pharynx and damage it
what can protect the oesophagus ?
- lower oesophageal sphincter
- which passes through diaphragm at an angle
- if sphincter weakens it can cause reflux
list GORD symptoms
what can acid in the larynx and pharynx cause?
- thickening
- hoarse voice
- lump in throat (gp usually gives antacids to rule out reflux)
what are the risk factors for GORD ?
- Reduced tone of the lower oesophageal sphincter
- Increased intra-abdominal pressure (pregnancy, overweight and lying flat)
- Decreased stomach pH
- Increased stomach contents (alcohol, caffeine, fat in food)
what are the 3 factors for GORD?
- Lifestyle- stress, diet, overweight, alcohol and caffeine
- Mechanical
- Drugs- NSAIDs, serotonin inhibitors
how do we manage GORD
Address risk factors
Neutralise stomach contents (avoid risks and big fatty meals)
Gaviscon (Bicarbonate Physical barrier, Alginate)
Surgery to tighten lower oesphageal sphincter
what is an ulcer?
a pathological break in epithelial lining
what is peptic ulcer disease?
inflammation and break in epithelial lining of stomach and duodenum
what is the cause of peptic ulcer disease?
acid/ enzyme attack mucus caused by stress, steroids, NSAIDs, SSRIs, H.Pylori
pain in upper abdominal and epigastric
lis the symptoms of peptic ulcer disease
how do we manage PUD?
- upper GI endoscopy
- biopsy
- correct risk factors = increase stomach PH, PPI, eradicate H.pylori with clindamycin + metradiazole / amoxicillin
What is an inflammatory bowel disease?
A group of conditions characterised by inflammation of the intestine:
* Small intestine (ileum)
* Large intestine (colon)
* Rectum
* Anus
inflammation, ulcerations, variable thickness.
describe the symptoms of IBD?
Abdominal pain
change in bowel habit
blood loss
anaemia
oral signs
RAS
15-30 yrs peak
M=F
what are the extra- intestine effects of IBD?
fever, malaise
arthritis
skin lesions
eye lesions
what are the generalised features of IBD?
Abdominal pain
Weight loss
Change in bowel habit
Blood in poo
Fever
whats more common UC or Crohn’s?
UC
where does UC start at?
anus/ rectum and may affect more proximal large bowel
what does UC never affect?
ileum
what are the symptoms for UC?
rectal inflammation
bleeding
tenesmus
bloody diahorrea
smoking reduces the risk
where can crohns affect?
any part of small our large bowel
crohns aka?
regional ileitis
what are the main symptoms of crohns?
abdominal pain
diarrhoea
constipation
smoking can increase the risk
how much involvement is crohns ?
full thickness
can stick loops of bowels together
may lead to fistula formation
how would we diagnose IBD?
endoscopy
biopsy
CT scan
Tx of IBD
- Steroids - prednisolone
Sometimes be rectal but not systemically used - Methotrexate
- Azathioprine
- Aminosalicylates (Sulphasalazine and Mesalazine) related to asprin
- Biological response modifiers (Infliximab monoclonal antibody if no response to above)
what is coeliac disease?
- autoimmune Rxn to gluten
- wheat grain
- inflammation of small bowels
symptoms of coeliac?
abdominal pain
bloating
skin and mouth vesicles (extreme)
how are the vili affected ?
reduces height of vili
loss of SA
malabsorption
management of coeliac
avoid gluten
diagnosis of coelic
blood test, endoscopy, biopsy
Is IBS = IBD ?
NO, IBS isn’t an inflammatory disease but shares similar symptoms to IBD
important to exclude IBD and Bowel cancer
what is IBS ?
very common 20-50% ppl don’t tend to go GP
bloating, urgency or straining, abdominal pain
relieved by bowel movement
worse after eating
some have bladder urgency, lethargy, tired
risk factors of IBS?
Diet and lifestyle
what q’s can we ask to differentiate IBS to IBD or cancers
Do you have any blood or mucus in your poo?
Have you lost any weight?
Check for anaemia
Crohns disease summary
UC summary
coeliac disease summary
