101 Diarrhoea Flashcards
At which level is the bifurcation of the abdominal aorta?
L IV

At which level does the common iliac veins drain into the vena cava?
LV
At which level does the IMA branch off the abdo aorta?
L III
Between which 2 structures is the epiploic foramen found?
Between the greater and the lesser sac
Why is there initally generalised abdominal pain followed by more acute localised pain to the right iliac fossa in appendicitis?
Visceral peritoneum= sensitive to stretch –> generalised pain referred from here.
More localised pain from the inflammed appendix irritating the parietal peritoneum
Which ligament is found in the dj junction?
What is its purpous?
Ligament of Treitz - skeletal muscle which contracts to widen the angle of the dj felxure and allow m’ment of intestinal contents
Which nerves supply the lateral 2/3rds of the diaphragm?
T VII to T XII
Where does the root of the mesentary extend from?
L side of L2 –> R SI joint
How do you differentiate the mesentary of the jejenum from the ileum?
Vasa recta –> ileum =shorter
Arterial arcades –> ileum more numerous
Name the 6 possible positions of the appendix

Which organ does the transverse mesocolon attach to superiorly?
Pancreas
Which ligament suspends the splenic flexure?
Phrenicocolic ligament
In females, what are the anatomical relations to the sigmoid colon?
Posterior surface of the uterus ad upper part of the vagina
The pull of which muscle makes the anorectal angle?
Puborectalis portion of levator ani
Name the broad longitudinal bands which run along the large colon?
Taenia coli
Name the circular folds of the small colon
Plicae circulares
Where in the GIT has thick stratified squamous non keratinising epithelium?
Oral cavity
Where is Meissner’s complex found?
In the submucosa
Which ANS plexus is found between the layers of circular and longitudinal muscle?
Auerbach
Describe the muscularis externa in each third of the oesophagus
Top = striated muscle
Middle = mixture of striated and smooth
Bottom = SM
Name the 4 layers of GIT
Mucosa,
Submucosa,
Muscularis propria (inner circular, outer longitudinal)
Serosa
What’s the difference between the epithelium of the oesophagus at the cardio-oesophageal junction?
Stratified squamous epithelium proximal to the junction then changes to simple columnar –> goblet cells here secreting mucous to counteract the damage gastric acid inflicts on the epithelium
Where is the function of parietal cells and where are they found?
Secrete HCl and peptide for B12 antibodies (stimulated by gastrin and ACh) - found in the mucosa of the stomach (mainly the body) within the gastic pits
Which cells secrete rennin, pepsinogen and gastric lipase - where are they found?
Chief cells - in the base of the gastric glands
What do the enterochromafifn-like cells found and what do they secrete?
In the neck of the gastric pits - secrete histamine. Stimulated by gastrin which is released by G cells (stimulated by vagus)
Where in the stomach will no chief cells be present?
Pylorus
What are Brunners glands?
Tubuloacinar glands which penetrate the muscularis mucosa of the duodenum. They secrete mucous to alkanalise the acidic chyme from the stomach.
What is the pH of the duodenum?
pH 9
What is the role of cholecystokinin and secretin in the duodenum?
To stimulate the pancreas to secrete digestive enzymes and to stimulate contraction of the gallbladder
Name the 3 types of cells in the crypts of Lieberkhun
- Paneth cells - contain granules of antimicrobial compounds
- Endocrine
- Stem cells
How much fluid is taken into the GIT through diet?
1500ml
How much fluid is secreted into the lumen of the jejenum?
7000ml
How much fluid is absorbed by the colon?
1400ml
How much fluid is needed to form a stool in the rectum?
100ml
How is H2O moved across the intestinal mucosa?
It moves passively through the work of electrochemical gradients provided by active transport of electrolytes
Where is vitamin B12 absorbed? What is the consequence of a pathology here?
Distal ileum - if problem here then pernicious anaemia can develop. Need vit B12 to produce erythrocytes
Where are M cells found and what is their function?
Immune cells of Payer’s patches. Facilites transcytosis of bacterial pathogens and presents to immune cells
Why is apoptosis important in the mucosa of the small and large bowel?
Important to maintain the cellular balance in the crypts. Apoptosis happens close the the stem cells in the small intestine but further away in the large intestine- therefore higher risk of developin Ca as more abnormal cells escape programmed cell death
What is the unstirred layer of the GIT? What is its contents?
It functions to separate the lumen from the sub-epithelial space
Contains:
mucous –> binds bacteria
IgA –> binds bacterial antigen
CO3- –> neutralises luminal acids
Name the 4 transport mechanisms across the apical membrane of epithelial cells in the GIT mucosa
- Paracellular passive
- Trancellular active
- Transcellular passive
- Water transport (always passive)
Which part of the GIT is dysfunctional if high volume diarrhoea is seen?
Small intestine - it’s unable to absorbe a large amount of fluid
Which part of the GIT is dysfunctional if low volume diarrhoea is seen?
Large colon
What are the 3 roles of the intestinal flora?
- Assist in fermentation of faecal material
- Suppress overgrowth of pathogenic organisms
- Degrades intestinal mucins
What is dysentry?
Diarrhoea in small vols with blood. mucous and abdo pain
What is osmotic diarrhoea?
What is the ion gap?
Presence of an osmotically active substance in the gut lumen.
Ion gap >100mOsm/kg
What is secretory diarrhoea?
What is the osmotic gap?
Presence of e.g. bacterial toxin –> ion gap <100mOsm/kg i.e. no osmotically active substance in gut lumen
What is inflammatory diarrhoea?
Name 4 diseases where this is a symptom
Happens when the GIT is damages –> disordered stucture and function.
Increased secretion and malabsorption
Problem with digestion so larger molecules are found lower down the GIT
Coeliac, IBS, Crohns, Food intolerance
Name 4 symptoms of inflammatory bowel disease
Pain
Infection
Bloody mucoid stools (diarrhoea)
W/L
How is E. Coli 0157 transmitted?
Throught ingestion of <10 organisms after contaminated uncooked meat (sometimes diary and vegetables).
Can also be transmitted through contaminated faeces
What is HUS and which bacteria can cause it?
(Haemolytic-uraemic syndrome) haemolytic anaemia and renal failure - E. coli 0157
What is TTP? Which group are most likely to develop this after an E.coli infection of the GIT?
Thrombotic thrombocytopaemic purpura
OAPs
How is campylobacter transmitted?
Through uncooked poultry - lives in the GIT of birds and mammals
What is the contents of ORS?
H2O
Glucose
NaCl
What is the MOA of ORS?
Glucose and Na taken into enterocytes by Na driven glucose transporter - this draws water into the cells via osmotic gradient.
What is the dose of ORS?
1 sachet in 200ml initially and 200 ml following every loose stool
When would loperamide be an appropriate treatment for diarrhoea?
For travellers diarrhoea –> never in people where there is potential damage to the GIT - perforation is a risk here
What drug class is loperamide and what is its MOA?
Opioid receptor agonist.
Decreases motility of the bowel by decreaseding longitudinal muscle activity and increasing tone of anal sphincter –> increases absorption.
SE : can act systemically causing drowsiness (morphine and codeine act on the same receptors)
What is the immediate Tx of shock?
What are the risks here?
- ABCs
- Give O2
- IV / intraosseus line
- IV infusion of 20ml/kg NaCl 0.9% or Hartmanns
- Monitor and repeat if signs persist
Overhydration is a risk –> tachycardia, crackles in lung field, resp distress, hepatomegaly, oedema
Hypernatraemic dehydration is another risk of Tx for shock.
- What is it?
- What are the symptoms?
- What is the Tx?
- When Na >150mmol/L
- Jittery movements
- Increased muscle tone
- Hyper-reflexia
- Convulsions
- Drowsiness/coma
- Need to reduce the serum Na slowly and measure frequently. i.e. give 0.45% NaCl over a short time or 0.9% NaCl over a long time
Following the initial Tx of shock, how much fluid should be given IV to treat dehydration?
100ml/kg/day
Name 4 RF for dehydration in children
- <1 year old
- Low birth weight
- Fluid not tolerated/offered
- Cessation of breast feeling during illness
- >5 stools in 24hrs
What is the advice given about the nutritional management of acute diarrhoea in children?
During rehydration therapy - continue breastfeeding but don’t give solids. After rehydration therapy, re-introduce solid foods and avoid fruit juices
What is SAM and what are the signs?
Severe acute malnutrition
- Muscle wasting and decreased sub cut fat
- Angular stomatitis
- Smooth tongue
- Conjunctival/palmae pallor
- Skin hypo/hyperpigmentation
What are the risks of fluid management in SAM?
IV fluids could cause HF and death
Total [Na] is highg and there’s decreased cardiac reserve. Also leaky endothelium`
Name 5 signs of dehydration (8 listed)
- Appears unwell/deteriorating
- Altered responsiveness
- Decreased urine output
- Sunken eyes
- Dry mucous membranes
- Tachycardia
- Tachypnoea
- Decreased skin turgor
Name 4 signs of shock (6 listed)
- Decreased AVPU
- Pale/mottles skin
- Cold extremities
- Weak peripheral pulses
- Prolonged CRT
- Hypotension
i.e. all hypoperfusion