General Flashcards
Causes of gastro-intestinal malabsorption
Decrease in bile Pancreatic insufficiency Small bowel mucosa Bacterial overgrowth Infection Intestinal hurry
Examples of diseases of intestinal malabsorption common in UK
Crohns
Coeliac
Chronic pancreatitis
GI malabsorption: Causes of decreased bile
Primary Biliary cholangitis
Ileal resection
Biliary obstruction
Colestyramine
GI malabsorption: Causes of pancreatic insufficiency causing GI malabsorption
Pancreatic cancer
Cystic fibrosis
GI malabsorption: Causes of Bacterial overgrowth causing malabsorption
Spontaneous in elderly
Jejunal diverticula
Post-op blind loops
Diabetes M and PPI are risk factors
Treat Bacterial overgrowth causing GI malabsorption
Metronidazole
GI malabsorption: Causes of Infection causing malabsorption
Giardiasis
Cryptosporidium
Diphyllobothriasis (B12 malabsorption)
Strongyloidiasis
GI malabsorption: Causes of Small bowel mucosa causing malabsorption
Whipple's disease Radiation enteritis Tropical sprue Brush border enzyme deficiencies e.g. lactase insufficiencies Drugs (Metformin, alcohol)
GI malabsorption: Causes of intestinal hurry causing malabsorption
Post-gastrectomy dumping
Post-vagotomy
Gastrojejunostomy
Symptoms of GI malabsorption
Diarrhoea Decreased weight Lethargy Steatorrhoea Bloating
Deficiency signs (of GI malabsorption)
Anaemia (low iron, B12, folate) Bleeding disorders (decreased Vitamin K) Oedema (decreased protein) Metabolic bone disease (decreased vitamin D) Neurological features e.g. neuropathy
Tests of GI malabsorption
(FBC)
Stools
Breath hydrogen analysis (for bacterial overgrowth)
Endoscopy + small bowel biopsy
GI malabsorption expected FBC results
low Ca2+
low Fe
low B12 + folate
increased INR
Describe stool test of GI malabsorption
Sudan stain for fat globules Stool microscopy (infection)
How does tropical sprue cause infectious malabsorption
Villous atrophy
What could you give for infection causing GI malabsorption
Tetracycline
Causes of splenomegaly
- Liver disease (cirrhosis, hepatitis)
- Acute or chronic infection (bacterial endocarditis, infectious mononucleosis, HIV, malaria, tuberculosis, histiocytosis)
- Hematologic malignancy (lymphomas, leukemias, myeloproliferative disorders)
- Congestion (splenic vein thrombosis, portal hypertension, congestive heart failure)
- Inflammation (sarcoidosis, lupus, rheumatoid arthritis, systemic lupus)
- Splenic sequestration (pediatric sickle cell, hemolytic anemias, thalassemias)
What is dyspepsia
One or more of following:
- Postprandial (after eating) fullness
- Early satiation
- Epigastric pain or burning for more than 4 weeks
Red alarm flag symptoms for cancer
- Unexplained weight loss
- Anaemia
- Evidence of GI bleeding e.g. melaena (dark tar like black stools) or haematemesis
- Dysphagia
- Upper abdominal mass - Persistent vomiting
Management of dyspepsia
- Reassurance
- Dietary review
- Antidepressants e.g. selective serotonin reuptake inhibitors e.g. CITALOPRAM (low doses are use to reduce the sensitivity of the gullet)
- Look for Helicobacter pylori using faecal antigen testing or breath test (less common now)
- Endoscopy to find clear picture of whats going on
How many layers does the smooth muscle wall of the stomach have
3
What are 3 layers of smooth muscle of the stomach called
(Outer) Longitudinal
Inner Circular
(Innermost) Oblique
What are 2 sphincters of stomach called
Gastro-oesophageal sphincter
Pyloric sphincter
Which smooth muscle layer of the stomach makes up most of the pyloric sphincter
Circular muscle layer thickening makes up most of pyloric sphincter
Controls exit of gastric contents into the duodenum
How many smooth muscle layers does the duodenum have and what are they called
2
Outer longitudinal
Inner smooth muscle
What shape is duodenum and where does pancreas sit in relation
C-shaped
Pancreas sits in the concavity
Where does duodenum end
Duodenojejunal flexure, where it becomes the jejunum
What are the names of the thick folds of the greater curvature of the stomach (that allow extension)
Rugae
What specialised cells are found in upper 2/3s of the stomach
Parietal cells
Chief cells
Enterochromaffin-like cells (ECL cells)
What is secreted by parietal cells
HCl and intrinsic factor
What is secreted by chief cells
Pepsinogen
initiates proteolysis
Enterochromaffin-like cells - what do they secrete
Histamine (stimulates acid release)
What are the different zones of the stomach
Cardia (Where GO sphincter is)
Fundus (above gastro-oesophageal sphincter)
Body
(Pyloric) Antrum (second last bit before the duodenum)
Pylorus (last bit before duodenum)
What cells are found in antral mucosa of stomach
Mucus secreting cells
G cells
D cells
What 2 chemicals are secreted by mucus secreting cells
Mucin
Bicarbonate
What is released by G cells
Gastrin (stimulates acid release)
What is released by D cells
Somatostatin (suppresses acid secretion)
What makes up the mucosal barrier (stomach)
Plasma membranes of mucosal cells and mucus layer (made up of mucin)
What is purpose of mucosal barrier of stomach
Protects gastric epithelium from damage by acid as well as alcohol, aspirin, NSAIDs and bile salts
What is effect of prostaglandins on mucus secretion
Stimulate mucus secretion
What drugs can inhibit synthesis of prostaglandins and thus mucus secretion
Aspirin
NSAIDs
What enzyme is inhibited by Aspirin and NSAIDs to prevent prostaglandin synthesis and thus mucus release
Cyclo-oxygenase (1)
What specialised cell is found in duodenal mucosa only
Brunner’s glands
What is secreted by Brunner’s glands in duodenum
Alkaline mucus
What helps neutralise acid secretion form stomach in duodenum
Pancreatic and biliary secretions (bile salts etc)
Alkaline mucus from Brunner’s glands
What is general function of prostaglandins
In inflamed tissue, prostaglandin triggers inflammatory response (thus inhibition means less inflammation).
Mucus secretion stimulated by prostaglandins.
2 types of peritoneum
Parietal - covered abdominal wall
Visceral - on organs e.g. stomach, liver and colon
Describe innervation and sensation of parietal peritoneum
Somatic innervation
Sensation is well localised
Describe innervation and sensation of visceral peritoneum
Autonomic innervation
Sensation is poorly localised
Site of autonomic pain from foregut
Epigastric
Site of autonomic pain from midgut
Periumbilical
Site of autonomic pain from hindgut
Hypogastric
Peritoneal cavity is a closed sac lined by what cells?
Mesothelial cells
What do mesothelial cells of peritoneal cavity secrete
Surfactant
acts as a lubricant within the peritoneal cavity
How much fluid and protein/transudate is found within the peritoneal cavity
<100ml serous fluid
<30g/L protein (transudate)
Where does fluid from the peritoneal cavity drain?
1/3 drains through lymphatics
Remainder through the parietal peritoneum
(particulate matter can be rapidly removed)
What is the start and end of foregut
Lower oesophagus to D2 (liver, spleen and gallbladder)
What is the start and end of the midgut
D2 to 2/3s across Transverse Colon (majority of abdomen)
What is the start and end of the hindgut
Last 1/3 of Transverse colon to Upper rectum
