alimentary immune functions Flashcards
immunological disorders: identify the symptoms, mechanisms, diagnosis and treatment/management associated with cholera infection, Crohn's disease, coeliac disease, irritable bowel syndrome, ulcerative colitis and infectious diarrhoea
3 symptoms of irritable bowel syndrome
recurrent abdominal pain, abnormal bowel motility, constipation/diarrhoea
how is irritable bowel syndrome (functional disorder) different to inflammatory bowel disease
inflammatory bowel disease also contains inflammation, ulcers and other damage
what type of abdominal pain is experienced in irritable bowel syndrome
visceral hypersensitivity
what is visceral hypersensitivity
sensory nerve endings in intestinal wall have abnormally strong response to stimuli (e.g. stetching after meal)
why do sufferers of irritable bowel syndrome have abnormal bowel motility
unabsorbed short-chain carbohydrates (lactose, fructose) act as solutes, drawing water into lumen, triggering visceral hypersensitivity and causing smooth muscles to spasm, creating diarrhoea if excess water not reabsorbed
how else might spasms or pain be caused in irritable bowel syndrome
unabsorbed short-chain carbohydrates metabolised by gastrointestinal bacterial flora, creating gas which causes spasms or pain
2 risk factors of irritable bowel syndrome
having had gastroenteritis (norovirus, rotavirus), stress
4 treatments of irritable bowel syndrome
diet modification, constipation, spasms and pain, management of stress, anxiety, depression
how is diet modified in irritable bowel syndrome
avoid certain foods with short-chain carbohydrates e.g. apples, beans, cauliflowers
how is constipation treated in irritable bowel syndrome
soluble fiber, stool softeners, osmotic laxatives
how are spasms and pain treated in irritable bowel syndrome
anti-diarrhoeals (serotonin antagonists), anti-muscarinic
3 symptoms of coeliac disease
abdominal distension (bloating), diarrhoea, sometimes dermititis herpetiformis
in coeliac disease, what is not broken down in the stomach
gliadin (33 amino acid peptide component of gluten)
fate of gliadin in coeliac disease
reaches small intestine and binds to secretory IgA in mucosal membrane
fate of gliadin-secretory IgA complex
binds to transferrin receptor (TFR) and transferred to lamina propria
what cuts of the amide group from the protein
enzyme tissue transglutaminase (tTG)
fate of deamidated gliadin
phagocytosed by macrophages and presented by MHC class II, causing destruction of epithelial cells due to activation of immune system
2 methods of diagnosis of coeliac disease
antibody blood tests (anti-gliadin, anti-tTG, anti-endomysial (EMAs)); biopsy test of duodenum
2 methods of dietary management of coeliac disease
gluten-free diet (wheat, barley, rye exclusion), medication