Alimentary System Facts Flashcards
How much is the total economic burden of alimentary disease on the NHS?
£8 billion
What is the pH of the stomach?
Lumen: pH 1-2
Epithelial surface pH 6-7
What is the common pathway causing gastric secretion?
Intramucosal histamine release
How do H2 inhibitors work?
Histamine acts on H2 receptors on parietal cells to stimulate secretion HCl. Ranitidine is a H2 blocker, and Omeprazole is a proton pump blocker, reducing gastric acid secretion.
What are the ridge-like longitudinal folds in the stomach called?
Rugae
What cells secrete pepsinogen, and what cells secrete HCl?
Pepsinogen is secreted by chief cells. HCl is secreted by partietal/oxyntic cells
How long is the small intestine and its constituents?
6m long. Duodenum is 25cm. Jejunum is 2.5m, ileum is 3.75m
How can the jejunum, ileum and duodenum be distinguished?
Duodenum contain Brunner’s glands
Jejunum have plicae circularis (large folds in mucosa)
Ileum have most Peyer’s patches
What is another name for the enteroendocrine cells of the small intestine?
Chromaffin cells
What is the life-span of an enterocyte?
1-6 days
What carrier proteins aid the absorption of carbohydrates from the small intestine?
SGLT-1 on apical membrane transports glucose or galactose, alongside a sodium ion.
GLUT-5 allows fructose to be absorbed by facilitated diffusion
GLUT-2 facilitates exit through basolateral membrane.
What are the two pathways for triglyceride formation inside enterocytes?
- Monoglyceride acetylation
- Phosphadic acid pathway
What are the components of GALT?
Intraepithelial lymphocytes, lamina propria lymphocytes, crytopatches, Peyer’s patches, isolated lymphoid follicles and mesenteric lymph nodes.
What are the subtypes of E.Coli that cause diarrhoea?
- Enterotoxigenic
- Enterohaemorrhagic
- Enteropathogenic
How is acute liver failure subdivided?
Hyperacute (
