What is the function of the small bowel?
What are the functions of the large bowel?
Absorptive and secretory role
How long is the small bowel?
Approximately 6m long
How long is the duodenum?
What are the 3 parts of the small bowel?
What are the different parts of the large bowel?
How long is the rectum?
What are the different layers of the small bowel wall?
What are the layers of the mucosa in small bowel?
What cell types are in the mucosa of the small bowel?
Columnar absorptive cells
What is embedded within the mucosa of the small bowel?
Crypts that contain stem, goblet, endocrine and paneth cells
What are the projections from the epithelium of the small bowel?
What is the muscularis propria also known as?
How often is the wall of the small bowel renewed?
Every 4 to 6 days
What is different about the villi of the small bowel and the large bowel?
The large bowel does not contain any villi
What shape is the top of cells in the large bowel?
Flat, no villi
What shape are crypts in the large bowel?
What is the difference between crypts in the small intestine and large intestine?
Crypts in the large intestine do not contain paneth cells
What is a consequence of the GI tract having a large surface area?
Large exposure to environment antigens so immune system must balance harmless ingested substances against active defect reactions to potential microbial invaders
What does dysfunction of the intestinal immune system cause?
Life threatening acute conditions
What is small and large bowel peristalsis mediated by?
Intrinsic (myenteric) plexus and extrinsic (autonomic innervation) neural control
What is the myenteric plexus formed from?
Meissener's plexus (base of submucosa)
Auerbach plexus (between the inner circular and outer longitudinal layers of the muscularis propria)
Where is the Meissener's plexus found?
Base of submucosa
Where is the Auerback plexus?
Between the inner circular and outer longitudinal layers of the muscularis propria
What are examples of pathologies of the lower GI tract?
Inflammatory bowel disease (IBS)
Large bowel neoplasia
What does IBD stand for?
Inflammatory bowel disease
What is inflammatory bowel diseases the pathological feature of?
What is idiopathic inflammatory bowel disease?
Chronic inflammatory condition resulting from inappropriate and persistent activation of the mucosal immune system driven by the presence of normal intraluminal flora
What are the 2 main diseases of inflammatory bowel disease?
What is the difference in where Crohn's and ulcerative colitis can affect the GI tract?
Crohn's can affect ny part of the GIT from mouth to the anus
Ulcerative colitis is limited to the colon