Flashcards in Highison: Small and Large Intestine Deck (52)
Layers of the small intestine
muscularis externa (inner circular outer longitudinal)
How long is the small intestine?
Principle site of digestion of food and absorption of products of digestion
3 "gross" aspects of the small intestine
Surface modifications increase the surface area of the small intestine by 400-600 times! What are three modifications that account for this increase?
1. plicae circulares (2-3x)
2. intestinal villi (10x)
3. microvilli (20x)
Projections/folds of the mucosa of the small intestine into the lumen. Increase absorptive surface of the mucosa.
Found in the lamina propria of the small intestine
crypts of Lieberkuhn
permanent spiral folds of mucosa and submucosa in distal duodenum, jejunum, and proximal ileum
What kind of epithelium is the mucosa of the small intestine?
Surface absorptive cells, specialized for transport of substances from intestinal lumen into circulatory system
Enterocytes of the mucosa of the small intestine have (blank) to increase apical surface area, and (blank) to seal off the intercellular space from the intestinal lumen
microvilli; intercellular junctions
Six cell types found in the mucosa of the small intestine
1. surface absorptive cells (enterocytes)
2. goblet cells
3. M cells
4. enteroendocrine cells
5. Paneth cells
6. stem cells
These cells secrete mucinogen that is converted to mucous for protection
These are antigen presenting cells, modified enterocytes. They cover lymphatic nodules in the lamina propria.
These cells produce nearly all the same peptide hormones that they do in the stomach
These cells secrete lysozyme and regulate normal intestinal flora
Where are Paneth cells primarily found?
in the distal ileum
These are regenerative cells that restore the epithelial cells every 5-6 days and the Paneth cells every 4 weeks
What do antimitotic drugs do for the small intestine?
create a higher rate of cell renewal
Occupies the villi and in between the intestinal glands (Crypts of Lieberkuhn)
What things are found in the lamina propria?
intestinal glands or crypts of Lieberkuhn
What are the lymphoid nodules of the ileum known as?
Submucosal glands (Brunner's glands) are found only in the (blank)
These glands are unique to the submucosa of the duodenum and produce alkaline mucin to neutralize HCl, and produce urogastrone that inhibits gastric HCl production.
Two things that Brunner's glands of the duodenum produce
Two layers of the muscularis externa of the lamina propria of the small intestine
inner circular, outer longitudinal
The most superficial layer of the small intestine is either (blank) or (blank)
Principle functions of the large intestine
reabsorption of electrolytes and water
elimination of waste
Parts of the large intestine
cecum, appendix, colon, rectum, anal canal