Lower GI I Flashcards
(27 cards)
What section of the small intestine are Brunner’s glands located?
In the duodenum
What section of the small intestine are deep crypts of Lieberkuhn located?
duodenum
What type of glands are crypts of Lieberkuhn?
simple tubular glands within the intestinal mucosa
What types of cells are within the crypts of the Lieberkuhn?
- goblet cells
- enterocytes
- paneth cells
- enteroendocrine cells
What cells within the crypts of Lieberkuhn secretes peptide hormones and serotonin?
Enteroendocrine cells
What cells of the crypts of Lieberkuhn have prominent eosinophilic granules?
paneth cells of the duodenum
What is the function of enterocytes within the crypts of Lieberkuhn?
- produce disaccharides
- involved in absorption of proteins, carbohydrates, and lipids
- enzymes for carbohydrate digestion
- produce enteropeptidase (enterokinase) for activation of pancreatic zymogens and proenzymes
What 3 sections makes up the small intestine?
- duodenum
- jejunum
- ileum
What type of epithelium is seen in the large intestine?
simple columnar without villi (they posses crypts)
What is the function of the large intestine?
-secretion of mucus for lubrication
-absorption of fluid
-formation of fecal mass
continuation of digestion initiated in small intestine.
What is appendix epiploica and where is it found?
masses of adipose tissue tat are enclosed within serosa. These are like fatty tags extending from the large intestine. Their purpose is unknown.
What are taeniae coli and where are they found?
Longitudinal muscles arranged around the perimeter of the large intestine in 3 large bands.
What section of the small intestine has leaflike shaped villi, include Brunner’s glands, and glands of Lieberkuhn?
duodenum of the small intestine
What section of the small intestine has finger-like shaped villi, lacks glands, but includes crypts of Lieberkuhn?
jejunum of the small intestine
What are Paneth cells responsible for secreting?
- lysozymes - degrades peptidoglycan coat of bacteria
- defensins - increases membrane permeability of target organisms.
- tumor necrosis factor - alpha - proinflammatory cytokine
What cells secrete mucosa?
goblet cells
What makes up the two layers of mucosa of the large intestine?
outer layer: microorganisms
inner layer: antimicrobial proteins (from paneth cells, enterocytes, and goblet cells) that resist microbial penetration
What type of cell(s) are toll-like receptors found on ?
toll-like receptors are found on the surface of enterocytes.
What is the purpose of toll-like receptors?
recognize structurally conserved molecules broadly shared by pathogens but distinguished from host molecules (pathogen associated molecular patterns)(PAMPS)
Name 3 permanent structures of the GALT.
- appendix
- Peyer’s patches
- Mesenteric lymph nodes
What is the purpose of high endothelial venules (HEVs) within Peyer’s patch?
facilitate entrance of lymphocytes into lymphoid organs from the bloodstream.
What cells secrete IgA and where?
IgA is synthesized and secreted by plasma cells in the lamina propria
Describe the rapid cell turnover mechanism within the esophagus and anus.
New cells are formed in basal layer of stratified epithelium and migrate through sub-basal levels to be sloughed off into the lumen.
Describe the rapid cell turnover mechanism within the small intestine.
New cells are formed in the crypts from undifferentiated cells.
