Term
| how do parietal cells help in defense for mucous? |
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Definition
as parietal cells take in Hydrogens and Chlorines they expel HCO3- which goes into the blood vessels to the mucous and acts as a buffer barrier to increase protection
adversely: the less blood flow, the more HCO3- buildup, the less buffer which leads to a decrease in protection |
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Term
| which glands have the deepest pits? |
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Definition
pyloric: deep pits and short glands
components: branched tubular glands, mucous cells PAS+, enteroendocrine cells and few parietal cells. Also have G-cells that secrete gastrin |
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Term
| What is Zollinger-Ellison Syndrome? |
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Definition
| caused by a gastrin-secreting tumor that may arise in the duodenum, pancreas, or peripancreatic soft tissue |
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Term
| Plicae circulares are not permanant folds. T/F? |
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Definition
| False, they are permenant, located in duodenum, jejunum, and fade away at distal ileum. They slow chyme down to increase absorbtion and enzymatic affects. |
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Term
| how much do villi and microvilli increase surface area? |
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Definition
villi x10
micro villi x20 |
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Term
| valves of kerckring are also called? |
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Definition
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Term
| what is important about the lamina propria in the intenstines, yet is not well-developed in the stomach? |
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Definition
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Term
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Definition
| absorb lipids from fatty foods, they engorge themselves with fat and then they appear white |
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Term
| why are villus rich with lymphocytes? |
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Definition
| the GI tract is in a constant controlled inflammatory state due to the antigens we eat daily |
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Term
| if you walked on the microvilli what would you fall into? |
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Definition
intestinal glands called crypts of lieberkuhn.
lined by simple columnar. the openings of glands are between the villi, classified as simple tubular glands.
intestinal glands contain: paneth cells that secrete lysozyme, defenisns and TNF |
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Term
| where are stem cells located in the stomach and intestines? |
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Definition
| stem cells are in the base in the intestine, but in the stomach they are in the isthmus/upper neck and they can differentiate and go up or down |
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Term
where are paneth cells located?
what do they secrete? |
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Definition
located in the intestinal glands (crypts of Lieberkuhn)
secrete lysozymes which are antimicrobial and defensins, and tumor necrosis factor
located in same area you will see goblet cells
enteroendocrine cells: located at basal side
and undifferentiated cells |
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Term
| where are Brunner glands located? |
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Definition
| in the proximal duodenum that secrete mucus, for protection of acid, and urogastrone (human epidermal growth factor) regulates cell turnover and inhibits parietal cell secretion, so when duodenum receives |
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Term
| Which wall of the small intestines is thicker and more vascularized? |
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Definition
jejunum is thicker and more vascularized, hence the jejunum is redder
since ileum doesn't have plicae circularis the walls are thinner. |
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Term
| Where are peyers patches found? |
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Definition
ileum
peyers patches have M-cells that can endocytose antigens and present them to the basal cells and trigger an immune response
such as gluten wheat in the intestines |
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Term
| structures of small intestines |
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Definition
mucosa: epithelium, columnar cells, microvilli, junctional complexes, goblet cells, lamina propria (well endowed with lymphatic vessels and intestinal crypts, muscularis mucosae
Intestinal glands:paneth cells, enteroendocrine cells, undifferentiated cells
Submucosa: moderately dense connective tissue, para and sympathetic postganglionic fibers, lymph vessels
Muscularis Externa: inner circular layer of SM, outer longitudinal layer, Auerbach's plexus between circular and longitudinal layers |
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Term
| what is different about the longitudinal band in the large intestines? |
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Definition
| the muscularis externa's outer longitudinal layer only has three strains called teniae coli |
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Term
| if you go towards or away from the ileum, goblet cells increase? |
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Definition
towards,
they also increase as you move distally in the large intestines because intestinal glands increase in number and size to increase absorbtion of water in large intestines so you need more mucus from goblet cells for the fecal matter due to its rougher surface |
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Term
| do the large intestines have villi and plicae circularis'? |
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Definition
| no, but they have irregular microvilli with ill =-define striated brush border |
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Term
| can you see paneth cells in large intestines? |
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Definition
| a few in the proximal end, right colon, but not in the distal |
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Term
| are there lymphatic vessels in the lamina propria in large intestines? |
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Definition
| no, they are located in teh submucosa. |
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Term
| appendix is just like the large intestine, but one major structure is different |
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Definition
| it has 2 complete layers of SM, a inner circular and an outer longitudinal, both are complete |
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