Histology of the GI Tract (In class)- Cole Flashcards Preview

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Flashcards in Histology of the GI Tract (In class)- Cole Deck (28)
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what is the purpose of villi?

to increase surface area and therefore absorption

1

What are the 4 degrees of folding?

1. plicae circulares (PC)
2. Intestinal villi
3. Intestinal glands (Crypts of Liberkuhn)
4. microvilli on surface of enterocytes

2

where are pilcae circulares present?

duodenum and disappear mid-ileum

3

what does the length of villi depend on?

degree of distention of intestinal wall and smooth muscle contraction

4

Instestinal glands are what kind of glands? what do they have a lot of?

simple, tubular glands with lots of goblet cells

5

What other cells are part of glands?

paneth and enteroendocrine cells

6

Microvilli have what on them?

a glycocalyx

7

What is segmentation and what does it serve to do? what controls it?

a pattern of annular contraction forms compartments, mixes chyme; ANS

8

Peristalsis is what?

coordinated contraction with relaxation of next section; pushes food thru

9

what is the beginning of the lymphatic system in the villi?

lacteals

10

what do lacteals collect from digested products?

chylomicrons

11

intrinsic input for innervation comes from?

mucosa and muscle wall of small intestine

12

extrinsic input for innervation comes from?

CNS thru vagus and sympathetic n. trunks

13

what distinguishing feature does the duodenum have histologically?

leaf-like villi, Brunner's glands (mucous glands), few goblet cells

14

Jejunum has what histologically?

lots of plicae circulares, irregular villi with finger-like shape, more goblet cells, no brunner's or peyer's patches

15

ileum has what histologically?

peyer's patches (collection of lymphoid tissue), SHORTER finger-like villi, most goblet cells, M cells (antigen presenters)

16

what are enterocytes? what do they have on top? these contain?

absorptive cells; microvilli- intermembranous enzymes to break carbs down to hexoses

17

what does gastrin do?

stimulates gastric motility, HCl (parietal cells) and insulin

18

what Ig is secreted by GALT?

IgA

19

what is the purpose of a fecal microbiota transplant?

replace good bacteria that has been killed or suppressed; prevents bad bacteria to overpopulate

20

major function of large intestine?

absorbs ions and water

21

what's a distinguishing feature of large intestine?

tenia coli

22

what does active transport of sodium do?

concentrates chyme into feces

23

what are the enterocytes of the large intestines job? what is it regulated by?

sodium and chloride absorption; mineral corticoids

24

what does aldosterone do to enterocytes?

increases number of Na channels

25

what does the appendix have to distinguish it?

lots of lymphoid tissue in walls

26

histologically what happens at the ano-rectal junction?

simple columnar to stratified squamous epithelium

27

what is the gene that can lead to familial polyposis?

APC