Histology of the GI Tract (In class)- Cole

Question 0

What are the 4 degrees of folding?

Answer 0

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

Question 1

what is the purpose of villi?

Answer 1

to increase surface area and therefore absorption

Question 2

where are pilcae circulares present?

Answer 2

duodenum and disappear mid-ileum

Question 3

what does the length of villi depend on?

Answer 3

degree of distention of intestinal wall and smooth muscle contraction

Question 4

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

Answer 4

simple, tubular glands with lots of goblet cells

Question 5

What other cells are part of glands?

Answer 5

paneth and enteroendocrine cells

Question 6

Microvilli have what on them?

Answer 6

a glycocalyx

Question 7

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

Answer 7

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

Question 8

Peristalsis is what?

Answer 8

coordinated contraction with relaxation of next section; pushes food thru

Question 9

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

Answer 9

lacteals

Question 10

what do lacteals collect from digested products?

Answer 10

chylomicrons

Question 11

intrinsic input for innervation comes from?

Answer 11

mucosa and muscle wall of small intestine

Question 12

extrinsic input for innervation comes from?

Answer 12

CNS thru vagus and sympathetic n. trunks

Question 13

what distinguishing feature does the duodenum have histologically?

Answer 13

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

Question 14

Jejunum has what histologically?

Answer 14

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

Question 15

ileum has what histologically?

Answer 15

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

Question 16

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

Answer 16

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

Question 17

what does gastrin do?

Answer 17

stimulates gastric motility, HCl (parietal cells) and insulin

Question 18

what Ig is secreted by GALT?

Answer 18

IgA

Question 19

what is the purpose of a fecal microbiota transplant?

Answer 19

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

Question 20

major function of large intestine?

Answer 20

absorbs ions and water

Question 21

what’s a distinguishing feature of large intestine?

Answer 21

tenia coli

Question 22

what does active transport of sodium do?

Answer 22

concentrates chyme into feces

Question 23

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

Answer 23

sodium and chloride absorption; mineral corticoids

Question 24

what does aldosterone do to enterocytes?

Answer 24

increases number of Na channels

Question 25

what does the appendix have to distinguish it?

Answer 25

lots of lymphoid tissue in walls

Question 26

histologically what happens at the ano-rectal junction?

Answer 26

simple columnar to stratified squamous epithelium

Question 27

what is the gene that can lead to familial polyposis?

Answer 27

APC