Intestine

Question 1

increase in surface area ?

Answer 1

microvilli
villi
plicae circulares

Question 2

microvlli

Answer 2

cytoplasmic projections of cell membrane

striate border of simple columnar epithelium

Question 3

villi

Answer 3

evaginations of mucosa with core of lamina propria
-distinguishing characteristic of small intestine

multicellular structures

exclusively in small intestine

Question 4

villi in duodenum

Answer 4

broad, short, leaf like

Question 5

villi in jejunum

Answer 5

tongue-like projections

Question 6

villi in ileum

Answer 6

all, narrow, finger like projections

Question 7

plicae circulares

Answer 7

circular folds of entire mucosa, with core of submucosa**

permanent projections into lumen

Question 8

where do plicae circulares begin?

Answer 8

proximal duodenum

maximized in distal duodenum and proximal jejunum

diminish until absent in distal half of ileum

Question 9

exocrine glands

Answer 9

pancreas

liver

Question 10

submucosal glands

Answer 10

duodenal glands (brunners glands)
-in submucosa of duodenum

secrete mucous

Question 11

brunners glands

Answer 11

duodenal submucosa glands

secrete slightly basic mucous

Question 12

small intestine

Answer 12

submucosa has basic mucous producing

-to neutralize the acidic stomach content

Question 13

liver excretion

Answer 13

bile - to emulsify fats

Question 14

pancreas excretion

Answer 14

enzymes primarily in peptide degradation

Question 15

intestinal crypts

Answer 15

mucous secreting glands in small intestine

-epithelium invaginations into lamina propria in small and large intestine

Question 16

epithelium of small intestine

Answer 16

simple columnar epithelium replaced every 3 to 7 days

Question 17

cell types in epithelium of small intestine

Answer 17

absorptive columnar cells
goblet cells
lymphocytes
enteroendocrine cells
paneth cells
M cells

Question 18

goblet cells

Answer 18

secretes mucous

Question 19

as we move down GI tract?

Answer 19

number of goblet cells increase

Question 20

enteroendocrine cells in epithelium of small intestine?

Answer 20

mainly in crypts

• rarely in villus
• secrete products into vasacular channels in lamina propria

Question 21

K-cells

Answer 21

secrete incretins

enteroendocrine cell of small intestine epithleium

Question 22

L-cells

Answer 22

secrete GIP

enteroendocrine cell of small intestine epithelium

Question 23

enterochromaffin cells

Answer 23

secrete serotonin

enteroendocrine cells of small intestine epithelium

Question 24

products of enteroendocrine cells in GI tract?

Answer 24

incretin
GIP
serotonin
somatostatin
motilin
cholecystokinin
neurotensin
VIP
substance P
endorphins

going to basal layer*** (not lumen)

Question 25

somatostatin

Answer 25

stimulates homeostasis

Question 26

paneth cells

Answer 26

secretions go out into lumen produce lysozymes and defensins -help degrade bacterial cell walls in the epithelium of small intestine in base of intestinal crypts -contain large acidophilic granules

Question 27

M cell

Answer 27

in epithelium of small intestine -part of innate and classic immune systems capture and transport antigens to APCs and B cells in lamina propria likely located where there is a sharp fold in the villus border**

Question 28

mucosa of small intestine

Answer 28

lamina propria - loose CT - prone to lymphoid infiltration - lots of plasma cells (in villus between crypts) secretory IgA lymphatic capillaries - lacteals

Question 29

plasma cells

Answer 29

B lymphocytes | -antibody producing cells

Question 30

histiocyte

Answer 30

macrophage in the gut lining

Question 31

lacteals

Answer 31

lymphatic capillaries of the mucosa of small intestine

Question 32

where do lymphatics originate?

Answer 32

blind ending channels in the villi of the intestine -aka lacteals not only place, but an important one pick up emulsified fat lacteals have no red blood cells**

Question 33

peyers patches

Answer 33

in small intestine - lymphoid tissue that has become nodular in nature - like a lymph node in lamina propria of small intestine mucosa prominent in ileum may appear in lower jejunum

Question 34

more M cells present where?

Answer 34

peyers patches

Question 35

submucosa of small intestine?

Answer 35

projects into plicae circularies

Question 36

auerbachs plexus

Answer 36

between layers of muscularis externa in intestine -inner circular/outer longitudinal PS ganglia - maintain muscle tone

Question 37

myenteric plexus

Answer 37

on vascular channels | -dilation/constriction

Question 38

serosa of duodenum

Answer 38

on anterior surface only -organ is retroperitoneal posterior is adventitia

Question 39

ileocecal junction

Answer 39

site where ileum joins large intestine - formed by bolds of mucosa and submucosa - supported by mass of circular smooth muscle from muscularis externa

Question 40

cecum

Answer 40

small, blind pouch of large intestine | -structurally indentical to colon

Question 41

appendix

Answer 41

slender, blind diverticulum of cecum -small, irregular lumen often containing cellular debris villi are absent** intestinal crypts - enteroendocrine cells and some paneth cells

Question 42

large intestine?

Answer 42

lack villi as means of surface amplication**

Question 43

goblet cells in large intestine?

Answer 43

lots and lots because we are absorbing nutrients and water -so we have less and less hydrated material needs increased mucous production to help move along

Question 44

paneth cells?

Answer 44

mainly in small intestine

Question 45

crypts of lieberkuhn

Answer 45

intestinal crypts of large intestine | -larger and more closely packed than in small intestine

Question 46

cells of large intestine?

Answer 46

crypts of lieberkuhn enteroendocrine cells paneth cells

Question 47

epithelium of large intestine?

Answer 47

identical to small intestine - simple columnar epithelium - more numerous goblet cells virtually no digestive enzymes mainly water reabsorption

Question 48

placa circulares

Answer 48

not present in large intestine

Question 49

plica semilunares

Answer 49

present in the colon