Lab 9: digestive system II

Question 1

name parts of stomach - 4

Answer 1

fundus
cardia
body
pylorus

Question 2

describe muscosa of stomach - gen

Answer 2

pits and glands
Epithelium
lamina propria
muscularis mucosa
Smooth muscle projections in between glands in lamina propria

Question 3

describe epithelium (muscosa of stomach)

Answer 3

simple columnar epithelium - surface mucous cells

Question 4

describe lamina propria (muscosa of stomach)

Answer 4

loose irregular ct

Question 5

describe muscularis mucosa (muscosa of stomach)

Answer 5

2 layers of smooth muscle = inner circular and outer longitudinal
sometimes 3 layers - outer circular

Question 6

describe submuscosa of stomach

Answer 6

dense irregular ct
no glands
rich in blood vessels, lymphatic’s and nerves

Question 7

describe tunica muscularis of stomach

Answer 7

3 layers of smooth muscle = inner oblique, middle circular, outer longitudinal

Question 8

describe serosa of stomach

Answer 8

thin layer of loose ct covered by a mesothelium - simple squamous epithelium

Question 9

what is unique to stomach

Answer 9

pits and glands

Question 10

describe glands (of pits and glands)

Answer 10

glands are simple and unbranched

Question 11

how are pits and glands connected

Answer 11

connected to each other via an isthmus/neck

Question 12

describe pits

Answer 12

covered by surface mucous cells
the stomach lining is made up of this cell type
columnar in shape and have basally located nucleus that is ovoid in shape
apex of cell is filled with mucigen droplets (poorly stained with H&E)
cells are not goblet shaped

Question 13

describe isthmus/neck region

Answer 13

glands narrow
have mucous neck cells present (like surface mucous cells but more pyramidal than columnar shape)
have stem cells (different from SI, result=bi directional orientation of differentiation)
glands are all made of mucous cells

Question 14

describe what lamina propria does (glands)

Answer 14

fills in space between glands

Question 15

describe parietal cells

Answer 15

in neck and base of gland
very eosinophillic and round
central nucleus (fried egg)

Question 16

describe zymogenic cells

Answer 16

accumulate at base of gland
columnar shaped cell with ovoid nucleus (basally located so base appears basophilic)
apex of cell is filled with zymogen granules (eosinophilic, often poorly fixed)

Question 17

what is function of parietal cells

Answer 17

secrete HCl

Question 18

what is function of zymogenic cells

Answer 18

zymogen granules containing digestive enzymes
like lipases and pepsin

Question 19

which cell types do we not have to identify

Answer 19

stem cells
enteroendocrine cells - requires special staining

Question 20

describe plyoric region

Answer 20

ratio of pits to glands 2:1
mucigen droplets
transition to mucous neck cells (more pyramidal)

Question 21

describe body ratio

Answer 21

gastic region
pits to glands 1:4
new cells seen in region = parietal and zymogenic (chief) cells

Question 22

which cells are present in neck region and which cells are not

Answer 22

parietal cells are present in neck region
zymogenic cells are not present in neck region

Question 23

describe muscosa of small intestine - gen

Answer 23

crypts and villi
epithelium
lamina propria
muscularis mucosa

Question 24

describe epithelium of SI mucosa

Answer 24

simple columnar epithelium with brush border

Question 25

describe lamina propria of SI mucosa

Answer 25

loose irregular ct

Question 26

describe muscularis mucosa of SI mucosa

Answer 26

2 layers of smooth muscle = inner circular and outer longitudinal

Question 27

describe submucosa of SI

Answer 27

dense irregular ct brunner's glands = mucous, only in duodenum plicae circularis = seen in jejunum

Question 28

describe tunica muscularis of SI

Answer 28

2 layers of smooth muscle = inner circular and outer longitudinal

Question 29

describe adventitia/serosa of SI

Answer 29

adventitia = dense irregular ct serosa = thin layer of loose ct covered by mesothelium (simple squamous epithelium)

Question 30

describe duodenum of SI

Answer 30

can distinguish based on brunner's glands = located in submucosa, mucous secreting glands

Question 31

name cell types found in SI villi

Answer 31

enterocytes goblet cells crypt base cells paneth cells

Question 32

describe lamina propria of SI villi

Answer 32

loose irregular ct contains smooth muscle fibers to increase motility

Question 33

describe enterocytes

Answer 33

identify in villi columnar shaped cell oval nucleus at base of cell has brush border made of microvilli (NOT CILIA)

Question 34

describe goblet cells

Answer 34

identify in villi found throughout SI but more common distally

Question 35

describe crypt base cells

Answer 35

do not need to identify found in base of crypts - stem cells

Question 36

describe paneth cells

Answer 36

restricted to base of crypts found throughout SI - becomes less frequent distally (none in colon) large pyramidal shaped cells base of cell is basophilic = rich in RER apex of cell = eosinophilic since filled with granules

Question 37

describe jejunum of SI

Answer 37

no brunner's glands but there is plicae circularis = resembles christmas tree

Question 38

describe ileum of SI

Answer 38

no brunner's glands no visible plicae circularis more goblet cells few paneth cells crypts and villi appear straight payers patches - lymph

Question 39

describe muscosa of large intestine - gen

Answer 39

no villi - only crypts (appear very straight, no paneth cells) epithelium lamina propria muscularis mucosa

Question 40

describe epithelium of LI mucosa

Answer 40

simple columnar contains mainly goblet cells

Question 41

describe lamina propria of LI mucosa

Answer 41

loose irregular ct like SI

Question 42

describe muscularis mucosa of LI mucosa

Answer 42

2 layers = inner circular and outer longitudinal like SI

Question 43

describe submucosa of LI

Answer 43

poorly preserved because very dense no plicae circularis

Question 44

describe tunica muscularis of LI

Answer 44

inner circular outer longitudinal - can be modified to form a 3rd layer that runs the length of the colon = taenia colon functions to strengthen longitudinal contractions

Question 45

describe serosa of LI

Answer 45

thin layer loose ct covered by mesothelium (simple squamous epithelium)

Question 46

what are plicae circularis

Answer 46

projections of ct from submucosa that fold and cause folds in mucosa

Question 47

name cells found in brushborder of SI epithelium (mucosa)

Answer 47

enterocytes goblet cells paneth cells crypt base cells enteroendocrine cells

Question 48

what is function of paneth cells

Answer 48

secrete lysozyme - breakdown bacterial cell walls