Lab 9: digestive system II Flashcards
name parts of stomach - 4
fundus
cardia
body
pylorus
describe muscosa of stomach - gen
pits and glands
Epithelium
lamina propria
muscularis mucosa
Smooth muscle projections in between glands in lamina propria
describe epithelium (muscosa of stomach)
simple columnar epithelium - surface mucous cells
describe lamina propria (muscosa of stomach)
loose irregular ct
describe muscularis mucosa (muscosa of stomach)
2 layers of smooth muscle = inner circular and outer longitudinal
sometimes 3 layers - outer circular
describe submuscosa of stomach
dense irregular ct
no glands
rich in blood vessels, lymphatic’s and nerves
describe tunica muscularis of stomach
3 layers of smooth muscle = inner oblique, middle circular, outer longitudinal
describe serosa of stomach
thin layer of loose ct covered by a mesothelium - simple squamous epithelium
what is unique to stomach
pits and glands
describe glands (of pits and glands)
glands are simple and unbranched
how are pits and glands connected
connected to each other via an isthmus/neck
describe pits
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
describe isthmus/neck region
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
describe what lamina propria does (glands)
fills in space between glands
describe parietal cells
in neck and base of gland
very eosinophillic and round
central nucleus (fried egg)
describe zymogenic cells
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)
what is function of parietal cells
secrete HCl
what is function of zymogenic cells
zymogen granules containing digestive enzymes
like lipases and pepsin
which cell types do we not have to identify
stem cells
enteroendocrine cells - requires special staining
describe plyoric region
ratio of pits to glands 2:1
mucigen droplets
transition to mucous neck cells (more pyramidal)
describe body ratio
gastic region
pits to glands 1:4
new cells seen in region = parietal and zymogenic (chief) cells
which cells are present in neck region and which cells are not
parietal cells are present in neck region
zymogenic cells are not present in neck region
describe muscosa of small intestine - gen
crypts and villi
epithelium
lamina propria
muscularis mucosa
describe epithelium of SI mucosa
simple columnar epithelium with brush border
describe lamina propria of SI mucosa
loose irregular ct
describe muscularis mucosa of SI mucosa
2 layers of smooth muscle = inner circular and outer longitudinal
describe submucosa of SI
dense irregular ct
brunner’s glands = mucous, only in duodenum
plicae circularis = seen in jejunum
describe tunica muscularis of SI
2 layers of smooth muscle = inner circular and outer longitudinal
describe adventitia/serosa of SI
adventitia = dense irregular ct
serosa = thin layer of loose ct covered by mesothelium (simple squamous epithelium)
describe duodenum of SI
can distinguish based on brunner’s glands = located in submucosa, mucous secreting glands
name cell types found in SI villi
enterocytes
goblet cells
crypt base cells
paneth cells
describe lamina propria of SI villi
loose irregular ct
contains smooth muscle fibers to increase motility
describe enterocytes
identify in villi
columnar shaped cell
oval nucleus at base of cell
has brush border made of microvilli (NOT CILIA)
describe goblet cells
identify in villi
found throughout SI but more common distally
describe crypt base cells
do not need to identify
found in base of crypts - stem cells
describe paneth cells
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
describe jejunum of SI
no brunner’s glands but there is plicae circularis = resembles christmas tree
describe ileum of SI
no brunner’s glands
no visible plicae circularis
more goblet cells
few paneth cells
crypts and villi appear straight
payers patches - lymph
describe muscosa of large intestine - gen
no villi - only crypts (appear very straight, no paneth cells)
epithelium
lamina propria
muscularis mucosa
describe epithelium of LI mucosa
simple columnar
contains mainly goblet cells
describe lamina propria of LI mucosa
loose irregular ct
like SI
describe muscularis mucosa of LI mucosa
2 layers = inner circular and outer longitudinal
like SI
describe submucosa of LI
poorly preserved because very dense
no plicae circularis
describe tunica muscularis of LI
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
describe serosa of LI
thin layer loose ct covered by mesothelium (simple squamous epithelium)
what are plicae circularis
projections of ct from submucosa that fold and cause folds in mucosa
name cells found in brushborder of SI epithelium (mucosa)
enterocytes
goblet cells
paneth cells
crypt base cells
enteroendocrine cells
what is function of paneth cells
secrete lysozyme - breakdown bacterial cell walls
