Lab 10: Digestive system III Flashcards
how to distinguish structure of glands
tubular vs acinar
simple vs compound/branched
how to determine function of glands
endocrine vs exocrine vs paracrine
name types of secretion methods of glands
holocrine vs merocrine vs apocrine
describe product secreted out of gland
serous vs seromucous vs serous demilunes
describe tubular
gland and duct are continuous as tubular structures
describe acinar
alveolar
many grape looking structures secrete into a network of ducts
describe simple
sweat gland
describe compound
salivary gland
describe endocrine
no duct
product secreted directly into surrounding CT and diffuses to blood
describe exocrine
product is delivered to surface/lumen by means of a duct
describe paracrine
product is delivered to adjacent cells
describe holocrine
secretion product is entire cell
sebaceous gland
describe merocrine
membrane bound secretory granules are released from cell
salivary gland
describe apocrine
secretory products are released together with portions of secreting cell
describe serous secretion
watery and rich in glycoproteins
describe mucous
rich in carbohydrates
name glands which are serous
parotid
salivary gland
describe serous glands gen
small lumen
cells are tall and pyramidal
nuclei basally located and are spherical
base of cells are basophilic = rich in RER
apex is eosinophilic (zymogen granules)
watery and rich in glycoproteins
can be a serous or mucous mixture
describe serous gland - lobe specific
glands divided into lobes and subdivided into lobules
lobes divided by dense irregular ct
lobules divided by some ct (less than lobes)
very little ct around each acinus
describe mucous glands
larger lumen
pyramidal shaped cells
nuclei basally located and flattened in appearance
apex filled with poorly fixed mucinogen droplets
secretion rich in carbs
describe von ebners glands
exclusively serous
describe serous mucous glands
mixed acinus
mucous and serous cells can be I acinus or in different neighbouring acini
mucous with serous demilunes = mixture of mucous and serous, serous demilunes are serous cells that surround and rest on a mucous acinus
what are seromucous glands
mixture of both serous and mucous glands
what are glands
acini
describe serous demilunes
serous cells that surround and rest on a mucous acinus
describe salivary gland
parotid = serous
100% serous
other 100% serous gland = von ebner
branched acinar gland
describe submandibular gland
serous and serous mucous
90% serous and 10% mucous
compound tubol-acinar
intralobular
describe intralobular (submandibular gland)
found within the tubule
little ct around duct
can be intercalated or striated
describe sublingual gland
mucous
mainly mucous with some serous demilunes
compound tubulo acinar gland
small gland
interlobular duct
describe interlobular ducts (sublingual gland)
in between lobules
collecting ducts
ct visible around duct
describe intralobular ducts
as duct system enlarges = cells
become larger
intercalated duct —> striated duct —> collecting duct
describe intercalated duct
smallest
simple
squamous/cuboidal
always in lobule (intralobular)
describe striated duct
same size as acinus
cuboidal to columnar
cells interdigitate = indistinct lateral cell borders
striations (eosinophilic) = membrane infolding and mitochondria
describe collecting duct
largest
no striation
simple cuboidal to columnar
thick BM
INTERLOBULAR
describe parts of pancreas
exocrine = acinar pancreas
endocrine = islets of langerhans
describe exocrine pancreas
exclusively serous (key to distinguish from
salivary gland)
no striated ducts
centroacinar cells line part of the lumen of acini and are continuous with intercalated ducts (forms initial portion of intercalated ducts)
centroacinar cells diagnostic of pancreas
describe endocrine pancreas
exclusively endocrine
pale and circular
delineated by very little cr
contain a network of
fenestrated capillaries
do not need to distinguish cell types
describe features of pancreas
on serous (no mucous) + islet of langerhans
no striated duct in pancreas (has intercalated ducts and intralobular ducts (within lobules)) = another way to distinguish
name parts of liver
lobules
portal space/triad
describe liver lobules
poorly delineated
polyhedral
made of cords of hepatocytes
sinusoids converge on a central vein
describe liver portal space
hepatic arteriole
portal venule
common bile duct
choleangiole (at periphery)
describe cholangiole
simple cuboidal epithelium
describe hepatic sinusoids
discontinuous or fenestrated capillary with discontinuous BM
describe chords of hepatocytes
one cell thick
how many surfaces do hepatocytes have
2 distinct surfaces
describe the 2 surfaces of hepatocytes
one surface faces other hepatocytes and has a hemispherical indentation that helps form bile canaliculi
one surface that has microvilli and faces sinusoids (the space of disse is found here, it is an extracellular space between hepatocytes and sinusoids)
describe how sinusoids formed
from the portal space the portal venule and hepatic arteriole join to form sinusoids
where does blood from sinusoids go
blood from sinusoids goes to central vein (which will drain to larger hepatic veins that are not in portal spaces)
what is bile produced by
hepatocytes
how does bile move
bile moves through bile canaliculi into choleangioles and then bile ducts
describe bile ducts
cuboidal to columnar epithelium
much larger than choleangioles
how do blood and bile flow
In opposite directions
