Digestive glands
General outline
? small digestive glands
? distributed in the wall of digestive tract
? esophageal glands,gastric glands and
?intestine glands
? large digestive glands
? outside the wall of digestive tract
? salivary glands,liver and pancreas
Large salivary glands
? Include parotid,submandibular and
sublingual glands
? are compound tubuloacinar glands
? are composed of acini and ducts
Acinus,
? acinar epithelium,simple
cuboidal or pyramidal cells
? myoepithelial cell
? basal membrane
Structure:
Be divided into
Serous acini
Mucous acini
Mixed acini
Serous acini
? cytoplasma are deep stained
? nucleus are spherical in shape and near
the base
? secretion is thin,contains salivary amylase
and a little mucus
Serous acini and striated duct
Mucous acini
? cytoplasma are light-blue stained
? nucleus are flattened ovoid shaped and
close to the base
? secretion is thick; contains mucoprotein
Mucous acini
Mixed acini
? consist of above two kinds of cells
? demilunes,several serous cells are
attached eccentrically to the mucous acini
Mixed acini
Ducts:
? Intercalated ducts
diameter,thinnest
wall,simple low cuboidal epithelium
? Striated duct (secretory duct)
?wall,simple columnar epithelium; the nucleus
is near the cell apex; cytoplasm is
acidpphilic; has basal striations
? EM,the basal striations created by
membrane infolding and mitochondia
? reabsorbing sodium and excreting potassium;
transport water and ions
Intercalated ducts and striated ducts
? Interlobular duct
Wall,pseudostratified epithelium
? Main duct
Near its orifice become stratified
squamous epithelium
Parotid gland
? pure serous gland
? longer intercalated duct
? secrete 25% of saliva,more salivary
amylase,less mucus
Parotid gland
Submandibular gland
? mixed gland,Serous acini are more than
mixed or mucous acini
? short intercalated duct,longer striated duct
? secrete 70% of saliva,less salivary amylase,
more mucus
Submandibular
gland
Sublingual gland
? mixed gland,mucous and mixed acini
predominant,more demilune
? without intercalated duct,obscure striated
duct
? secrete 5% of saliva,most mucus
Sublingual gland
Pancreas
Exocrine portion:
? the features of the acini
? a single layer of pyramidal serous cells
surrounded by basal lamina,without
myoepithelial cells
? centro-acinar cells,the epithelial cells of
intercalated duct penetrating into the
lumen of the acinus
? the feature of ducts
? the intercalated duct is long and has branches
? no striated duct
?main duct,lined by simple columnar
epithelium in which a few goblet cells
and endocrine cells can be seen
? The functions of exocrine portion
Secret abundant trypsinogen,
chymotrypsinogen,amylase,lipase,
sodium bicarbonate and trypsin inhibitor
Pancreas
Pancreas ( show centro-acinar cells
and intercalated ducts)
Endocrine portion (pancreatic islet):
? rounded clusters of cells embedded within
exocrine pancreatic tissue
? are divided into three kinds of cells,A,B,
and D cells
? fenestrated capillaries are among the
cells
Pancreas (show pancreatic islet)
Size number Distribution Function
A cells large 20% Peripheral glucagon
B cells small 75% center insulin
D cells 5% Among A and B cells somatostatin
Endocrine portion
Other cells
PP cells,pancreatic polypeptide
G cells,gastrin
A cells B cells
D cells
Liver
Liver lobule
Portal area
Hepatic plates
Sinusoid
Central vein
Interlobular arteries
Interlobular veins
Interlobular bile ducts
Functions of liver:
? bile secretion
? synthesize,protein,glycogen,cholesterin
? detoxification and inactivation
? defence
? hemopoiesis
Human liver
Pork liver
Liver lobule:
? hepatic plates,are composed of a single
layer of hepatocytes arranged in radial
? sinusoid,situated between the hepatic
plates,forming a complex network
? central vein,occupies the centre of the
liver lobule
Liver lobule
Hepatic
plates
Hepatic cords and liver sinusoids
Hepatocytes
? polyhedral in shape,eosinophilic cytoplasm,
one or two large rounded nuclei with one or 2
typical nucleoli
? EM,Mi,RER,SER,Golgi apparatus,
lysosomes,microbodies,inclusions
? Mitochondria
provide the energy for the hepatocytes
? Rough endoplasmic reticulum
synthesize some plasma proteins
? Golgi apparatus
participate in the formation of bile and
lipoprotein
? Smooth endoplasmic reticulum
? synthesize bile,triglyceride and LDL
? metabolism of the lipid,hormones and
cholerythrin
? inactivate steroid hormone
? biotransformation of some materials
? detoxification of noxious substances
? Lysosomes
? actively participate the metabolism of
hepatocyte and renewal of organelles
? play a role in metabolism and transport of
cholerythrin
? storage of iron
? Microbodies
detoxification,catalase and peroxidase;
reduce the hydrogen peroxide into H2O
? Inclusions
include glycogen,lipid droplets,pigment etc;
These contents vary according to physiologic
state of human body
Bile canaliculi
? between two adjacent hepatocytes
? the membrane of hepatocyte projects to
the lumen,forming many microvilli
? the cell membranes near the bile canaliculi
are firmly bound by junctional complexes
Bile canaliculi
Liver sinusoid
? spaces between the hepatic plates
? irregular in shape
? composed of only one discontinuous layer of
fenestrated endothelial cells,no diaphragm,
no basement membrane
? Kupffer cells are located within the sinusoid
cavities
Kuffer cells in liver sinusoid
Liver sinusoid
and space of
Disse
Space of Disse
? separates the endothelium from the
hepatocytes
? contains some reticular fibers and fat-storing
cells
Portal space:
? the connective tissue separating the lobules
? including
Interlobular arteries
Interlobular veins
Interlobular bile ducts
Portal spaces
Blood circulation:
portal V,interlobular V.
sinusoids
hepatic A,interlobular A.
central V.
sublobular V.
hepatic V.
（ functional vessel)
(nutrient vessel)
Blood vessels
of liver
(prepared Chinese
ink injection
through portal vein)
Discharge way of bile:
Bile canaliculi
Hering’s canals
Interlobular bile ducts
Hepatic duct
Common bile duct
Gallbladder
Cystic duct
duodenum
Gallbladder
? mucosa Simple columnar Epi.,no Goblet cells
Laminar propria,C.T.
? muscle layer,composed of an inner circular,
an outer longitudinal layers of smooth muscle
? adventitia,most are fibrosa,some are serosa
Gallbladder
General outline
? small digestive glands
? distributed in the wall of digestive tract
? esophageal glands,gastric glands and
?intestine glands
? large digestive glands
? outside the wall of digestive tract
? salivary glands,liver and pancreas
Large salivary glands
? Include parotid,submandibular and
sublingual glands
? are compound tubuloacinar glands
? are composed of acini and ducts
Acinus,
? acinar epithelium,simple
cuboidal or pyramidal cells
? myoepithelial cell
? basal membrane
Structure:
Be divided into
Serous acini
Mucous acini
Mixed acini
Serous acini
? cytoplasma are deep stained
? nucleus are spherical in shape and near
the base
? secretion is thin,contains salivary amylase
and a little mucus
Serous acini and striated duct
Mucous acini
? cytoplasma are light-blue stained
? nucleus are flattened ovoid shaped and
close to the base
? secretion is thick; contains mucoprotein
Mucous acini
Mixed acini
? consist of above two kinds of cells
? demilunes,several serous cells are
attached eccentrically to the mucous acini
Mixed acini
Ducts:
? Intercalated ducts
diameter,thinnest
wall,simple low cuboidal epithelium
? Striated duct (secretory duct)
?wall,simple columnar epithelium; the nucleus
is near the cell apex; cytoplasm is
acidpphilic; has basal striations
? EM,the basal striations created by
membrane infolding and mitochondia
? reabsorbing sodium and excreting potassium;
transport water and ions
Intercalated ducts and striated ducts
? Interlobular duct
Wall,pseudostratified epithelium
? Main duct
Near its orifice become stratified
squamous epithelium
Parotid gland
? pure serous gland
? longer intercalated duct
? secrete 25% of saliva,more salivary
amylase,less mucus
Parotid gland
Submandibular gland
? mixed gland,Serous acini are more than
mixed or mucous acini
? short intercalated duct,longer striated duct
? secrete 70% of saliva,less salivary amylase,
more mucus
Submandibular
gland
Sublingual gland
? mixed gland,mucous and mixed acini
predominant,more demilune
? without intercalated duct,obscure striated
duct
? secrete 5% of saliva,most mucus
Sublingual gland
Pancreas
Exocrine portion:
? the features of the acini
? a single layer of pyramidal serous cells
surrounded by basal lamina,without
myoepithelial cells
? centro-acinar cells,the epithelial cells of
intercalated duct penetrating into the
lumen of the acinus
? the feature of ducts
? the intercalated duct is long and has branches
? no striated duct
?main duct,lined by simple columnar
epithelium in which a few goblet cells
and endocrine cells can be seen
? The functions of exocrine portion
Secret abundant trypsinogen,
chymotrypsinogen,amylase,lipase,
sodium bicarbonate and trypsin inhibitor
Pancreas
Pancreas ( show centro-acinar cells
and intercalated ducts)
Endocrine portion (pancreatic islet):
? rounded clusters of cells embedded within
exocrine pancreatic tissue
? are divided into three kinds of cells,A,B,
and D cells
? fenestrated capillaries are among the
cells
Pancreas (show pancreatic islet)
Size number Distribution Function
A cells large 20% Peripheral glucagon
B cells small 75% center insulin
D cells 5% Among A and B cells somatostatin
Endocrine portion
Other cells
PP cells,pancreatic polypeptide
G cells,gastrin
A cells B cells
D cells
Liver
Liver lobule
Portal area
Hepatic plates
Sinusoid
Central vein
Interlobular arteries
Interlobular veins
Interlobular bile ducts
Functions of liver:
? bile secretion
? synthesize,protein,glycogen,cholesterin
? detoxification and inactivation
? defence
? hemopoiesis
Human liver
Pork liver
Liver lobule:
? hepatic plates,are composed of a single
layer of hepatocytes arranged in radial
? sinusoid,situated between the hepatic
plates,forming a complex network
? central vein,occupies the centre of the
liver lobule
Liver lobule
Hepatic
plates
Hepatic cords and liver sinusoids
Hepatocytes
? polyhedral in shape,eosinophilic cytoplasm,
one or two large rounded nuclei with one or 2
typical nucleoli
? EM,Mi,RER,SER,Golgi apparatus,
lysosomes,microbodies,inclusions
? Mitochondria
provide the energy for the hepatocytes
? Rough endoplasmic reticulum
synthesize some plasma proteins
? Golgi apparatus
participate in the formation of bile and
lipoprotein
? Smooth endoplasmic reticulum
? synthesize bile,triglyceride and LDL
? metabolism of the lipid,hormones and
cholerythrin
? inactivate steroid hormone
? biotransformation of some materials
? detoxification of noxious substances
? Lysosomes
? actively participate the metabolism of
hepatocyte and renewal of organelles
? play a role in metabolism and transport of
cholerythrin
? storage of iron
? Microbodies
detoxification,catalase and peroxidase;
reduce the hydrogen peroxide into H2O
? Inclusions
include glycogen,lipid droplets,pigment etc;
These contents vary according to physiologic
state of human body
Bile canaliculi
? between two adjacent hepatocytes
? the membrane of hepatocyte projects to
the lumen,forming many microvilli
? the cell membranes near the bile canaliculi
are firmly bound by junctional complexes
Bile canaliculi
Liver sinusoid
? spaces between the hepatic plates
? irregular in shape
? composed of only one discontinuous layer of
fenestrated endothelial cells,no diaphragm,
no basement membrane
? Kupffer cells are located within the sinusoid
cavities
Kuffer cells in liver sinusoid
Liver sinusoid
and space of
Disse
Space of Disse
? separates the endothelium from the
hepatocytes
? contains some reticular fibers and fat-storing
cells
Portal space:
? the connective tissue separating the lobules
? including
Interlobular arteries
Interlobular veins
Interlobular bile ducts
Portal spaces
Blood circulation:
portal V,interlobular V.
sinusoids
hepatic A,interlobular A.
central V.
sublobular V.
hepatic V.
（ functional vessel)
(nutrient vessel)
Blood vessels
of liver
(prepared Chinese
ink injection
through portal vein)
Discharge way of bile:
Bile canaliculi
Hering’s canals
Interlobular bile ducts
Hepatic duct
Common bile duct
Gallbladder
Cystic duct
duodenum
Gallbladder
? mucosa Simple columnar Epi.,no Goblet cells
Laminar propria,C.T.
? muscle layer,composed of an inner circular,
an outer longitudinal layers of smooth muscle
? adventitia,most are fibrosa,some are serosa
Gallbladder
