Chapter 13
Digestive tract
---Digestive system:
Digestivetract
Digestivegland
1,Components of digestive tract
---oral cavity
---pharynx
---esophagus
---stomach
---small intestine
---large intestine
2,General plan of digestive tract
---Except for oral cavity and pharynx,all other
organs share a similar histological plan
1) mucosa
---epithelium:
stratified squamous epi.,protecting
simple columnar epi,,digestion and
absorption
---lamina propria,LCT-compact CT,contain
more cells and fiber
BV,LV-capillaries
Lymphoid T
glands,structures formed by invagination of
epi,into lamina propria
---muscularis mucosa,a thin layer of SM
2) submucosa,more dense CT
small artery and vein,LV
glands (esophagus and duodenum)
submucosa N plexus:
-multipolar N
-unmyelinated NF
-function,regulate the contract of SM and
secreting of gland
*Plica,projection of mucosa and submucosa
3) muscularis externa
smooth muscle
skeletalmuscle
inner circularand outer longitudinal
*Nerve plexus,regulate the movement of
M
4) adventitia,CT
serosa:CT + mesothelium
fibrosa:LCT
3,Esophagus
1) mucosa:
epithelium:stratifiedsquamousepi.
laminapropria,compact CT
muscularis mucosa,longitudinal
arranged SM
2) submucosa:
LCT
esophagealgland:mucous gland
3) muscularis:
inner circular and outer longitudinal
upper 1/3,skeletal muscle
middle 1/3,mixed of skeletal M and smooth
muscle
lower 1/3,smooth muscle
4) adventitia,fibrosa
4,Stomach
---dilated part
---store food temporarily
---digest protein primarily
---absorbpart of water and Ions
1) Mucosa:
---plica-longitudinal
---shallowditch- gastric area(2-6mm)
---gastric pit- small depressions
① epithelium,simple
columnar epi
surface mucous cell:
-tall columnar
-N ovoid,basally-located
-mucinogen granule
-tight junction
-high HCO3- undissolved
mucus
less endocrine cell
② lamina propria,CT contains fibroblast,
LC,plasma cell,mast cell and
eosinophil,SM
gastric gland(fundic gland)-oxyntic
gland
cardiacgland,mucous gland
pyloric gland,mucous gland
* Fundic gland
-long,branch tube liked
gland:
/neck,body and basa
-five types of cells can be
seen
a,chief cell or zymogenic
cell
---structure:
LM:
columnar
Round,basally-located
Nucleus
cytoplasm:
/basal-basophilic
/apical-zymogen granules
EM,RER,Golgi apparatus
---function,secret
pepsinogen
b,parietal cell or oxyntic cell
---structure:
LM:
large,pyramidal or spherical
round centrally-located
nucleus
eosinophilic cytoplasm
EM:
intracellular secretory
canaliculus-invaginations
tubulovesicular system
mitochondria
---function:
i,secret hydrochloric acid (HCl)
-synthesis processes of HCl,in intracellular
secretory canaliculus
H+ K+ -ATP pump,get H+ from cell
Cl- channel,get Cl- from blood
H+ +Cl-→HCl(intracellular secretort canaliculi)
-function of HCl:
HCl
↓
pepsinogen→pepsin
kill the bacterium
ii,secret intrinsic factor- glycoprotein +
VB12→absorptionof VB12
c,mucous neck cell
less,neck part
columnar
flattened,basally-located N
pale stain in HE stain
d,stem cell,undifferentiatedcell
e,endocrine cell
ECL cell,secreting histamine,promote
secretion of parietal cell
D cell,secreting somatostatin,inhibit the
secretion of parietal cell
* cardiac gland and pyloric
gland,mucous gland,contain
G cell,which secretes gastrin,
to promote the secreting of
parietal cell
* Mucous-HCO3barrier:
0.25-0.5mm thick mucous
HCl PH,0.9-1.5
H+ + HCO3- → H2CO3 →H2O +
CO2
↑
bicarbonatase
③ Muscularis mucosa,inner circular and
outer longitudinal arranged SM
2) submucosa,CT with BV,LV,N and fat
cell
3) muscularis,thicker
inner oblique
middle circular
outer longitudinal
4) advantitia,serosa
5,Small intestine
---duodenum
---jejunum
---ileum
1) Mucosa
---circular plica
---intestinal villus
---small intestinal
gland
① epithelium:
---absorptive cell:
microvilli,striated-border
-1-1.4um long,80nm in D,
2000-3000
-enlarge the surface area
to 30 times
cell coat:
-0.1-0.5um
-enzymes,trypsinogen,
amylase - glucose and
protein
enzymes-adipose
SER
---goblet cell
---endocrine cell:
I cell,secreting cholecystokinin-
pancreozymin
S cell:secreting secretin
② lamina propria,CT (LC,
macrophage,plasma cell
and eosinophil and mast
cell)
a,villus,is the projection
of epithelium and lamina
propria
epithelium,absorptive
cell,goblet cell and
endocrine cell
lamina propria,CT with
central lacteal,
fenestrated cap,and SM
b,small intestinal gland,is the
invaginationof epi.into propria
absorptivecell
goblet cell
endocrine cell
stem cell
Peneth cell
Peneth cell:
LM:
-pyramidal,basally-
located,in groups
-apical,acidophilic G-
contain
defensin(cryptdin),
Lysozyme
EM:
-protein-secreting cell
feature
Function,related to
immune function
③ muscularis mucosa,SM inner circular
and outer longitudinal
2) submucosa:CT
Large BV and LV
duodenal gland,mucous gland-
secreting epidermal growth factor,
promote the epithelial cell proliferation
of small intestine
3) muscularis,SM,inner circular and
outer longitudinal
4) adventitia,serosa and less fibrosa
6,Large intestine
---absorbwater and ions
---structurefeature:
a,no villusand no circularplica
b,well-developedlarge intestinalgland
c,contain more goblet cells
d,taeniae coli:longitudinalbunds
bag coli
Digestive tract
---Digestive system:
Digestivetract
Digestivegland
1,Components of digestive tract
---oral cavity
---pharynx
---esophagus
---stomach
---small intestine
---large intestine
2,General plan of digestive tract
---Except for oral cavity and pharynx,all other
organs share a similar histological plan
1) mucosa
---epithelium:
stratified squamous epi.,protecting
simple columnar epi,,digestion and
absorption
---lamina propria,LCT-compact CT,contain
more cells and fiber
BV,LV-capillaries
Lymphoid T
glands,structures formed by invagination of
epi,into lamina propria
---muscularis mucosa,a thin layer of SM
2) submucosa,more dense CT
small artery and vein,LV
glands (esophagus and duodenum)
submucosa N plexus:
-multipolar N
-unmyelinated NF
-function,regulate the contract of SM and
secreting of gland
*Plica,projection of mucosa and submucosa
3) muscularis externa
smooth muscle
skeletalmuscle
inner circularand outer longitudinal
*Nerve plexus,regulate the movement of
M
4) adventitia,CT
serosa:CT + mesothelium
fibrosa:LCT
3,Esophagus
1) mucosa:
epithelium:stratifiedsquamousepi.
laminapropria,compact CT
muscularis mucosa,longitudinal
arranged SM
2) submucosa:
LCT
esophagealgland:mucous gland
3) muscularis:
inner circular and outer longitudinal
upper 1/3,skeletal muscle
middle 1/3,mixed of skeletal M and smooth
muscle
lower 1/3,smooth muscle
4) adventitia,fibrosa
4,Stomach
---dilated part
---store food temporarily
---digest protein primarily
---absorbpart of water and Ions
1) Mucosa:
---plica-longitudinal
---shallowditch- gastric area(2-6mm)
---gastric pit- small depressions
① epithelium,simple
columnar epi
surface mucous cell:
-tall columnar
-N ovoid,basally-located
-mucinogen granule
-tight junction
-high HCO3- undissolved
mucus
less endocrine cell
② lamina propria,CT contains fibroblast,
LC,plasma cell,mast cell and
eosinophil,SM
gastric gland(fundic gland)-oxyntic
gland
cardiacgland,mucous gland
pyloric gland,mucous gland
* Fundic gland
-long,branch tube liked
gland:
/neck,body and basa
-five types of cells can be
seen
a,chief cell or zymogenic
cell
---structure:
LM:
columnar
Round,basally-located
Nucleus
cytoplasm:
/basal-basophilic
/apical-zymogen granules
EM,RER,Golgi apparatus
---function,secret
pepsinogen
b,parietal cell or oxyntic cell
---structure:
LM:
large,pyramidal or spherical
round centrally-located
nucleus
eosinophilic cytoplasm
EM:
intracellular secretory
canaliculus-invaginations
tubulovesicular system
mitochondria
---function:
i,secret hydrochloric acid (HCl)
-synthesis processes of HCl,in intracellular
secretory canaliculus
H+ K+ -ATP pump,get H+ from cell
Cl- channel,get Cl- from blood
H+ +Cl-→HCl(intracellular secretort canaliculi)
-function of HCl:
HCl
↓
pepsinogen→pepsin
kill the bacterium
ii,secret intrinsic factor- glycoprotein +
VB12→absorptionof VB12
c,mucous neck cell
less,neck part
columnar
flattened,basally-located N
pale stain in HE stain
d,stem cell,undifferentiatedcell
e,endocrine cell
ECL cell,secreting histamine,promote
secretion of parietal cell
D cell,secreting somatostatin,inhibit the
secretion of parietal cell
* cardiac gland and pyloric
gland,mucous gland,contain
G cell,which secretes gastrin,
to promote the secreting of
parietal cell
* Mucous-HCO3barrier:
0.25-0.5mm thick mucous
HCl PH,0.9-1.5
H+ + HCO3- → H2CO3 →H2O +
CO2
↑
bicarbonatase
③ Muscularis mucosa,inner circular and
outer longitudinal arranged SM
2) submucosa,CT with BV,LV,N and fat
cell
3) muscularis,thicker
inner oblique
middle circular
outer longitudinal
4) advantitia,serosa
5,Small intestine
---duodenum
---jejunum
---ileum
1) Mucosa
---circular plica
---intestinal villus
---small intestinal
gland
① epithelium:
---absorptive cell:
microvilli,striated-border
-1-1.4um long,80nm in D,
2000-3000
-enlarge the surface area
to 30 times
cell coat:
-0.1-0.5um
-enzymes,trypsinogen,
amylase - glucose and
protein
enzymes-adipose
SER
---goblet cell
---endocrine cell:
I cell,secreting cholecystokinin-
pancreozymin
S cell:secreting secretin
② lamina propria,CT (LC,
macrophage,plasma cell
and eosinophil and mast
cell)
a,villus,is the projection
of epithelium and lamina
propria
epithelium,absorptive
cell,goblet cell and
endocrine cell
lamina propria,CT with
central lacteal,
fenestrated cap,and SM
b,small intestinal gland,is the
invaginationof epi.into propria
absorptivecell
goblet cell
endocrine cell
stem cell
Peneth cell
Peneth cell:
LM:
-pyramidal,basally-
located,in groups
-apical,acidophilic G-
contain
defensin(cryptdin),
Lysozyme
EM:
-protein-secreting cell
feature
Function,related to
immune function
③ muscularis mucosa,SM inner circular
and outer longitudinal
2) submucosa:CT
Large BV and LV
duodenal gland,mucous gland-
secreting epidermal growth factor,
promote the epithelial cell proliferation
of small intestine
3) muscularis,SM,inner circular and
outer longitudinal
4) adventitia,serosa and less fibrosa
6,Large intestine
---absorbwater and ions
---structurefeature:
a,no villusand no circularplica
b,well-developedlarge intestinalgland
c,contain more goblet cells
d,taeniae coli:longitudinalbunds
bag coli
