Chapter 17
Urinary System
1,Components
---kidney, produce urine
---ureters
---bladder -cavity organs,conduct,store and
---urethra remove the urine
---functions:
remove waste products of metabolism
regulate the homeostasis
secrete some bioactive factors- renin,
erythropoietin
*cavity organs:
mucosa:
/epi-transitional epi
/lamina propria
muscularis,SM
adventitia,CT
2,Kidney
---bean-shaped,10-12cm
in length,5-6cm in
width,3-4cm in
thickness
---hilum,BV,LV,N and
ureters enter or out
*renal pelvis,funnel-
shaped expension of
upper end of ureter
*calyx,branches of renal
pelvis
1) General structure:
---capsule,DCT
---cortex,dark stained
/medullary ray
/cortical labyrinth
---medulla,slight stained
/renal pyramid
/renal columns
/renal papillae:
-minor calyx
-major calyx
-pelvis
*renal lobe,one renal pyramid and its
bounding cortical tissue
*renal lobule,renal tissue including one
medullary ray and cortical tissue
surround it
According to function,
renal parenchyma is
mainly consists of
uriniferous tubules
---parenchyma:
/uriniferous tubules=
renal tubule+ collecting
tubules
/renal corpuscle
=glomerulus + renal
capsule(beginning part
of renal tubule)
/nephron=renal
corpuscle + renal tubule
---interstitium,CT,BV,N
2) Nephron,structural and functional unit,1,000,000
---renal corpuscle,cortical and juxtamedullary
nephron
/renal glomerulus:
/renal capsule
---renal tubule:
/proximal tubule:
-convoluted portion
-straight portion
/thin segment
/distal tubule:
-straight portion
-convoluted portion
① renal corpuscle,spherical,200um in D,
two poles,vascular pole and urinary pole
---glomerulus,afferent arterioles→capillary
network →efferent arterioles
*capillary network:
/endothelial cell,pore,70-90 nm,no
diaphragm
/basal lamina,330nm
*intraglomerular mesangium:
/mesangial cell:
-small,irregular,with processes
-small dark N
-EM,RER,Golgi,lysosome,phagocytic vesicles,
cytoskeleton-MF,MT,IF and secretory granules
-functions:
i,produce ground substance
ii,phagocytosis
iii,contract
iv,secrete renin and enzymes
/matrix:
-type IV collagen
-glycoprotein,sulphate chondritin,heparin and
dermatan
---renal capsule,two layers capsule –formed
by beginning part of renal tubule which is
enlarged and invaginated
/parietal layer,simple squamous epi.
/visceral layer,podocytes
/renel capsular cavity,the space between
two layers
cells with many processes
( primary and secondary processes-foot
processes)
Foot processes,interdigitated with each other
and embraced the capillaries,
slit pore:
-narrow intercellular space between foot
processes
-25 nm,with 4-6 nm diaphragm-slit
membrane
*podocyte:
---function,produce filtrate by filtration
* filtration barrier or membrane,the structure
for filtration is called filtration barrier or
membrane,including:
fenestrated endothelial cell,negative ions
basal lamina,type IV collagen,proteoglycan,
laminin-negative ions (sulphate heparin)
slit membrane-nephrin(size selective filter:
negative ions
② renal tubule:
a,proximal tubule,50-60um in D,14 mm long
---structure
LM,EM:
pyramidal cuboidal
eosinophilic
round N
brush-liked border - microvilli(apical canaliculi)
longitudinal striation- plasma membrane infolding
no clear boundary - lateral extension
(rich in Na+ K+ ATPase)
Proximal tubule
---Function:
i,reabsorption,
-85% Na+ ions and water
-All of glucose,aminoacid,polypeptide,
proteins and vitamin
-50% bicorbonated salt and sulphate salt
ii,secrete H+,NH3,hippuric acid and creatinine
b,thin segment:
/10-15 um,simple squamous epi,
/facilitate the passage of water and ions
/reabsorb Na+ and Cl- and 5% water
c,distal tubule:
---structure:
LM,EM:
cuboidal
slight-stained
round N
no brush-liked border – less microvilli
well-developed
longitudinal striation – plasma membrane infolding
Distal tubule Plasma membrane infolding
---function:
i,reabsorption of 8% water,Na+ ions
ii,excretion of K+,H+,NH3
iii,regulated by aldosterone(adrenal
gland) and antidiuretic hormone
(vasopressin) (pituitary gland)
3) collecting tubule:
arched collecting tubules
cortical collection tubules
medullary collection tubules
-simple cuboidal epi,to simple columnar epi.
-slight –stained
-have clear boundary
-reabsorb 4% water
4) juxtaglomerular complex
极周细胞
a,juxtaglomerular cell:
---a groups of modified SM cell of afferent arterioles
---structure:
-larger,cuboidal in shaped,with round N
-contain secretory granules
---function:
i.secrete renin→adrenal gland→aldosterone→blood pressure↑
↑
angiotensinogen→angiotensin I→angiotensin II→contraction of
SM of BV
ii,secrete erythropoietin to promote erythropoiesis
b,macula densa
---a group of cells derived from epi,of distal
tubule
---cell becomes taller,narrow,with round N
apical part arranged
---cells have processes connecting with other
cells
---function,chemoreceptors- feel the Na+ ions
concentration
c,extraglomerular mesangial cell(polar
cushion cell)
---similar to intraglomerular mesangial cell
---transfer the information
d,peripolar cell
---structure:
EM,-microvilli
-junctional complexes
-RER,Golgi,and granules
---function,regulate the reabsorption and
secretion of renal tubule
5) renal interstitial,CT
---fibers,type I,III,IV collagen
---matrix
---cell:
fibroblast
macrophage
lipid-laden interstitial cell:
-stellate cell with processes
-osmiophilic lipid droplets:
-function:
i,involve in formation of F and matrix
ii,secret prostaglandin
6) Blood supply to the
kidney
i,Very large blood flow
(1.2L/min)
ii,To form cap.two times
iii,Glomerular cap,have
a high blood
pressure
iv,Form vasa recta loop
near medullary loop
v,More larger blood flow
in renal cortex
Interlobar arteries → Arcuate arteries →Interlobular arteries →Capsular cap.
↑ ↓ ↓
Renal artery Afferent arterioles Afferent arterioles
↓ ↓
Juxtamedullary nephron Cortical nephron
glomerulus glomerulus
↓ ↓
Efferent arterioles Efferent arterioles
↓ ↓
Vasa recta(artery and vein)← Capillary network Capillary network
↓ ↓ ↓
Renal vein←Interlobar vein← Arcuate vein ← Interlobular vein ← Stellate vein
Urinary System
1,Components
---kidney, produce urine
---ureters
---bladder -cavity organs,conduct,store and
---urethra remove the urine
---functions:
remove waste products of metabolism
regulate the homeostasis
secrete some bioactive factors- renin,
erythropoietin
*cavity organs:
mucosa:
/epi-transitional epi
/lamina propria
muscularis,SM
adventitia,CT
2,Kidney
---bean-shaped,10-12cm
in length,5-6cm in
width,3-4cm in
thickness
---hilum,BV,LV,N and
ureters enter or out
*renal pelvis,funnel-
shaped expension of
upper end of ureter
*calyx,branches of renal
pelvis
1) General structure:
---capsule,DCT
---cortex,dark stained
/medullary ray
/cortical labyrinth
---medulla,slight stained
/renal pyramid
/renal columns
/renal papillae:
-minor calyx
-major calyx
-pelvis
*renal lobe,one renal pyramid and its
bounding cortical tissue
*renal lobule,renal tissue including one
medullary ray and cortical tissue
surround it
According to function,
renal parenchyma is
mainly consists of
uriniferous tubules
---parenchyma:
/uriniferous tubules=
renal tubule+ collecting
tubules
/renal corpuscle
=glomerulus + renal
capsule(beginning part
of renal tubule)
/nephron=renal
corpuscle + renal tubule
---interstitium,CT,BV,N
2) Nephron,structural and functional unit,1,000,000
---renal corpuscle,cortical and juxtamedullary
nephron
/renal glomerulus:
/renal capsule
---renal tubule:
/proximal tubule:
-convoluted portion
-straight portion
/thin segment
/distal tubule:
-straight portion
-convoluted portion
① renal corpuscle,spherical,200um in D,
two poles,vascular pole and urinary pole
---glomerulus,afferent arterioles→capillary
network →efferent arterioles
*capillary network:
/endothelial cell,pore,70-90 nm,no
diaphragm
/basal lamina,330nm
*intraglomerular mesangium:
/mesangial cell:
-small,irregular,with processes
-small dark N
-EM,RER,Golgi,lysosome,phagocytic vesicles,
cytoskeleton-MF,MT,IF and secretory granules
-functions:
i,produce ground substance
ii,phagocytosis
iii,contract
iv,secrete renin and enzymes
/matrix:
-type IV collagen
-glycoprotein,sulphate chondritin,heparin and
dermatan
---renal capsule,two layers capsule –formed
by beginning part of renal tubule which is
enlarged and invaginated
/parietal layer,simple squamous epi.
/visceral layer,podocytes
/renel capsular cavity,the space between
two layers
cells with many processes
( primary and secondary processes-foot
processes)
Foot processes,interdigitated with each other
and embraced the capillaries,
slit pore:
-narrow intercellular space between foot
processes
-25 nm,with 4-6 nm diaphragm-slit
membrane
*podocyte:
---function,produce filtrate by filtration
* filtration barrier or membrane,the structure
for filtration is called filtration barrier or
membrane,including:
fenestrated endothelial cell,negative ions
basal lamina,type IV collagen,proteoglycan,
laminin-negative ions (sulphate heparin)
slit membrane-nephrin(size selective filter:
negative ions
② renal tubule:
a,proximal tubule,50-60um in D,14 mm long
---structure
LM,EM:
pyramidal cuboidal
eosinophilic
round N
brush-liked border - microvilli(apical canaliculi)
longitudinal striation- plasma membrane infolding
no clear boundary - lateral extension
(rich in Na+ K+ ATPase)
Proximal tubule
---Function:
i,reabsorption,
-85% Na+ ions and water
-All of glucose,aminoacid,polypeptide,
proteins and vitamin
-50% bicorbonated salt and sulphate salt
ii,secrete H+,NH3,hippuric acid and creatinine
b,thin segment:
/10-15 um,simple squamous epi,
/facilitate the passage of water and ions
/reabsorb Na+ and Cl- and 5% water
c,distal tubule:
---structure:
LM,EM:
cuboidal
slight-stained
round N
no brush-liked border – less microvilli
well-developed
longitudinal striation – plasma membrane infolding
Distal tubule Plasma membrane infolding
---function:
i,reabsorption of 8% water,Na+ ions
ii,excretion of K+,H+,NH3
iii,regulated by aldosterone(adrenal
gland) and antidiuretic hormone
(vasopressin) (pituitary gland)
3) collecting tubule:
arched collecting tubules
cortical collection tubules
medullary collection tubules
-simple cuboidal epi,to simple columnar epi.
-slight –stained
-have clear boundary
-reabsorb 4% water
4) juxtaglomerular complex
极周细胞
a,juxtaglomerular cell:
---a groups of modified SM cell of afferent arterioles
---structure:
-larger,cuboidal in shaped,with round N
-contain secretory granules
---function:
i.secrete renin→adrenal gland→aldosterone→blood pressure↑
↑
angiotensinogen→angiotensin I→angiotensin II→contraction of
SM of BV
ii,secrete erythropoietin to promote erythropoiesis
b,macula densa
---a group of cells derived from epi,of distal
tubule
---cell becomes taller,narrow,with round N
apical part arranged
---cells have processes connecting with other
cells
---function,chemoreceptors- feel the Na+ ions
concentration
c,extraglomerular mesangial cell(polar
cushion cell)
---similar to intraglomerular mesangial cell
---transfer the information
d,peripolar cell
---structure:
EM,-microvilli
-junctional complexes
-RER,Golgi,and granules
---function,regulate the reabsorption and
secretion of renal tubule
5) renal interstitial,CT
---fibers,type I,III,IV collagen
---matrix
---cell:
fibroblast
macrophage
lipid-laden interstitial cell:
-stellate cell with processes
-osmiophilic lipid droplets:
-function:
i,involve in formation of F and matrix
ii,secret prostaglandin
6) Blood supply to the
kidney
i,Very large blood flow
(1.2L/min)
ii,To form cap.two times
iii,Glomerular cap,have
a high blood
pressure
iv,Form vasa recta loop
near medullary loop
v,More larger blood flow
in renal cortex
Interlobar arteries → Arcuate arteries →Interlobular arteries →Capsular cap.
↑ ↓ ↓
Renal artery Afferent arterioles Afferent arterioles
↓ ↓
Juxtamedullary nephron Cortical nephron
glomerulus glomerulus
↓ ↓
Efferent arterioles Efferent arterioles
↓ ↓
Vasa recta(artery and vein)← Capillary network Capillary network
↓ ↓ ↓
Renal vein←Interlobar vein← Arcuate vein ← Interlobular vein ← Stellate vein
