Principles of Anatomy
and Physiology
Thirteenth Edition
Gerard J. Tortora • Bryan H. Derrickson
Chapter 26
The Urinary System
Copyright © 2012 by John Wiley & Sons, Inc.
Diaphragm
Esophagus
RIGHT KIDNEY
Left adrenal
(suprarenal) gland
Left renal vein
Right renal artery
RIGHT URETER
LEFT KIDNEY
Abdominal aorta
Inferior vena cava
URINARY
BLADDER
LEFT URETER
Left ovary
URETHRA
Rectum
Uterus
Adrenal (suprarenal) gland
Inferior vena cava
Suprarenal arteries
Renal artery
Renal vein
KIDNEY
URETER
LATERAL
MEDIAL
(b) Anterior view
Transverse
plane
ANTERIOR
Large intestine
Stomach
Liver
Pancreas
Renal artery
and vein
View
Layers
Inferior vena cava
Peritoneum
Abdominal
aorta
Body of
L2
RENAL
HILUM
RENAL FASCIA
LEFT KIDNEY
ADIPOSE CAPSULE
RENAL CAPSULE
Spleen
Rib
RIGHT KIDNEY
POSTERIOR
(a) Inferior view of transverse section of abdomen (L2)
Quadratus
lumborum
muscle
SUPERIOR
Lung
Parasagittal
plane
Liver
Diaphragm
Adrenal (suprarenal)
gland
Twelfth rib
Peritoneum
Right kidney
ADIPOSE CAPSULE
RENAL CAPSULE
Quadratus lumborum
muscle
Large intestine
Hip bone
POSTERIOR
ANTERIOR
(b) Parasagittal section through right kidney
Layers
RENAL FASCIA
PATH OF URINE DRAINAGE:
Nephron
Collecting duct
Renal
hilum
Minor calyx
Renal cortex
Renal artery
Renal medulla
Renal vein
Major calyx
Renal pelvis
Renal column
Renal pyramid
in renal medulla
Renal papilla
Ureter
Renal capsule
Urinary bladder
(a) Anterior view of dissection of right kidney
SUPERIOR
Renal capsule
Renal cortex
Minor calyx
Renal artery
Renal vein
Major calyx
Renal pelvis
Ureter
LATERAL
MEDIAL
(b) Posterior view of dissection of left kidney
Glomerulus
Frontal plane
Afferent
arteriole
Peritubular
capillary
Efferent
arteriole
Interlobular
vein
Vasa recta
Blood supply of nephron
Interlobular artery
Renal capsule
Arcuate artery
Interlobar artery
Segmental artery
Renal cortex
Renal artery
Renal vein
Interlobar vein
Renal pyramid
in renal medulla
Arcuate vein
Interlobular vein
(a) Frontal section of right kidney
Renal artery
Segmental arteries
Interlobar arteries
Arcuate arteries
Interlobular arteries
Afferent arterioles
Glomerular capillaries
Efferent arterioles
Peritubular capillaries
Interlobular veins
Arcuate veins
Interlobar veins
(b) Path of blood flow
Renal vein
Renal capsule
Renal corpuscle:
Proximal convoluted tubule
Glomerular (Bowman's) capsule
Glomerulus
Peritubular capillary
Efferent arteriole
Distal convoluted tubule
Afferent arteriole
Interlobular artery
Interlobular vein
Arcuate vein
Renal cortex
Renal cortex
Renal medulla
Renal medulla
Arcuate artery
Corticomedullary junction
Renal papilla
Loop of Henle:
Minor calyx
Descending limb
FLOW OF FLUID THROUGH A
CORTICAL NEPHRON
Ascending limb
Kidney
Collecting duct
Glomerular (Bowman's) capsule
Proximal convoluted tubule
Papillary duct
Descending limb of the
loop of Henle
Renal papilla
Ascending limb of the
loop of Henle
Distal convoluted tubule
(drains into collecting duct)
Minor calyx
Urine
(a) Cortical nephron and vascular supply
Renal capsule
Distal convoluted tubule
Renal corpuscle:
Proximal convoluted tubule
Glomerular (Bowman's) capsule
Glomerulus
Peritubular capillary
Afferent arteriole
Efferent arteriole
Interlobular artery
Renal cortex
Interlobular vein
Renal cortex
Renal medulla
Arcuate vein
Renal medulla
Renal papilla
Arcuate artery
Peritubular
capillary
Minor calyx
Corticomedullary junction
Collecting duct
FLOW OF FLUID THROUGH A
JUXTAMEDULLARY NEPHRON
Loop of Henle:
Glomerular (Bowman's) capsule
Proximal convoluted tubule
Descending limb of the
loop of Henle
Kidney
Descending limb
Vasa
recta
Thick ascending limb
Thin ascending limb
Papillary duct
Thin ascending limb of the
loop of Henle
Renal papilla
Thick ascending limb of the
loop of Henle
Minor calyx
Distal convoluted tubule
(drains into collecting duct)
Urine
(b) Juxtamedullary nephron and vascular supply
Microvilli
Mitochondrion
Apical surface
Proximal convoluted tubule (PCT)
Loop of Henle: descending limb and
thin ascending limb
Loop of Henle: thick ascending limb
Most of distal convoluted tubule
(DCT)
Last part of DCT and all of
collecting duct (CD)
Intercalated
cell
Principal
cell
Renal corpuscle
(external view)
Parietal layer of glomerular
(Bowman’s) capsule
Afferent arteriole
Mesangial cell
Juxtaglomerular cell
Capsular space
Macula densa
Ascending limb
of loop of Henle
Proximal
convoluted
tubule
Mesangial cell
Efferent arteriole
Podocyte of visceral layer of
glomerular (Bowman’s) capsule
Endothelium of
glomerulus
(a) Renal corpuscle (internal view)
Pedicel
Glomerular capsule:
Glomerulus
Parietal layer
Podocytes of visceral
layer of glomerular
capsule
Visceral layer
Afferent arteriole
Juxtaglomerular cell
Capsular
space
Ascending limb of loop
of Henle
Macula densa cell
Simple squamous
epithelial cells
Efferent arteriole
Proximal convoluted
tubule
LM 1380x
(b) Renal corpuscle
Renal corpuscle
Afferent
arteriole
Glomerular filtration (filtration
of blood plasma by glomerulus)
Glomerular
capsule
Renal tubule and collecting duct
Glomerulus
Glomerular filtrate
in renal tubule
1
2 Tubular reabsorption
from glomerular
filtrate into blood
Efferent
arteriole
Peritubular capillaries
3 Tubular secretion
Urine
(contains
excreted
substances)
from blood into
glomerular filtrate
Blood
(contains
reabsorbed
substances)
Podocyte of visceral
layer of glomerular
(Bowman’s) capsule
Filtration slit
Pedicel
1 Fenestration (pore) of glomerular
endothelial cell: prevents filtration of blood
cells but allows all components of blood
plasma to pass through
2 Basal lamina of glomerulus:
prevents filtration of larger proteins
3 Slit membrane between pedicels:
prevents filtration of medium-sized proteins
(a) Details of filtration membrane
Pedicel of podocyte
Filtration slit
Basal
lamina
Lumen of
glomerulus
Fenestration (pore) of
glomerular endothelial cell
(b) Filtration membrane
TEM 78,000x
1 GLOMERULAR BLOOD
HYDROSTATIC PRESSURE
(GBHP) = 55 mmHg
2 CAPSULAR HYDROSTATIC
PRESSURE (CHP) = 15 mmHg
3 BLOOD COLLOID
OSMOTIC PRESSURE
(BCOP) = 30 mmHg
Afferent arteriole
Proximal convoluted tubule
Efferent arteriole
Glomerular
(Bowman's)
capsule
Capsular
space
NET FILTRATION PRESSURE (NFP)
= GBHP – CHP – BCOP
= 55 mmHg – 15 mmHg – 30 mmHg
= 10 mmHg
Some stimulus
disrupts homeostasis
by
Increasing
Glomerular filtration
rate (GFR)
Receptors
Macula densa
cells of JGA
detect increased
delivery of Na+,
Cl –, and water
Input
Control center
Juxtaglomerular
apparatus
Return to homeostasis
when response brings
GFR back to normal
Decreased secretion
of nitric oxide
Output
Effectors
Afferent arteriole
constricts, which
decreases blood
flow through
glomerulus
Decrease in GFR
Tubule
cell
Fluid in
tubule
lumen
Na+
Peritubular
capillary
Na+
Na+
Paracellular
reabsorption
ATP
Na+
Na+
ADP
Na+
Na+
Key:
Transcellular
reabsorption
Diffusion
Basolateral
membrane
Apical
membrane
Tight junction
Interstitial
fluid
Active transport
Sodium–potassium pump
(Na+/K+ ATPase)
Fluid in
tubule
lumen
Proximal
convoluted
tubule cell
ATP
2 Na+
Na+
Peritubular
capillary
Na+
Na+
ADP
Key:
Na+–glucose symporter
Glucose
Glucose
Glucose
Glucose facilitated diffusion transporter
Diffusion
Tight junction
Brush border (microvilli)
Interstitial
fluid
Sodium–potassium pump
Fluid in
tubule
lumen
Proximal
convoluted
tubule cell
Na+
Na+
H+
Peritubular
capillary
HCO3–
H+
ATP
HCO3–
Na+
HCO3–
Na+
H2CO3
ADP
Metabolic reactions
CA
CO2
Key:
Na+/H+ antiporter
Na+
H2O
CO2
CO2
HCO3– facilitated diffusion transporter
Diffusion
Interstitial
fluid
(a) Na+ reabsorption and H+ secretion
Sodium–potassium pump
Fluid in
tubule
lumen
Peritubular
capillary
Na+
HCO3–
Na+
Na+
Key:
H+
H+
CA
ADP
HCO3–
H2CO3
H2CO3
CO2
H2O
ATP
H2O
CO2
HCO3–
Na+/H+ antiporter
HCO3– facilitated diffusion transporter
Diffusion
Sodium–potassium pump
(b) HCO3– reabsorption
Fluid in
tubule
lumen
Cl–
K+
Ca2+
Mg2+
Urea
H2O
Proximal
convoluted
tubule cell
Diffusion
Osmosis
Peritubular
capillary
Cl–
K+
Ca2+
Mg2+
Urea
H2O
Fluid in
tubule
lumen
Vasa recta
Thick ascending
limb cell
Na+
ATP
Na+
ADP
Na+
2Cl–
K+
Cations:
Na+
K+
Ca2+
Mg2+
Na+
Na+
2Cl–
2Cl–
2Cl–
K+
Cations
Key:
Na+–K+–2Cl– symporter
Apical membrane
(impermeable to
water)
Interstitial fluid is
more negative than
fluid in tubule lumen
Leakage channels
Sodium–potassium pump
Diffusion
Fluid in
tubule
lumen
Principal
cell
Peritubular
capillary
K+
K+
ATP
Na+
Na+
Na+
ADP
Na+
K+
Key:
Diffusion
Interstitial
fluid
Leakage channels
Sodium–potassium pump
Some stimulus
disrupts
homeostasis by
Increasing
Osmolarity of plasma
and interstitial fluid
Receptors
Osmoreceptors
in hypothalamus
Nerve impulses
Input
Control center
Hypothalamus and
posterior pituitary
Return to homeostasis
when response brings
plasma osmolarity
back to normal
ADH
Increased release
of ADH
Output
Effectors
H2O
Principal cells
become more permeable
to water, which
increases facultative
water reabsorption
Decrease in
plasma osmolarity
Afferent
arteriole
Glomerular (Bowman's) capsule
Glomerulus
Distal convoluted
tubule
Efferent
arteriole
100
300
Proximal
convoluted
tubule
90
300 300
350 350
150
Interstitial
fluid in
renal
cortex
350
Collecting
duct
550 550
750 750
350
550
550
80
Interstitial
fluid in
renal
medulla
750
70
900
Loop of
Henle
65
65
Papillary
duct
Dilute
urine
Vasa
recta
Loop of
Henle
Juxtamedullary
nephron and its blood
supply together
Glomerular (Bowman’s) capsule
Afferent
arteriole
Distal convoluted
tubule
Efferent
arteriole
300
400
600
Osmotic
gradient
800
1000
Proximal
convoluted
tubule
Interstitial fluid
in renal medulla
200
HO
H2O 2
300
H2O
Interstitial
fluid in
renal cortex
Flow of tubular fluid
320
300
Collecting duct
300
H2O
300
320
100
Na+Cl–
380
H2O
200
1
580
Symporters in thick
ascending limb
cause buildup of
Na+ and Cl– in
780
renal medulla
H2O
2
Countercurrent flow
1200 through loop of
Henle establishes
osmotic gradient
H2O
Na+Cl–
Blood flow
Presence of Na+–K+–2Cl–
symporters
Glomerulus
400
H2O
400
H2O
H2O
3 Principal cells in
collecting duct
reabsorb more
water when ADH
is present
400
500
Na+Cl–
600
H2O
Na+Cl–
600
H 2O
600
Urea 800
1000
800
980
H2O
1200
Loop of Henle
(a) Reabsorption of Na+, Cl–, and water in
long-loop juxtamedullary nephron
1200
1200
4 Urea recycling
700
800
causes buildup of
urea in renal
medulla
H2O 900
H2O
Na+Cl–
1000
Na+Cl–
1100
Papillary duct
1200
Concentrated urine
(b) Recycling of salts and urea in vasa recta
RENAL CORPUSCLE
PROXIMAL CONVOLUTED TUBULE
Glomerular filtration rate: 105–125
mL/min of fluid that is isotonic to
blood
Reabsorption (into blood) of filtered:
Water
65% (osmosis)
Na+
65% (sodium–potassium pumps, symporters,
antiporters)
K+
65% (diffusion)
Glucose
100% (symporters and facilitated diffusion)
Amino acids
100% (symporters and facilitated diffusion)
Cl–
50% (diffusion)
HCO3–
80–90% (facilitated diffusion)
Urea
50% (diffusion)
Ca2+, Mg2+
variable (diffusion)
Filtered substances: water and all solutes
present in blood (except proteins)
including ions, glucose, amino acids,
creatinine, uric acid
EARLY DISTAL CONVOLUTED TUBULE
Reabsorption (into blood) of:
Secretion (into urine) of:
H+
variable (antiporters)
NH4+
variable, increases in acidosis (antiporters)
Urea
variable (diffusion)
Creatinine
small amount
Water
10–15% (osmosis)
Na+
5% (symporters)
CI–
5% (symporters)
Ca2+
variable (stimulated by parathyroid
hormone)
LATE DISTAL CONVOLUTED TUBULE AND
COLLECTING DUCT
Reabsorption (into blood) of:
At end of PCT, tubular fluid is still isotonic to blood (300 mOsm/liter).
LOOP OF HENLE
Water
5–9% (insertion of water channels
stimulated by ADH)
Na+
1–4% (sodium–potassium pumps and
sodium channels stimulated by
aldosterone)
HCO3–
variable amount, depends on H+
secretion (antiporters)
Urea
variable (recycling to loop of Henle)
Reabsorption (into blood) of:
Water
15% (osmosis in descending limb)
Na+
20–30% (symporters in ascending limb)
K+
20–30% (symporters in ascending limb)
CI–
35% (symporters in ascending limb)
HCO3–
10–20% (facilitated diffusion)
Ca2+, Mg2+
variable (diffusion)
Secretion (into urine) of:
Urea
variable (recycling from collecting duct)
At end of loop of Henle, tubular fluid is hypotonic (100–150 mOsm/liter).
Urine
Secretion (into urine) of:
K+
variable amount to adjust for dietary
intake (leakage channels)
H+
variable amounts to maintain acid–base
homeostasis (H+ pumps)
Tubular fluid leaving the collecting duct is dilute
when ADH level is low and
concentrated when ADH level is high.
Ureters
Ureteral openings
Frontal
plane
Rugae of mucosa
Peritoneum
Detrusor
muscle
Trigone
Internal urethral orifice
Internal urethral sphincter
(involuntary)
Urethra
External urethral sphincter in
deep muscles of perineum
(voluntary)
Hip bone
(pubis)
External urethral orifice
Anterior view of frontal section
Sagittal
plane
Uterus
Urinary bladder
Pubic symphysis
Rectum
Urethra
Vagina
External urethral
orifice
(a) Sagittal section, female
Sagittal
plane
Urinary bladder
Rectum
Pubic symphysis
Prostatic urethra
Prostate
Deep muscles of
perineum
Membranous
urethra
Penis
Spongy urethra
Testis
Scrotum
(b) Sagittal section, male
External urethral
orifice
Degenerating pronephros
Urogenital
ridges
Yolk sac
Mesonephros
Allantois
Mesonephric duct
Hindgut
Metanephros:
Cloacal membrane
Ureteric bud
Cloaca
Metanephric
mesoderm
(a) Fifth week
Gut
Degenerating pronephros
Allantois
Urinary bladder
Genital tubercle
Urogenital sinus
Mesonephros
Rectum
Mesonephric duct
Metanephros
(b) Sixth week
Gonad
Urinary bladder
Urogenital sinus
Rectum
Ureter
(c) Seventh week
Gonad
Urinary bladder
Kidney
Urogenital sinus
Anus
Ureter
Rectum
(d) Eighth week
Kidney
Urinary bladder
Ureter
Urogenital sinus
Anus
Allantois
(e) Anterior view, 8-week embryo