Download Kidney - Stephen Tavoni

Figure 24.1 The urinary system.
Hepatic veins (cut)
Esophagus (cut)
Inferior vena cava
Adrenal gland
Aorta
Renal artery
Renal hilum
Renal vein
Kidney
Iliac crest
Rectum (cut)
Uterus (part of female
reproductive system)
Ureter
Urinary
bladder
Urethra
© 2014 Pearson Education, Inc.
Figure 24.2a Position of the kidneys against the posterior body wall.
Anterior
Inferior
vena cava
Aorta
Peritoneum
Peritoneal cavity
(organs removed)
Supportive
tissue layers
• Renal fascia
anterior
posterior
Renal
vein
Renal
artery
• Perirenal
fat capsule
• Fibrous
capsule
Body of
vertebra L2
Body wall
Posterior
© 2014 Pearson Education, Inc.
Figure 24.3a Internal anatomy of the kidney.
Renal
hilum
Renal cortex
Renal medulla
Major calyx
Papilla of
pyramid
Renal pelvis
Minor calyx
Ureter
Renal pyramid in
renal medulla
Renal column
Fibrous capsule
© 2014 Pearson Education, Inc.
Photograph of right kidney, frontal section
Figure 24.5 Location and structure of nephrons. (1 of 7)
Renal cortex
Renal medulla
Renal pelvis
Kidney
Renal corpuscle
• Glomerular capsule
• Glomerulus
Ureter
Distal
convoluted
tubule
Proximal
convoluted
tubule
Cortex
Medulla
Thin segment
Nephron loop
• Descending limb
• Ascending limb
© 2014 Pearson Education, Inc.
Thick
segment
Collecting
duct
Figure 24.7b Blood vessels of cortical and juxtamedullary nephrons.
Peritubular
capillary bed
Glomerulus
Afferent
arteriole
Efferent
arteriole
© 2014 Pearson Education, Inc.
Figure 24.6b Renal cortical tissue.
© 2014 Pearson Education, Inc.
Scanning electron micrograph
of renal tubules (250x)
Figure 24.6a Renal cortical tissue.
Distal convoluted
tubules (clear lumens)
Renal corpuscle
• Squamous epithelium
of parietal layer of
glomerular capsule
• Glomerular capsular
space
• Glomerulus
Proximal convoluted
tubules (fuzzy lumens
due to long microvilli)
Photomicrograph of renal cortical tissue (180x)
© 2014 Pearson Education, Inc.
Figure 24.7b Blood vessels of cortical and juxtamedullary nephrons.
Peritubular
capillary bed
Glomerulus
Afferent
arteriole
Efferent
arteriole
© 2014 Pearson Education, Inc.
Figure 24.5 Location and structure of nephrons. (1 of 7)
Renal cortex
Renal medulla
Renal pelvis
Kidney
Renal corpuscle
• Glomerular capsule
• Glomerulus
Ureter
Distal
convoluted
tubule
Proximal
convoluted
tubule
Cortex
Medulla
Thin segment
Nephron loop
• Descending limb
• Ascending limb
© 2014 Pearson Education, Inc.
Thick
segment
Collecting
duct
Figure 24.8 Juxtaglomerular complex (JGC) of a nephron.
Glomerular
capsule
Efferent
arteriole
Glomerulus
Parietal layer
of glomerular
capsule
Capsular
space
Afferent
arteriole
Foot
processes
of podocytes
Podocyte cell body
(visceral layer)
Red blood cell
Proximal
tubule cell
Efferent
arteriole
Juxtaglomerular
complex
• Macula densa
cells
of the ascending
limb of nephron loop
• Extraglomerular
mesangial cells
• Granular
cells
Afferent
arteriole
Lumens of
glomerular
capillaries
Endothelial cell
of glomerular
capillary
Glomerular mesangial
cells
Juxtaglomerular complex
© 2014 Pearson Education, Inc.
Renal corpuscle
Figure 24.5 Location and structure of nephrons. (1 of 7)
Renal cortex
Renal medulla
Renal pelvis
Kidney
Renal corpuscle
• Glomerular capsule
• Glomerulus
Ureter
Distal
convoluted
tubule
Proximal
convoluted
tubule
Cortex
Medulla
Thin segment
Nephron loop
• Descending limb
• Ascending limb
© 2014 Pearson Education, Inc.
Thick
segment
Collecting
duct
Figure 24.7a Blood vessels of cortical and juxtamedullary nephrons.
Cortical nephron
• Short nephron loop
• Glomerulus further from the cortex-medulla junction
• Efferent arteriole supplies peritubular capillaries
Renal
corpuscle
Glomerulus
(capillaries)
Efferent
arteriole
Glomerular
capsule
Proximal
convoluted
tubule
Juxtamedullary nephron
• Long nephron loop
• Glomerulus closer to the cortex-medulla junction
• Efferent arteriole supplies vasa recta
Cortical radiate vein
Cortical radiate artery
Afferent arteriole
Collecting duct
Distal convoluted tubule
Afferent
Efferent
arteriole
arteriole
Peritubular
capillaries
Ascending
limb of
nephron loop
Kidney
Cortex-medulla
junction
Arcuate vein
Arcuate artery
Vasa recta
Nephron loop
Descending
limb of
nephron loop
© 2014 Pearson Education, Inc.
Figure 24.9 A schematic, uncoiled nephron showing the three major renal processes that adjust plasma composition.
Afferent
arteriole
Glomerular
capillaries
Efferent arteriole
Cortical
radiate
artery
1
Glomerular capsule
Renal tubule and
collecting duct
containing filtrate
2
Peritubular
capillary
3
To cortical radiate vein
Three major
renal processes: Urine
Glomerular filtration
1
Tubular reabsorption
2
Tubular secretion
3
© 2014 Pearson Education, Inc.
Figure 24.4b Blood vessels of the kidney.
Aorta
Inferior vena cava
Renal artery
Renal vein
Segmental artery
Interlobar vein
Interlobar artery
Arcuate vein
Arcuate artery
Cortical radiate artery
Afferent arteriole
Cortical radiate vein
Peritubular
capillaries
or vasa recta
Efferent arteriole
Glomerulus (capillaries)
Nephron-associated blood vessels
(see Figure 24.7)
(b)Inc.Path of blood flow through renal blood vessels
© 2014 Pearson Education,
Figure 24.7a Blood vessels of cortical and juxtamedullary nephrons.
Cortical nephron
• Short nephron loop
• Glomerulus further from the cortex-medulla junction
• Efferent arteriole supplies peritubular capillaries
Renal
corpuscle
Glomerulus
(capillaries)
Efferent
arteriole
Glomerular
capsule
Proximal
convoluted
tubule
Juxtamedullary nephron
• Long nephron loop
• Glomerulus closer to the cortex-medulla junction
• Efferent arteriole supplies vasa recta
Cortical radiate vein
Cortical radiate artery
Afferent arteriole
Collecting duct
Distal convoluted tubule
Afferent
Efferent
arteriole
arteriole
Peritubular
capillaries
Ascending
limb of
nephron loop
Kidney
Cortex-medulla
junction
Arcuate vein
Arcuate artery
Vasa recta
Nephron loop
Descending
limb of
nephron loop
© 2014 Pearson Education, Inc.
Figure 24.11 Forces determining net filtration pressure (NFP).
Glomerular
capsule
Efferent
arteriole
HPgc = 55 mm Hg
OPgc = 30 mm Hg
Afferent
arteriole
HPcs = 15 mm Hg
NFP = Net filtration pressure
= outward pressures – inward pressures
= (HPgc) – (HPcs + OPgc)
= (55) – (15 + 30)
= 10 mm Hg
© 2014 Pearson Education, Inc.
Figure 24.12 Physiological mechanisms regulating glomerular filtration rate (GFR) in the kidneys.
SYSTEMIC BLOOD PRESSURE
Blood pressure in
afferent arterioles; GFR
Granular cells of
juxtaglomerular
complex of kidney
GFR
Inhibits baroreceptors
in blood vessels of
systemic circulation
Release
Stretch of smooth muscle
in walls of afferent
arterioles
Filtrate flow andNaCl in
ascendinglimb of
nephron loop
Targets
Vasodilation of
afferent arterioles
Renin
Sympathetic
nervous system
Catalyzes cascade
resulting in
formation of
Angiotensin II
Macula densa cells of
juxtaglomerular
complex of kidney
Vasoconstriction of
systemic arterioles;
peripheral resistance
Aldosterone
secretion by
adrenal cortex
Release of vasoactive
chemicals inhibited
Vasodilation of
afferent arterioles
Na+ reabsorption
by kidney tubules;
water follows
Blood volume
GFR
Myogenic mechanism
of autoregulation
Systemic
blood pressure
Tubuloglomerular
mechanism
ofautoregulation
Intrinsic mechanisms directly regulate GFR despite
moderate changes in blood pressure (between 80
and 180 mm Hg mean arterial pressure).
© 2014 Pearson Education, Inc.
Hormonal (renin-angiotensinaldosterone)mechanism
Neural controls
Extrinsic mechanisms indirectly regulate GFR
by maintaining systemic blood pressure, which
drives filtration in the kidneys.
Figure 24.5 Location and structure of nephrons. (1 of 7)
Renal cortex
Renal medulla
Renal pelvis
Kidney
Renal corpuscle
• Glomerular capsule
• Glomerulus
Ureter
Distal
convoluted
tubule
Proximal
convoluted
tubule
Cortex
Medulla
Thin segment
Nephron loop
• Descending limb
• Ascending limb
© 2014 Pearson Education, Inc.
Thick
segment
Collecting
duct
Figure 24.13 Transcellular and paracellular routes of tubular reabsorption.
Filtrate
in tubule
lumen
Lateral
intercellular
space
Tight
junction
3
H2O and
solutes
2
1
The transcellular route
involves:
Interstitial
fluid
Tubule cell
4
3
4
Transcellular route
Apical
membrane
H2O and
solutes
Capillary
endothelial
cell
Paracellular route
Basolateral
membranes
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Peritubular
capillary
1 Transport across the apical
membrane.
2
Diffusion through the cytosol.
3
Transport across the basolateral
membrane. (Often involves the
lateral intercellular spaces because
membrane transporters transport
ions into these spaces.)
4 Movement through the
interstitial fluid and into the
capillary.
The paracellular route involves:
• Movement through leaky
tight junctions, particularly in
the PCT.
• Movement through the interstitial fluid and into the
capillary.
Figure 24.14 Reabsorption by PCT cells.
1At the basolateral membrane, Na+ is pumped
into the interstitial space by the Na+-K+ ATPase.
Active Na+ transport
creates concentration gradients that drive:
2“Downhill” Na+ entry at the
apical membrane.
Nucleus
Filtrate
in tubule
lumen
Tubule cell
Interstitial
fluid
Peritubular
capillary
2
Glucose
Amino
acids
Some
ions
Vitamins
Lipidsoluble
substances
Various
Ions
and urea
1
3
3Reabsorption of organic
nutrients and certain ions by
cotransport at the apical
membrane.
4
Reabsorption of water by
osmosis through
aquaporins. Water reabsorption
increases the concentration of the
solutes that are left behind. These
solutes can then be reabsorbed as
they move down their gradients:
5
Lipid-soluble substances diffuse
by the transcellular route.
4
5
6 Various ions (e.g., Cl−, Ca2+,
K+) and urea diffuse by the
paracellular route.
6
Tight junction
Primary active transport
Secondary active transport
Passive transport (diffusion)
© 2014 Pearson Education, Inc.
Paracellular route
Transport protein
Ion channel
Aquaporin