About 20-25% of resting cardiac output (1,200 mL of
blood each minute) flows through the kidneys via the renal
arteries and veins. Within each kidney, the renal artery di-
vides into smaller and smaller vessels, shown in the figure,
that eventually deliver blood to the afferent arterioles.
Each afferent arteriole divides into a tangled capillary
network called a glomerulus (glo-MER-u-lus).
The capillaries of the glomerulus reunite to form an
efferent arteriole. Upon leaving the glomeruluis, each ef-
ferent arteriole divides to form a network of capillaries
around the kidney tubules (described next). These capil-
laries eventually reunite to form veins, which merge into
larger and larger veins. Eventually, all these smaller veins
drain into the renal vein.
THE pLANNER^
Afferent
arteriole
Efferent
arteriole
Blood supply of nephron
Cortical radiate
artery
Arcuate
artery
Renal artery
Renal vein
Arcuate vein
Cortical radiate
vein
Ureter
Vasa recta
Glomerulus
Peritubular
capillary
Cortical
radiate vein
Path of Blood Flow
Renal
a rtery
Segmental arteries
Cortical
ra diate
arteries
A rc u a te arteries
C o rtica l ra diate arteries
A ffe re n t a rte rio le s
Glomerulus
E ffe re n t arteriole s
Peritubular capillaries
Cortical
ra diate
veins
A rcu a te v e in s
In te rlo b a r ve in s
Renal vein
b. Frontal section of right kidney showing path of blood
flow
The Urinary System Plays a Vital Role in Maintaining Homeostasis
441
previous page 476 Craig Freudenrich, Gerard J  Tortora   Visualizing Anatomy and Physiology   2011 read online next page 478 Craig Freudenrich, Gerard J  Tortora   Visualizing Anatomy and Physiology   2011 read online Home Toggle text on/off