The human urinary system consists of the kidneys, ureters, urinary bladder, and urethra. The kidneys filter waste from the blood to produce urine. Each kidney contains millions of nephrons, the functional units that filter blood. Nephrons are composed of a glomerulus for blood filtration and a tubule for urine production and transport. Urine travels from the nephrons through the ureters to the urinary bladder for storage, then exits through the urethra.
3. EXTERNAL STRUCTURE OF A KIDNEY
Renal artery, renal vein, the nerves
are connected to the kidney at the
hilus (a depression at the concave
surface of the kidney).
Hilus
Renal artery
supplies oxygenated
Renal artery blood to the kidney.
Renal vein
Renal vein returns
deoxygenated blood from
the kidney to the heart.
Urine from each kidney
Ureter
passes through the ureter
to the urinary bladder.
5. KIDNEY STRUCTURE
Inner pale
red region
Renal medulla
Outer dark
red region
Renal cortex
Enlarged portion
of the ureter Nephron
Renal pyramid (kidney tubule)
Conical structures Protects the cortex.
Fibrous capsule
in the medulla
6. NEPHRON – THE KIDNEY TUBULE
• The nephron is a
continuous tubule in the
kidney.
• It is made up of
• glomerular capsule
(Bowman’s capsule)
• proximal convoluted tubule
• loop of Henle
• distal convoluted tubule
• collecting duct
8. FLOW OF BLOOD THROUGH THE
KIDNEY
Blood enters the kidney by the renal artery, which gives off
numerous branches or arterioles.
Each branch breaks up into a mass of blood capillaries in the renal capsule. This
mass of blood capillaries is called the glomerulus. The capsule with its
glomerulus is called the renal corpuscle or Malpighian corpuscle.
Blood leaving the glomerulus enters blood
capillaries surrounding the tubule.
These blood capillaries then unite to form venules, which in turn
join to form a branch of the renal vein.
