The State Medical and Pharmaceutical University “Nicolae Testemitanu”
Republic of Moldova
Department of
Human Anatomy
The Urinary
System
Lecturer Globa Lilian
Uro-genital Apparatus

Urinary System
for secretion and
discharge of the urine

Genital System
concerned with process of
reproduction
Have common sources and ways of the development,
topographic sites, blood and nerve supply
Overview of the Urinary System
4 components
Functions



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Controlling the water and electrolyte balance,
maintain the acid-base balance
Regulates blood concentrations of sodium,
potassium, chloride and calcium
Regulates blood volume and blood pressure
Production of urine- waste products (urea and
uric acid)
Reabsorb important nutrients from urine
Endocrine (rennin, angiotensin, erythropoietin)
Anatomy
1. Kidney
Each kidney is about:
Length 11.25 cm
Breadth 5-7.5 cm
Width 2.5 cm
The weight:
Male 125-175 g
Female 115-155 g
Anatomy
2. Ureter
* Connects
kidney to
urinary
bladder
Anatomy
3. Urinary
bladder
* Stores
urine
Anatomy
4. Urethra
* Drains
urine from
bladder
Coverings of the Kidneys
The kidneys have the
following coverings:

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Fibrous capsule
Perirenal fat
Renal fascia with
anterior and posterior
layers
Pararenal fat
Fixation of the Kidneys
The elements that held kidneys in position:




Peri- and para renal fat
Renal fascia with anterior and posterior layers
Vascular pedicle
Intrabdominal pressure
Anatomy of the Kidney
Outer cortex
Inner medulla
Medulla
Medulla divided
into pyramids
and columa
renalis
One pyramid
with
corresponding
cortex form
renal lobe
Cortex
Cortex divided
into pars
convoluta and
pars radiata
Calyx
One minor
calyx per
pyramid
Minor Calyx
Major Calyx
Fusion of several
minor calyces
Usually 2-3
major calyces
per kidney
Fornical Apparatus
Renal Pelvis
Fusion of
major calyces
Opening to the
ureter
Human Kidney
Urogram
The Nephron

Basic structural and functional unit of kidney
The Nephron




Filtration of blood
Production of urine
1,25 million per kidney
85 miles of tubes per kidney
Components of Nephron
Renal corpuscle:
1.
a.
b.
2.
3.
4.
Glomerulus – a net-work of convoluted capillaries
Glomerular (Bowman’s) capsule – a hollow
chamber surrounding the glomerulus
Proximal convoluted tubule
Loop of Henle (descending and ascending limbs)
Distal convoluted tubule
The Nephron
The Nephron
Epithelia filter
the urine
Glomerulus
Glomerulus and Capsule
efferent arteriole
urine
afferent arteriole
Proximal Convoluted Tubule
Loop of Henle
only part found
in medulla
The Juxtaglomerular Apparatus
efferent arteriole
urine
afferent arteriole
Distal Convoluted Tubule
Collecting (Straight) Duct
Collecting Duct



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Not part of nephron
Collects urine from distal convoluted tubules
of many nephrons
Opens at tip of pyramid
Urine drains into minor calyx
Collecting Duct
Important Relations, Right Kidney
 Anteriorly:
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the suprarenal gland,
the liver,
the descended part of the duodenum,
coils of jejunum,
the right colic flexure.
Posteriorly:





the diaphragm,
the XII-rib,
the psoas, quadratus lumborum, and transversus
abdominis muscles (the renal lodge)
the costodiaphragmal recess of pleura,
the subcostal, iliohypogastric and ilioinguinal nerves
Important Relations, Left Kidney
 Anteriorly:
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
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the suprarenal gland,
the spleen,
the stomach,
the pancreas,
coils of jejunum,
the left colic flexure.
Posteriorly:





the diaphragm,
the XI-XII rib,
the psoas, quadratus lumborum, and transversus
abdominis muscles (the renal lodge)
the costodiaphragmal recess of pleura,
the subcostal, iliohypogastric and ilioinguinal nerves
Anterior Relation of both Kidneys
1 – area hepatica;
2 – area colica;
3 – area jejunalis;
4 – area duodenalis;
5 – glandulae
suprarenales;
6 – aa. renales;
7 – vv. renales;
8 – area gastrica;
9– area lienalis;
10 – area pancreatica;
11– area colica.
Ureter

Drains urine from kidney to urinary bladder
Length 25-30 cm
Four parts:
1. Abdominal
2. Pelvic
3. Intramural
4. Intravesical
Ureter
Three
constrictions:
1. Ureteropelvic
2. Iliac
3. Ureterovesical
Urinary Bladder
Surfaces:
*Posterior (fundus
or base)
*Anterior (contacts
with pubic
symphysis and
retropubic space of
Retzius )
*Superior (covered
by peritoneum)
Apex continues with
median umbilical
ligament
Neck contains
internal urethral
sphincter
ureter opens
into posterior
wall of
bladder
Internal
urethral
Sphincter
External urethral
Sphincter
Urinary Bladder -- Male
Urinary Bladder -- Female
Development of the kidney
Three sets of structures appear during the development
of the urinary system:
1. Pronephros
2. Mesonephros (Mǖllerian Duct)
3. Metanephros (responsible for permanent kidney)
arise from two sources:
Ureteric Bud
Metanephrogenic Cup
•
•
•
•
•
• Glomerular capsule (covers a cluster
of capillaries - Glomerulus )
• Proximal
• Loops of Henle
• Distal convoluted tubules
Ureter
Pelvis
Major Calyces
Minor Calyces
Collecting Tubules
Abnormalities
VĂ MULȚUMESC PENTRU
ATENȚIE!