EDUCATIONAL PURPOSE

1. THE URINARY SYSTEM
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2. Introduction
 Urology is the branch of medicine that deals
with the urinary system.
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3. Functions of the Urinary system
 1. Regulating blood volume and pressure
 2. Regulating plasma concentrations of sodium,
potassium, chloride and other ions
 3. Stabilising blood pH
 4. Conserving nutrients
 5. Detoxifying poisons (with the liver) 3

4. Basic Gross Anatomy
 Two kidneys
 Two ureters
 Urinary bladder
 Urethra
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5. External Anatomy of the Kidneys
 Within the muscular
wall of the back
between T12-L3.
 Renal hilus
 Connective tissue
layers:
 Renal capsule
 Adipose capsule
 Renal fascia
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6. Internal Anatomy of the Kidneys
 Renal Cortex
 Renal Medulla
 Renal pyramids
 Renal papillae
 Renal columns
 Renal Pelvis
 With major calyces
and minor calyces
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7. - The medial surface of the kidney is concave with
a hilum carrying renal nerves and blood vessels.
The renal parenchyma is divided into an outer
cortex and inner medulla.
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8. Extensions of the cortex
(renal columns) project
toward the sinus, dividing
the medulla into 6-10 renal
pyramids.
Each pyramid is conical
with a blunt point called the
papilla facing the sinus.
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9. The papilla is nestled
into a cup called a minor
calyx, which collects its
urine. Two or three
minor calyces merge to
form a major calyx. The
major calyces merge to
form the renal pelvis.
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10. Blood Supply of the Kidney
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11. Nephron Anatomy
 Renal Corpuscle
 Glomerulus
 Bowman’s capsule
 Renal Tubules
 Proximal convoluted
tubule (PCT)
 Loop of Henle
 Distal convoluted
tubule (DCT)
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12. Urine Storage and Elimination:
The Ureters
The ureters are muscular tubes leading from the
renal pelvis to the lower bladder.
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13. Ureter- Cross Section
 3 layers of tissue
 Outer layer
 Fibrous tissue
 Middle layer
 Muscle
 Inner layer
 Epithelium
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14. The Urinary Bladder
- is a muscular sac on the floor of the pelvic cavity.
- is highly distensible and expands superiorly.
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15. The openings of the two ureters and the urethra mark a
triangular area called the trigone on the bladder floor.
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16. The Urethra
- conveys urine from the urinary bladder to the
outside of the body.
Females male
3-4 cm ~18 cm
greater risk of
urinary tract
infections
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17. The male urethra has three
regions:
1) prostatic urethra
2) membranous urethra
3) penile urethra.
Difficulty in voiding urine with enlarged prostate
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18. In both sexes:
- internal urethral sphincter- under involuntary control.
- external urethral sphincter - under voluntary control
internal urethral sphincter
external urethral sphincter
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19. Urethra- structure of
 Muscle layer
 Submucosa layer
 Mucosa
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20. Spinal
cord
Voiding Urine in infants
micturition reflex
When the bladder contains about 200 ml of urine, stretch receptors in the wall send
impulses to the spinal cord. Parasympathetic signals return to stimulate contraction
of the bladder and relaxation of the internal urethral sphincter.
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21. 2. Once voluntary control has developed, emptying of the bladder
is controlled predominantly by a micturition center in the pons. This
center receives signals from stretch receptors and integrates this
information with cortical input concerning the appropriateness of
urinating at the moment. It sends back impulses to stimulate
relaxation of the external sphincter.
Once voluntary control has developed, emptying of the
bladder is controlled predominantly by a micturition center
in the pons. This center receives signals from stretch
receptors and integrates this information with cortical input
concerning the appropriateness of urinating at the
moment. It sends back impulses to stimulate relaxation of
the external sphincter.
Voiding Urine in adults
Voluntary
control
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