A simple introduction to the anatomy of the urinary system for humans

1. Anatomy of Urinary
System
Salah Nazar Abdulwahhab M.Sc. Nursing
www.slideshare.net
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2. Facts about urinary system
- Kidneys process over 180 liters of fluid a day
- Actual urine production is limited between 0.5 to 2.5 liters a day
- Remove of waste
- Storage of urine
- Excretion of urine
- Maintain electrolyte, acid-base, and fluid balance of blood
- Release of hormones like calcitriol, erythropoietin and rennin-
angiotensin
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3. Urine Composition
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4. Urinary System Organs
The urinary system composed of:
1) 2 Kidneys
2) 2 Ureters
3) 1 Urinary Bladder
4) 1 Urethra
- Kidneys lie outside peritoneum on the posterior abdominal wall
- one on each side of the vertebral column
- covered in protective fat
- Right kidney is lower than left
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5. Urinary System Organs
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6. Filtration Process
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7. The kidney
The kidney is :
- Bean shaped, Reddish Brown, About 11 cm long, Width : 6cm, Thickness : 3cm,
Weight (135g _150g), between T11 & L3,
- Attached to ureters, renal blood vessels, and nerves at renal hilum
- Top of each kidney is an adrenal gland
- Renal capsule – Surrounding each kidney
The kidney consisting of 3 regions:
1- Renal cortex – outer region
2- Renal medulla – inside the cortex
3- Renal pelvis – inner collecting tube7

8. Kidney Structure
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9. The Nephron
The kidney contains about (1 million nephrons).
- The Nephron is the basic functional unit of the kidney.
- Responsible for forming urine
A nephron consists of :
1. Blood vessels
- Afferent arteriole
- Glomerulus Bowman’s capsules (double walled cup)
- Efferent arteriole
2. Renal tubules
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule9

10. The Nephron Structure
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11. The Ureters
The Ureters are a pair of narrow muscular slender tubes
attaching the kidney to the bladder
- Continuous with the renal pelvis
- Transport urine from the kidneys to urinary bladder.
- Each Ureters is about 25cmlong
- The upper half lies in the abdomen and the lower half in the
pelvis.
- Enters posterior portion of the bladder
- Runs behind the peritoneum
- Peristalsis and gravity aids in urine transport
The lumen of the ureters is composed of three layers:
– Outer layer = Fibrous tissue
– Middle layer = Muscle
– Inner layer = Epithelium
11 Ureter- Cross Section

12. Urinary Bladder
- The urinary bladder is: a hollow smooth collapsible muscular organ
- Act as the reservoir for the urine that received it from kidneys to discharge it Out of the body
through Urethra.
- Empty bladder situated within the pelvis .
- When distended , it rises up to the abdominal cavity
- The normal capacity of the bladder is 300 to 500 mL
Consist of 3 layers
– Outer layer = connective tissue
– Middle layer = Smooth muscle and elastic fibers
– Inner layer = Lined with transitional epithelium
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13. Bladder and Urethra
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14. The Urethra
The urethra is a thin-walled canal, extending from the neck of the bladder to the external urethral
orifice.
- Join to the bladder at its inferior surface.
- Male: about 18 - 20 cm.
In Males – carries urine & sperm cells
- Female: 3-4 cm., carries urine only
Release of urine is controlled by two sphincters
1. Internal Urethral sphincter (involuntary control)
2. External Urethral sphincter (voluntary control)
Both sphincter muscles must open to allow micturition (voiding).
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15. Thank You
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