1. Health Science Technology Dr. Halbert
Urinary System
Health Science Technology
Dr. Halbert

3. Urinary system = excretory system
Removes some wastes & excess water and maintains pH balance
Consists of 2 kidneys, 2 ureters, bladder and urethra

4. Kidney
On either side of vertebral column separated from the abdominal cavity by peritoneum
Enclosed in a mass of fatty tissue called adipose capsule
Also covered by tough fibrous tissue called renal fascia or fibrous capsule

5. Kidney structure 2 main sections
Cortex
Medulla
Cortex: outer section, contains most of the nephrons
Medulla: inner section, contains most of the collecting tubules, which carry the urine from the nephrons thru the kidney

6. Hilum
Notched or indented area of the kidney thru which ureter, blood vessels & lymph vessels enter & leave kidney

7. Nephron Filtering unit of kidney One million nephrons per kidney
Consists of
Glomerulus
Bowman’s capsule
Proximal convoluted tubule
Distal convoluted tubule
Collecting duct

8. Glomerulus First part of nephron Cluster of capillaries
As blood passes thru from renal artery, water, mineral salts, sugar are filtered out of blood
RBCs & proteins are not filtered out
Filtered blood makes its way to renal vein

9. Bowman’s capsule
C-shaped structure that surrounds the glomerulus & is start of convoluted tubule
Picks up filtered material from glomerulus & passes them to convoluted tubule

10. Passing through tubules
Substances needed by body are reabsorbed & returned to blood capillaries
Excess sugar, mineral salts; some water; & wastes remain in tubule & become urine
Urine enters collecting ducts located in medulla

11. Renal Pelvis
Collecting ducts empty into renal pelvis, funnel-shaped structure which is first section of ureter

12. Ureters Two muscular tubes About 10-12 inches
Peristalsis moves urine through the ureter to the bladder

13. Bladder
Hollow muscular sac that lies behind the symphysis pubis & at midline of pelvic cavity
Mucous membrane lining arranged in folds, rugae which disappear as bladder expands with urine

14. Bladder wall Formed by three layers of smooth muscle
Bladder stores urine until eliminated
Urge to void occurs when bladder contains 250 cc (1 cup) of urine but bladder can hold much more

15. Sphincter
Circular muscle controls opening of bladder to prevent emptying

16. Urethra Tube that carries urine from the bladder to the outside
External opening is the urinary meatus

17. Urethra Male vs Female Female Male 3.75 cm (1½ in) Carries only urine
Opens in front of vagina
Male
20 cm (8 in)
Carries urine & semen
Passes through prostate & out through penis

18. Urine Liquid waste product produced by urinary system 95% water
Waste products: urea (major waste product), uric acid, creatinine, mineral salts, pigments
Urochrome: pigment giving urine its yellow color
About 1½ to 2 quarts produced daily from 150 quarts of liquid that is filtered through the kidney

19. Terms Polyuria: excessive urination
Oliguria: decreased amounts of urine
Anuria: absence of urine
Hematuria: blood in urine
Pyuria: pus in urine
Nocturia: urination at night
Dysuria: difficult or painful urination
Retention: inability to empty the bladder
Incontinence: involuntary urination

20. Diseases of Urinary System

21. Cystitis Inflammation of the bladder
Usually caused by pathogens entering urinary meatus
More common in females

22. Glomerulonephritis Inflammation of the glomerulus
Acute form: usually follows a streptococcal infection
Chronic form: progressive disease that causes scarring of the glomeruli leads to kidney failure

23. Pyelonephritis
Inflammation of kidney tissue & renal pelvis usually caused by bacteria

24. Renal calculus Kidney stone
Calculus is formed when salts in the urine precipitate
May become lodged in renal pelvis or ureter

25. Renal failure When kidneys stop functioning
Acute renal failure (ARF): caused by hemorrhage, shock, poisoning, injury, dehydration
Chronic renal failure (CRF): results from progressive loss of kidney function, caused by hypertension, toxins, endocrine disease, chronic glomerulonephritis

26. Uremia
Toxic condition that occurs when kidneys fail & waste products are present in blood stream

27. Urethritis
Inflammation of the urethra usually caused by bacteria, viruses or chemicals

28. Image Citations
Slide 3: Anatomy of the urinary system, front view, 1/1/07,
Slide 5: Illustration of the anatomy of the kidney, 1/1/07,
Slide 8: Glomerulus, 2/17/07,
Slide 13: Male Bladder & urethra, 2/17/07,
Slide 18: Urine, 2/17/07,
Slide 21: Cystitis, 2/17/07,