1. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Memmler’s The Human Body in Health and Disease 11 th edition Chapter 22 The Urinary System

2. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins ExcretionExcretion Body systems work interdependently to maintain homeostasis by excretion Urinary Digestive Respiratory Integumentary

3. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Organs of the Urinary System Two kidneys Two ureters Single urinary bladder Single urethra

4. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Male urinary system, showing blood vessels. Zooming In: What vessel supplies blood to the kidney? What vessel drains the kidney?

5. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Kidney Activities Excretion –Urea Water balance maintenance Body fluid acid–base regulation Blood pressure regulation –Angiotensin –Aldosterone Red blood cell production regulation

6. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Kidney Structure Membranous renal capsule of fibrous connective tissue Adipose capsule of fat Fascia anchors kidney to peritoneum and abdominal wall Retroperitoneal space Right kidney lower than left to accommodate liver

7. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Blood Supply to the Kidney Renal artery supplies blood Nephrons are functional units Renal vein drains blood

8. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Kidney Organization Hilum Renal cortex (outer portion) Renal medulla (inner portion) –Renal pyramids Renal pelvis –Calyces

9. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Longitudinal section through the kidney. Its internal structure is shown (left), along with an enlarged diagram of nephrons (right). Each kidney contains more than 1 million nephrons.

10. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Nephron Functional kidney unit Glomerular (Bowman) capsule –Glomerulus –Afferent arteriole Peritubular capillaries Proximal convoluted tubule (PCT) Nephron loop (Loop of Henle) –Descending limb –Ascending limb Distal convoluted tube (DCT) Collecting duct

11. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins A nephron and its blood supply. The nephron regulates the proportions of water, waste, and other materials according to the body’s constantly changing needs. Materials that enter the nephron can be returned to the blood through the surrounding capillaries. Zooming In: Which of the two convoluted tubules is closer to the glomerular capsule? Which convoluted tubule is farther away?

12. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Formation of Urine Glomerular filtration –Glomerular filtrate Tubular reabsorption –Diffusion –Osmosis –Active transport Tubular secretion Countercurrent mechanism –Concentration of urine –Antidiuretic hormone (ADH)

13. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Summary of urine formation in a nephron.

14. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Control of Blood Pressure Juxtaglomerular apparatus: Specialized cells that regulate kidney function Triggered by low blood pressure –Secretes renin enzyme

15. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Structure of the juxtaglomerular (JG) apparatus. Note how the distal convoluted tubule contacts the afferent arteriole (right). Cells in these two structures make up the JG apparatus. Zooming In: The JG apparatus is made up of cells from which two structures?

16. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Ureters Long, slender, muscular tubes –Epithelial cell lining –Involuntary muscle layer –Fibrous connective tissue coat Entirely extraperitoneal Extend from kidney to urinary bladder Move urine by gravity and peristalsis

17. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Urinary Bladder Temporary reservoir for urine Multiple layers Mucous membrane –Transitional epithelium –Rugae –Connective tissue –Three-layered coat of involuntary muscle tissue –Incomplete coat of peritoneum Trigone

18. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Urethra Tube that extends from the bladder to the outside Male –Part of both reproductive and urinary systems Female –Entirely separate from reproductive system

19. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Urination Process of expelling urine from bladder (micturition) Involuntary control –Internal urethral sphincter Voluntary control –External urethral sphincter

20. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Urine 95% water, 5% dissolved solids and gases pH averages 6.0 Specific gravity measures amount of dissolved substances –Normal range 1.002 to 1.040

21. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Normal Constituents Dissolved solids normally found in urine Nitrogenous waste products –Urea –Uric acid –Creatinine Electrolytes –Sodium chloride –Sulfates –Phosphates Pigment

22. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Abnormal Constituents Urinalysis is evaluation of urine Glucose –Glycosuria Albumin –Albuminuria Blood –Hematuria Ketones –Diabetes mellitus and starvation White blood cells –Pyuria Casts –Nephron disease

23. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Disorders of the Urinary System Portion of urinary system most prone to disorders is kidney

24. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Kidney Disorders Kidney disorders may be acute or chronic Acute glomerulonephritis –Most common kidney disease Pyelonephritis Hydronephrosis Polycystic kidney Tumors Kidney stones (calculi) Renal failure –Leads to uremia, high levels of nitrogenous waste in the blood

25. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Renal Dialysis and Kidney Transplantation Dialysis –Hemodialysis –Peritoneal dialysis Kidney transplantation –Final option for treatment of kidney failure

26. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Disorders of the Ureters Subdivision at renal pelvis Constricted or abnormally narrow parts (strictures) Renal ptosis Ureterocele Ureteral stones

27. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Bladder Disorders Rupture Cystitis –Interstitial cystitis Tumors –90% arise from epithelial lining –If bladder removed (cystectomy), ureters diverted to part of ileum in an ilial conduit Urinary incontinence –Stress incontinence –Urge incontinence –Overflow incontinence –Enuresis

28. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Disorders of the Urethra Congenital anomalies –Narrowing of opening or urethra itself –Presence of valve-like structure at junction of urethra and bladder –Hypospadias Urethritis Straddle injuries

29. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Effects of Aging Loss of ability to concentrate urine Decrease in number and size of nephrons Increase in blood urea nitrogen (BUN) Urinary infections Prostate enlargement Decreased bladder capacity Incontinence

30. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins End of Presentation