1. The Urinary System Chapter 17

2. Terminology  Nephrology: study of the S/F of the kidney  Urology: Males = specialty of male urinary system + reproductive system Females = speciality of urinary system  Dialysis (hemodialysis): removal of solutes from urine artificially if kidneys are impaired  Incontinence: lack of voluntary control of bladder emptying

3. Dialysis

4. 4 Functions of Urinary System  Regulate blood volume & composition (kidneys)  Transportation of filtrate (ureters)  Storage of urine (urinary bladder)  Discharge of waste/excretion (urethra)

5. Kidneys - 2  Sit above waist  Back of abdominal cavity (retroperitoneal)  Right kidney sits lower than left  4-5 inches long, 2-3 inches wide, 1 inch thick [bar of soap]  Surrounded by adipose tissue  Hilus: where vessels enter/exit

6. Layers of the kidney  Renal cortex (bark)  Renal medulla (middle) Renal pyramids here  Renal pelvis (inner) Funnel-shaped basin for draining urine

7. Basic Functioning Unit of Kidney  The Nephron – p. 474-475  2 parts: Renal corpuscle (cortex) = filtration  Glomerulus  Glomerular (Bowman’s) capsule Renal tubules (cortex & medulla) = reabsorption  Proximal convoluted tubule  Loop of Henle  Distal convoluted tubule  Collecting duct

8. The Nephron

9. Did you know…  Only 1% of what your kidneys filter is excreted as urine  The other 99% is water and is reabsorbed to prevent dehydration  Which hormones control this action??

10. Ureters - 2  Transport urine from kidneys to urinary bladder  Empty posteriorly and inferiorly into urinary bladder

11. Urinary Bladder - 1  For storage  Capacity = ¾ quart (600mL) Usually signals start at 150mL full  Trigone: area made by ureters and urethra; triangular area with no folds  Lots of folds to allow for stretching  Do you remember what tissue makes up the urinary bladder?

12. Urinary Bladder

13. Urination reflex  To empty the bladder = urination, voiding, micturition  Spinal cord reflex  Controlled by 2 sphincters (similar to defecation reflex) Internal sphincter = released involuntarily when bladder reaches a certain capacity; controlled by detruser muscle External sphincter = voluntarily controlled to release urine when appropriate

14. Urethra - 1  Tube that discharges urine from body  Terminal end = urinary meatus  In males, it also dicharges semen

15. Urinalysis  Analysis of volume, physical, chemical & microscopic urine properties  Normal characteristics 95% water Volume: 1-2L (varies with fluid intake) Color: yellow/amber  clear Turbidity: clear/transparent Odor: after time, mild ammonia pH: 4.6 – 8.0 (varies with fluid intake) Specific gravity/density: 1.001 – 1.0035 (slightly more dense than water = 1) Normal solutes: urea, uric acid, amino acids

16. Urinalysis continued  Abnormal solutes: Albumin (protein) (proteinuria) Glucose Ketones (ketonuria) Blood (hematuria) Stones

17. Disorders  Urinary Tract Infection (UTI): bacterial infection in any part of the urinary system Cystitis: infection of urinary bladder Nephritis: infection of kidney (nephron)  Polyuria: increased urine production  Nocturia: increased urine output at night  Dysuria: painful urination; often associated with UTIs and STDs  Uremia/uremic poisoning: toxic levels of urea in the blood due to kidney failure