1. Excretory System

2. Functions
Excretion
removal of organic wastes from
body fluid
Elimination
discharge of waste products
Homeostatic regulation
of blood plasma volume and solute concentration

3. Urinary System Kidney’s – create urine by filtering the blood
Ureters – carry urine from kidney to urinary bladder
Urinary bladder – stores urine
Urethra – tube emptying the urinary bladder

6. Urinary Organs
2 Kidneys
excrete urine
Urinary tract:
Ureters
Urinary bladder
Urethra

7. Kidneys
Filter the blood and remove wastes
Each contain 1-2 million nephrons

10. Blood Supply
The kidneys continuously cleanse the blood and adjust its composition.
Approximately one quarter of the total blood supply of the body passes through the kidneys each minute.
The arterial supply of each kidney is the renal artery

11. Nephrons
Each kidney contains over a million tiny structures called nephrons.
They are the functional unit of the kidneys
Make urine
Control water balance
Regulate blood pressure
Filters 45 gallons of blood/day making 1 ml of urine/min

13. Each nephron consists of
2 main structures:
Glomerulus
Renal Tubule

14. Nephron Component Functions
Glomerulus:
mechanically filters blood
Bowman's Capsule (Glomerular):
Proximal Convoluted Tubule:
reabsorbs 75% of the water, salts, glucose, and amino acids
Loop of Henle:
countercurrent exchange, which maintains the concentration gradient
Distal Convoluted Tubule:
tubular secretion of H ions, potassium, and certain drugs

17. Ureter
Paired tubes
Connects the kidney to the urinary bladder

18. Urinary Bladder
Smooth muscle bag
Stores waste solution - urine

19. Urethra
Connects bladder to outside of the body
Allows urine to pass out of the body

20. Basic Processes of Urine Formation
Filtration
Blood pressure
Water and solutes across glomerular capillaries
Reabsorption
The removal of water and solutes from the filtrate
Secretion
Transport of solutes from the peritubular fluid into the tubular
fluid

22. Urine Composition
Urine is mostly water (about 95% water), however, the rest of the contents of urine can vary depending of what you’ve eaten, drank, breathed or been exposed to.
The remainder of urine usually consists of urea, uric acid, ammonia, hormones, dead blood cells, proteins, salts and minerals, and toxins

24. Incontinence (urine leakage)
More than 10 million Americans experience incontinence
Most do not seek treatment
Treatment can improve or eliminate the problem 90% of the time

25. Kidney Stones Solid mass of tiny crystals
Form when urine contains too much of certain substances
Dehydration

27. Urinary Tract Infection (UTI)
Bacteria (E. coli) from the digestive tract get in the urinary tract
multiply
move from the urethra to the bladder to the kidneys
More common in women than men