1. The Urinary System
Chapter 26

2. Objective
Describe the physiology of urine formation by the kidney.

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

4. Gross Dissection

5. Male Urinary System

6. Female Urinary System

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

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

10. Kidney Dissection
Outer Cortex
Inner Medulla
contain renal pyramids

11. Nephrons Functional unit of the kidneys Makes urine
Controls water balance
Regulates blood pressure

12. Nephrons Glomerulus Bowman’s Capsule Proximal Convoluted Tubule
Loop of Henle
Distal Convoluted Tubule
Collecting Duct

13. Nephron Component Functions
Glomerulus:
mechanically filters blood
Bowman's Capsule:
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

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

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

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

18. 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

20. 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
Main Idea(s) of This Slide -
Although over 10 million Americans suffer from some sort of incontinence, and 90% of these cases can be improved with treatment, most do not seek treatment.

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

23. 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
Main Idea(s) of This Slide -
Urinary tract infections (UTI) are one of the most common type of infections in humans (second only to respiratory infections). UTI can occur when bacteria (commonly E. coli from the digestive tract) gets into the urethral opening and travels up the urethra towards the bladder. If the infection progresses, the bacteria can reach up into the kidneys causing damage to the nephrons.
UTI are much more common in women due to the proximity of the urethral opening to the anus and the much shorter urethra found in women. This is a good time to remind students of male and female anatomy that was presented during the early lessons.