1. Can you hold it long enough for me to get through this lecture?
Urinary System
Can you hold it long enough for me to get through this lecture?

2. QUICK REVIEW OF ELIMINATION
Lungs eliminate CO2
Sweat glands eliminate excess heat, salt
Digestive tract- indigestible solids, bacteria
Urinary tract is the main system of elimination

3. The Urinary Tract
Urinary tract consists of 2 kidneys, 2 ureters, one bladder and one urethra.
Kidney location:
Dorsal wall of abdominal cavity
12th thoracic and 3rd lumbar vertebrae
Urethra
1.5 inches in women, 8 inches in men

4. Kidney
Outer layer- Cortex
Inner layer- Medulla
Calyx- collects urine as it is formed, join together to form the ureter

5. Kidneys filter blood- 2, 000 L/day (500 gal)
remove waste products and reabsorb water, other valuable substances.
1.5 L of urine/day
Metabolism produces toxic substances- esp nitrogen containing waste as a by-product of protein breakdown
We eliminate nitrogen as urea- water soluble

6. The main functional unit of the kidney is called the NEPHRON.
1 million per kidney

7. Urine is made in 4 steps
Filtration
Reabsorption
Secretion
Excretion
A urinalysis is the most common non-invasive medical test
ordered

8. Diseases of the Kidney Acute Kidney failure- sudden loss of function
Causes: nephritis, shock, injury, heart failure or poisoning
Symptoms: anuria or oliguria. Uremia, nausea, coma, death
Chronic Kidney failure- gradual loss of function due to hypertension (high blood pressure) or endocrine disease
Cystitis- inflammation of the urinary bladder

9. Dialysis, Kidney transplant
Hemodialysis- serves as an “artificial kidney” 2-3x/week for 2-4 hours
Peritoneal dialysis- uses patient’s own peritoneal lining to filter blood
Kidney transplant- need suitable donor. Only need one, but must take anti-rejection drugs for the life of the patient