1. The Urinary System Components: 2 kidneys 2 ureters urinary bladder
urethra

2. The Kidneys Excrete metabolic wastes Maintain homeostasis (6 ways)
Supplied by renal arteries , drained by renal veins
The kidneys remove waste from the blood, then excrete them as urine. The urine is transported passively to the ureters, urine carried down the ureters to urinary bladder by peristalisis and gravitational forces.

3. Anatomy of the Kidney Located on the back wall of the abdominal cavity
Surrounded by fat for protection (they easily bruise); caps on top are the adrenal glands
Ribs protect the upper half of the kidneys
Filter/clean blood with structures called nephrons (functional units)
There are ~ 1 million nephrons per kidney

4. Urination The process of eliminating urine from the body
ADD THESE NOTES TO THE BOTTOM OF YOUR PAGE:
The process of eliminating urine from the body
Also known as Micturation
A sphincter muscle controls the opening to the bladder
Is under nervous control

7. THE NEPHRON

8. Excretion
The Removal of waste products from the body

9. What types of wastes does the Human Body produce?
Primary Metabolic Wastes incl:
Carbon Dioxide
Water
Ammonia
Mineral Salts
The Main Excretory Organs are the lungs,
kidneys, rectum and skin
Primary metabolic waste – means:

10. Some Major Organs and their waste products
Primary Waste
Secondary Waste
Kidney
Urine through water,
N2 wastes, salts
Carbon dioxide,
Heat
Rectum
Food wastes, bacteria
Feces
Carbon dioxide, heat, water, salts, and methane!
Lungs
Carbon dioxide
Water vapor
Skin
Sweat = urea, water, salt
Look up the deal on methane

11. Consequences if Fluid Intake is not equal to Fluid output
High fluid output can occur due to many reasons:
Consumption of diuretics or kidney malfunction (examples of diuretics….? Write them down)
Large amounts of perspiration (sweating)
Increased exhalation (exercise)
Prolonged bouts of diarrhea
These conditions along with low fluid intake can lead to ? Dehydration

12. Dehydration
When body’s fluid output is greater than fluid input – body attempts to restore homeostasis:
If output exceeds intake by (% of dehydration occurring or % of total body mass)
1% : thirst sensation to get lost fluids replaced
5%: pain and collapse to conserve water, exhalation is reduced
10%: death!!

13. Roles of the Liver in Excretion
Transforms toxins (ex. Alcohol and heavy metals) into soluble compounds
Transforms hazardous products of protein metabolism into safer products
Ammonia is converted to urea, and also: ketones
Look up heavy metals, and ketones

14. TWO Major Roles of the Kidney
1. Excretion of Nitrogenous and other wastes – making and releasing urine
2. Maintaining Homeostasis – by many different ways (see other handout)

15. Composition of Urine Water – 95% - from food and drinks PLUS
N – Urea – 2% - from detoxified ammonia
N – Uric Acid – broken down nucleic acids (DNA)
N – Creatinine – 1.5% - from muscles as they work (involved with ATP being used)
Excess salt ions – 1.4% - from food and drinks
N – Ammonia – 0.05% from breaking down proteins (amino acids  ammonia)
Detoxified means – liver converting ammonia into urea

16. Composition of Urine
N – Ammonia – 0.05% from breaking down proteins (amino acids  ammonia)
N – Ketones – .03% - from broken down body fat (higher in diabetics and ppl losing body fat)
N – Urochrome – .02% - from broken down red blood cells – is what gives urine its yellow color

17. Fluid Balance

18. How The Kidney Maintains Homeostasis
6 ways
Read the page
Fun quiz afterwards! ??

19. T/F ?? The Kidneys clean blood by filtering it 
2. T/F ?? The Kidneys can put sugar into urine if there’s too much sugar in the blood
3. T/F ?? The kidneys make more urine when the blood doesn’t have enough water
4. T/F ?? The kidneys can put more salt in the urine if the blood is too salty
5. Osmoregulation is 
a) Regulation of the water content of the blood
b) Regulation of the salt content of the blood
c) Regulation of the water content in the urine
d) Regulation of the salt content in the urine
e) All of the above

20. 6. T/F ?? [OH –] ions are acid ions
7. What kind of ions will the urine contain after a person eats lemons and oranges? (Acid or Base??)
Y/N ?? Can the kidney control how many red blood cells are in the
blood?
9. How does the kidney do this?
10. T/F ?? The kidneys help to balance the composition of blood by adding or subtracting things to the urine.

21. T/F ?? The Kidneys clean blood by filtering it 
True
T/F ?? The Kidneys can put sugar into urine if there’s too much sugar in the blood
T/F ?? The kidneys make more urine when the blood doesn’t have enough water
False
T/F ?? The kidneys can put more salt in the urine if the blood is too salty
5. Osmoregulation is 
e) All of the above

22. T/F ?? [OH –] ions are acid ions
False
What kind of ions will the urine contain after a person eats lemons and oranges? (Acid or Base??)
Acid
Y/N ?? Can the kidney control how many red blood cells are in the
blood?
Yes
How does the kidney do this?
By releasing the hormone Erythroprotein
which tells the bone marrow to make more rbc’s
T/F ?? The kidneys help to balance the composition of blood by adding or subtracting things to the urine.
True