1. Unit 4 Notes: The Urinary System

2. (1) Main Organs
Kidneys
Ureters
Bladder
Urethra

4. (2) Functions Filter blood Remove impurities, toxins, excess nutrients
Reabsorb needed water + nutrients

5. (3) Kidney Functions Excretion of nitrogenous wastes
Maintain water concentration of blood
Maintain electrolyte concentration of blood
Regulate blood pH (H ion levels)

6. (4) Ureter, Bladder & Urethra Function
Ureters = Tubes which carry filtered “liquid waste” towards the bladder.
Bladder = Storage tank for filtered “liquid waste”.
Urethra = Tube which allows filtered “liquid waste” to exit body.

8. (5) Kidneys & Blood Supply
Kidneys use 20% of body’s blood
Renal Artery = Entering oxygenated blood
Renal Vein = Exiting deox. Blood
All blood is filtered through nephrons.

10. (6) Nephrons 2 Main Structures:
Glomerulus  Bundle of capillaries w/ blood to be filtered.
Renal Tubule  Tubes following capillaries, which collect filtered contents
Bowman’s Capsule = Portion of tubule where initial filtration and absorption occurs

13. (7) Urine Formation Filtration: Reabsorption: Secretion:
Water + Small Solutes are forced through capillary walls into Bowman’s Capsule.
Reabsorption:
Water, Glucose, Amino Acids & Ions that were filtered out are actively transported back into capillaries and blood.
Secretion:
H ions, K ions, urea, and drugs/toxins are forced through capillary walls into renal tubule.

15. (8) Anatomy of Urine Formation
Filtration  Bowman’s Capsule of Renal Tubule
Reabsorption  Proximal Tube, Loop of Henle & Distal Tubule of Renal Tubule
Secretion  Distal Tubule of Renal Tubule

17. (9) Nitrogenous Wastes
Urea: Byproduct of protein metabolism in the liver.
Uric Acid: Byproduct of nucleic acid metabolism.
Creatinine: Byproduct of creatine metabolism in muscle tissue.

18. (10) Regulating Drops in Blood Pressure
Antidiuretic Hormone (ADH) from Pituitary:
Increases water reabsorption from renal tubule.
Aldosterone from Kidney:
Increases water retention in blood by reabsorbing more sodium from renal tubule.
Angiotensin II from Blood:
Causes vasoconstriction, increasing blood pressure

19. (11) Don’t Pee It Out… Glucose  Chill out on sweets OR Diabetic?!
Protein  Increased Physical Activity & Pregnancy OR Hypertension & Nephron Disease?!
Pus  Urinary Tract Infection
Blood  Kidney Stones, Infection, Trauma, Anemia ?!
Bile  Liver Disease?!

20. (12) Kidney Dialysis
Used in hospitals when kidneys fail (stop working)
Blood is filtered through mechanical pump + tubing which regulates contents
Causes for Kidney Failure:
Repeated kidney infections
Physical Trauma
Heavy Metal / Chemical poisoning
Low Blood delivery (arteriosclerosis)