1. Getting rid of metabolic wastes!
The Excretory System
Getting rid of metabolic wastes!
Brainpop video

2. Excretory System: sugar O2 nutrients
Function: Removal of metabolic waste products (ex. Water, CO2, salts, and urea) from an organism
B. Comparing Multicellular & Unicellular Organisms
Life Process : excretion
Cell Organelle(s): vacuole, cell membrane (Wastes and CO2 diffuse out of cells) O2
sugar
nutrients
CO2
urea

3. C. Excretory organs 1. LUNGS: Rids body of CO2 2.LIVER
Recycling of red blood cells, production of urea
Urea is made from the breakdown of proteins (amino acids)
Detoxification- Chemical poisons made harmless
3. SKIN: largest gland
contains sweat glands & regulates
body temperature through perspiration
Rids body of excess water, salt
(SWEAT), and some urea

4. 4. The Urinary (excretory) System: (Organ & Functions)
Kidneys (renal infers to anything having to do with the kidney):
filter wastes out of blood to make
urine
maintain water balance & blood pH
b) Ureters: tubes that carry urine to the
bladder
c) urinary bladder: Stores urine
d) urethra: tube where urine exits the
body

5. Kidney Structure
Renal Artery: Blood carrying wastes enters the kidneys
Renal Vein: “clean” blood (no wastes) leaves the kidneys to re-circulate around the body
Renal Cortex: Outer portion
Renal Medulla: “Corn” shaped inner portion
Nephrons: Functional unit of the kidneys!
Lie between cortex and medulla – there are Millions of them
filter the blood, return useful substances to the blood and collect urine.

6. Structure of the Kidneys
Section 38-3
Kidney
Nephron
Cortex
Medulla
Renal artery
Renal vein
Ureter
To the bladder
Bowman’s capsule
Glomerulus
Capillaries
Collecting duct
To the ureter
Loop of Henle
Artery
Vein

7. D. SYSTEMS WORKING WITH SYSTEMS TO MAINTAIN HOMEOSTASIS
The excretory system works with the:
1. Circulatory system: Describe relationship : the blood carries (transports) wastes to the kidneys to be removed; it returns the cleaned blood back to the body
2. Respiratory system: Describe relationship :the lungs excrete CO2 - one of the waste products of cell respiration

8. E. Excretory Homeostasis Disorders
Gout: Caused by deposits of uric acid in joints. Suffer from stiffness and pain in joints. Common with high protein diets.
2. Kidney Stones: caused by a calcium buildup in kidneys due to improper diet. Painful when in the ureter. May need surgery if stone is too large.
3. Cirrhosis: Occurs when too much alcohol is consumed. Liver needs to work extra hard to metabolize alcohol. By products of alcohol (fats) accumulate in liver which causes scarring. Liver may shut down and homeostasis can no longer be maintained

9. Blood in tubing flows through dialysis fluid
 Kidney Dialysis
Blood in tubing flows through dialysis fluid
Blood pump
Vein
Artery
Shunt
Used dialysis fluid
Air detector
Dialysis machine
Fresh dialysis fluid
Compressed air
Filters (cleans) blood because the kidneys cannot