1. Unit 1-8 Notes Mr. Hefti – Pulaski Biology
The Excretory System
Unit 1-8 Notes
Mr. Hefti –
Pulaski Biology

2. Excretory System Fun Facts
The bladder is as big as your brain.
The kidneys are each half the size of your bladder.
An estimated 11,000 gallons of fluid pass through the bladder and out through the urethra in the average person's lifetime.
The ureter is the size of a spaghetti noodle.
As you urinate, your bladder starts to shrink immediately only to grow larger when it refills with urine at a later time.
The kidneys have over 1,000,000 nephrons (things that filter the blood) inside of them.
Kidney stones can be the size of a golf ball.
Water forms 95% of the urine.
The skin eliminates numerous toxins from the body.

3. Urination is a method of getting rid of wastes!
Kidneys (light brown)
Renal artery (red)
Renal vein (blue)
Ureter (white)
Urinary bladder (yellow) A
Urethra (light blue)
Urination is a method of getting rid of wastes!

4. There are millions of these in each kidney!
Renal tubule
(yellow)
Renal artery (red)
Capillaries (red to blue) B
Renal vein (blue)
Collecting duct (yellow)
There are millions of these in each kidney!

5. C Key – Skin 1 = epidermis (tan) 2-5 = dermis (as is)
6 = pore (light blue)
7 = sweat gland
(dark green)
8 = sebaceous gland (light green)
9 = muscle (red)
10 = hair (as is)
11 = endodermis (white)
12 = hair follicle (purple) C
The skin gets rid of wastes, too!

6. Make connections…
Which organelle is responsible for getting rid of wastes?
Cell membrane
How is the excretory system linked to the digestive, respiratory and circulatory systems?
The excretion of wastes is necessary for any organism’s survival!