Identify types of wastes in the body
Describe the organs of the excretory system
Explain how the body removes waste (excretion
process)
City Process
Body Equivalent
Garbage production
Cells produce waste
Garbage collection
Blood collects waste
Sorting & treatment
Organs filter/process waste
Storage
Waste temporarily stored
Disposal
Waste removed (urine, sweat,
breath)
Key Idea: Every cell produces waste
→
must be removed to keep the body alive.
Prevents toxic build up
Gaseous Waste
From: Cellular respiration
Example:
Carbon dioxide (CO₂)
Maintains blood pH
Prevents acidosis
Excess Water & Salts
From: Diet + metabolism
Examples:
Water
Sodium, potassium, chloride
Maintains:
Water balance
Electrolyte balance
Blood pressure
Functions:
Releases sweat (water, salts, small urea)
Regulates temperature
Key Parts:
Sweat glands
→
produce sweat
Sweat pores
→
release sweat
Dermis
→
contains glands, blood vessels, nerves
Sebaceous glands
→
produces oil
EXCRETORY ORGANS
LESSON:
TYPES OF WASTE
NOTES
EXCRETORY SYSTEM
GOALS
BIG IDEA
EXCRETORY SYSTEM = WASTE MANAGEMENT SYSTEM
Nitrogenous Waste
From: Protein & nucleic acid breakdown
Examples:
Ammonia (very toxic)
Urea (converted in liver
→
safer)
Uric acid
S K I N
Removes:
Carbon dioxide (CO₂)
Water vapor
Important:
Helps maintain blood pH balance
L U N G S
Cooling effect
Responsible for sensation
Protection against
bacteria
L I V E R
Functions:
Detoxifies harmful substances
Converts ammonia
→
urea
Removes:
Toxins & drugs
Bilirubin (from RBC breakdown)
K I D N E Y
Location:
On both sides of spine, below ribs
Key Unit:
Nephron (
≈
1 million per kidney)
