Excretion in Humans: The Body’s Cleanup Crew

 

What is Excretion?

• Excretion is the process which the body removes waste products from metabolic reactions, toxic materials and products in excess produced in the body.
• These wastes are produced during normal body activities and must be removed to keep you healthy.

 

Why is Excretion Important?

• If waste products build up in the body, they can become toxic and harm cells.
• Carbon dioxide is an example of a product that can become harmful. Excess carbon dioxide can dissole in water to easily form a solution which is acidic, lowering a cells pH.
• Excretion helps maintain a clean, balanced internal environment.

Think of it like taking out the trash at home: Without regular cleaning, the house (your body) would become unhealthy.

 

Excretory System

What is the excretory system?

• The excretory system is made up of ograns which are specialised for removing excretory products
• The excretory system includes the kidneys and the lungs
• The liver is also very imoportant in the excretion process

 

Organ	What it excretes	What It Does
Lungs	Carbon Dioxide $(CO_2)$	Remove carbon dioxide (produced from aerobic respiration) during exhalation.
Kidneys	Urea, excess water, and ions	Excrete urea, excess water, and ions (produced in liver from excess amino acids) through the urine.

 

Word Equations for Excretion Processes

1. In Lungs (Exhalation): $$\text{Glucose} + \text{Oxygen} \to \text{Carbon Dioxide} + \text{Water} + \text{Energy}$$ Carbon dioxide is a waste product here

2. In Kidneys (Urine Formation):
   Excess water, urea, and ions are filtered out of the blood and form urine.

 

The main parts of the excretory system

 

 

Structure	Description
Ureter	Connects the kidney and the bladder
Urethra	Allows urine to leave the body by connecting to the bladder
Bladder	Stores the urine produced in the kidney
Kidneys	Bean shpaed organ. Mainly filters the blood.