Title of listening text: How the immune system works?
Website address of text: https://youtu.be/PSRJfaAYkW4?t=18
Written version of the text with 12 highlighted vocabulary items for pre-teaching:
Organs
Bacteria
Personnel
Detect
Variable
Diversity
Trigger
Transmit
Infected
Swelling
Reproduce
Disorders
How does the immune system work?
A mosquito lands on your arm, injects its chemicals into your skin, and begins to feed. You
wouldn’t even know it was there, if not for the red lump that appears, accompanied by a
telltale itch. It’s a nuisance, but that bump is an important signal that you’re protected by
your immune system, your body’s major safeguard against infection, illness, and disease.
This system is a vast network of cells, tissues, and organs that coordinate your body’s
defenses against any threats to your health. Without it, you’d be exposed to billions of
bacteria, viruses, and toxins that could make something as minor as a paper cut or a
seasonal cold fatal.
The immune system relies on millions of defensive white blood cells, also known as
leukocytes, that originate in our bone marrow. These cells migrate into the bloodstream
and the lymphatic system, a network of vessels which helps clear bodily toxins and waste.
Our bodies are teeming with leukocytes: there are between 4,000 and 11,000 in every
microliter of blood.