This introduction covers Your Body's Security System within Human Defense Systems - Non-specific for GCSE Biology. Physical and chemical barriers, white blood cell responses, inflammatory response It is section 1 of 16 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.
Your Body's Security System
Imagine your body as a fortress under constant attack from invisible invaders. Every second of every day, countless pathogens — bacteria, viruses, fungi, and other microorganisms — try to breach your defences and establish infections. But your body isn't defenceless. You have a security system that works 24/7 to keep you healthy.
This security system has two main layers. The first layer consists of physical and chemical barriers designed to keep pathogens out entirely. If they break through, a second layer of white blood cells springs into action. This is your non-specific (innate) immune system — it responds the same way to any pathogen, without needing to recognise what type it is.
Practice questions for Human Defense Systems - Non-specific
Which part of the body acts as the main physical barrier to prevent pathogens entering?
Explain how mucus and cilia in the airways protect against pathogens.