Infection & ResponseDefinitions

Key Definitions

Part of Human Defense Systems - Non-specific · GCSE GCSE Biology revision

This definitions covers Key Definitions within Human Defense Systems - Non-specific for GCSE Biology. Physical and chemical barriers, white blood cell responses, inflammatory response It is section 10 of 16 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.

Topic position

Section 10 of 16

Practice

21 questions

Recall

22 flashcards

Key Definitions

Non-specific immunity: The body's first and second lines of defence that respond the same way to all pathogens, regardless of type, without requiring previous exposure.

Phagocyte: A type of white blood cell that can engulf and digest pathogens by the process of phagocytosis.

Phagocytosis: The process by which a phagocyte detects a pathogen, surrounds it with its cell membrane, takes it inside the cell, and destroys it using digestive enzymes.

Lysozyme: An antimicrobial enzyme found in tears, saliva, and mucus that destroys bacterial cell walls.

Mucus: A sticky secretion produced by cells lining the respiratory and digestive tracts. Traps pathogens, dust, and debris and prevents them from reaching deeper tissues.

Cilia: Microscopic hair-like projections on cells lining the airways. Beat rhythmically to sweep mucus (with trapped pathogens) upward and away from the lungs.

Keep building this topic

Read this section alongside the surrounding pages in Human Defense Systems - Non-specific. That gives you the full topic sequence instead of a single isolated revision point.

Why Physical and Chemical Barriers Are the First Priority Common Misconceptions Your Body's Security System Key Facts: Non-Specific Defences

Practice Questions for Human Defense Systems - Non-specific

Which part of the body acts as the main physical barrier to prevent pathogens entering?

A. The skin
B. The lungs
C. The heart
D. The brain

1 markfoundation

Explain how mucus and cilia in the airways protect against pathogens.

3 marksstandard

Quick Recall Flashcards

What is phagocytosis?

The process by which white blood cells (phagocytes) engulf and digest pathogens or foreign particles.

What is sebum?

An oily substance produced by sebaceous glands in the skin that creates an acidic environment on the skin surface, inhibiting bacterial and fungal growth.

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Why Physical and Chemical Barriers Are the First Priority

Common Misconceptions