3.5- Nonspecific Body defences Flashcards
What is Immunity
The ability of the body to resist infection by a pathogen or to destroy the organism if it succeeds in invading the body.
What is non specific
Doesnt target specefic pathogens
What is specefic
Targets certain pathogens
Name the 3 Bodys line of defences
Physical and chemical defences
The infammatory Response
Phagocytosis
Describe a physical defence
Skin epithetial cells act as a barrier.
Mucous membrane of digestive tract made of closly packed Ephitial cells which act as a barrier
Describe a chemical defence
Skin and stomach the acid secretions kill pathogens
Mucus in the lungs- Traps pathogens and cillia cells which moves them away.
What is a pathogen
Any organism that can cause disease
STAGE 1
Process of Inflammation
After mast cells are activated they relase histmanine
STAGE 2
Process of Inflammation
Histamine causes blood vessels to dilate and become more permmeable
STAGE 3 - Halfway
Process of Inflammation
This cause Vasodilation of blood vessels so the injured area becomes red and inflamed
STAGE 4
Process of Inflammation
The streched capillary walls become more permeable and leak fluid into neighbouring tissues
STAGE 5
Process of Inflammation
Blood flow increases which leads to an accumulation of phagocytes which englulf pathogens by phagocytosis
**STAGE 6 **FINAL STAGE
Process of Inflammation
Blood clotting factors arrive of site of injury.
What cells are activated after an injury and what do they release
Mast cells activate and they release histamine
STAGE 1
Describe Phagocytosis
Phagocyte recognises pathogen
