second line of defence Flashcards
what is the second line of defence
the nonspecific/innate response = body tries to kill any pathogens that have entered and tries stop movement around the body
what is localised defence
involves inflammation and phagocytosis which localises any break in the barrier and destroys invading pathogens
what are the symptoms of inflammation
1) pain
2) redness
3) heat
4) swelling
what are the functions of inflammation
1) destroy cause of infection
2) limit effects on the body by confining infection to small area
3) replace and repair damaged tissue
outline phagocytosis
1) once a pathogen enters the body there is an increase in the diameter and permeability of the blood vessels causing increased blood flow
2) phagocytes ingest microbe by endocytosis forming a phagosome
3) fusion of the phagosome with the lysosome to form a phagolysosome
4) digestion of ingested microbe by enzymes
5) discharge pf waste materials by exocytosis
what is pus
an abscess containing dead phagocytes, damaged cells and bodily fluids
what are the two types of non-specific white blood cells and where are they produced
1) neutrophils and macrophages produced in the bone marrow
what is a neutrophil
a white blood cells which engulfs and destroys pathogens
1) multilobed nucleus
2) short lived and tend to die after engulfing bacteria
what is a macrophage
a white blood cell which engulf pathogens and then presents its antigen on their surface
1) long-lived
2) settle in the lymph nodes of the spleen and kidney
3) stimulate the specific immune response
briefly outline the non-specific response
1) phagocytes (neutrophils and macrophages) recognise a pathogen due to the specific antigen of the bacteria being foreign
2) cell membrane of the phagocyte will move inwards and pathogen engulfed
3) pathogen held in a vesicle
4_ lysosomes fuse with vesicle and enzymes released
5) neutrophils digest the pathogen by hydrolysis and kill it
6) macrophages partially digest it and present the antigens on cell surface
