Diseases Flashcards
Diseases definition
Disease: a pathological condition of body parts or tissues characterised by an identifiable group of signs and symptoms
Pathogen definition
Pathogen: an infectious agent that causes disease
Infectious disease definition
an infectious diseases caused by an infectious agent such as bacterium, virus, protozoan, or fungus that can be passed on to others
Non Infectious disease definition
a disease that is not contagious or spreadable such as diabetes, cancer, chronic lung diseases or heart diseases that can be from genetics, unhealthy diets or physical inactivity
First line of defence
Bodies First Line of Defence: Non-specific barriers (broad, external defence “walls and moats”)
• Skin: effective barrier
• Tears: wash pathogens away contain chemicals that kill them
• Nose, Throat and Mouth: contain mucus that raps pathogens
• Stomach: juices contain pathogen killing pathogens
2nd line of defence
2nd line of defence: Non-specific patrols (broad, internal defence “patrolling soldiers”)
• When pathogens are detected the immune system produces millions of white blood cells, which fight the infection
• Blood vessels near the wound expand, and white blood cells move from the vessels to enter the infected tissues
• Many of these white blood cells are phagocytes, which engulf and destroy bacteria
• The infected tissues may become swollen and painful
3rd line of defence
3rd line of defence: true immune system (specific, acquired immunity “elite trained units”)
• The immune system response attacks specific pathogens using cells and proteins
- T cells are white blood cells that attack and kill harmful bacteria
- B cells are white blood cells that make antibodies
• An antibody is a Y-shaped protein that attaches to a specific foreign substance, known as an antigen
• Bind to the pathogen’s membrane proteins
• Cause pathogen to clump together
• Weaken the pathogen’s membrane
