Science Exam - Immune System

pathogen

disease-causing agent

antigen

micro-organism that causes disease and invades the body

infectious disease

disease that can spread

non-infectious disease

disease that cannot be spread

how diseases spread

contact with infected food/water, coughing, talking, sneezing, through vectors

how to stop diseases

quarantine/isolation, sterilisation, vaccines, disinfectants, pasteurisation, antibodies

first line of defence

innate immune system, non-specific, inherited

physical barriers

protects body and prevents pathogens from entering

examples of physical barriers

intact skin, eyelash, mucus, nasal hair, body hair

chemical barriers

chemically washes away pathogens from body's surface

examples of chemical barriers

stomach acid, tears, mucus, body fluids

second line of defence

fast innate response, non-specific, inherited

inflammation

phagocytes travel through bloodstream to wounded area to protect from infection, and fixes damaged tissue on its way

symptoms of inflammation

redness, soreness, swelling, heat

fever

body heat rises to help fight off infection; weakens or kills pathogen in process

third line of defence

adaptive immune system, specific, learned

b cell

makes antibodies (Y-shaped protein that kills pathogens by latching on to them)

t cell

tells b-cell what type of antibody to create

macrophages

engulf pathogens

memory cells

remembers pathogen, meaning a future encounter with the same pathogen will have a faster and more effective response

primary immune response

initial reaction upon contacting a pathogen

secondary immune response

reaction upon contacting a pathogen a second time; more effective and fast response due to memory cells

natural active immunity

body creates its own antibodies

natural passive immunity

antibodies passed from mother's breast milk into the baby's immune system

artificial active immunity

immunisation or vaccination

artificial passive immunity

injection of antibodies donated from different people

vaccination

treatment with a vaccine to produce immunity against a disease

immunity

body's ability to defend itself against a pathogen, shows less symptoms

herd immunity

95% of a community is vaccinated, protecting immuno-compromised individuals

3 main bacteria shapes

rod, sphere, spiral

ectoparasite

parasite that lives outside its host

endoparasite

parasite that lives inside its host