Infection and response

• Communicable diseases are spread by pathogens
• Pathogens are microorganisms that cause infectious disease
• Once in the body bacteria can grow very rapidly. They then release harmful chemicals called toxins
• Toxins damage tissues and make us feel ill
• Pathogens can be spread in water (eg.chlorea)
• Two examples of pathogens is bacteria and viruses
• communicable diseases can be spread to people
• non-communicable diseases cannot be spread to other people
• An example of a non communicable disease is coronary heart disease
• Health is the state of physical and mental well being
• People with a defective immune system are much more likely to suffer from infectious diseases
• HPV is extremely common and can be spread through sexual contact and sharing towels. However in some cases it can cause cervical cancer
• The immune system destroys pathogens
• White blood cells can ingest and destroy pathogens
• The white blood cell detects chemicals released from the pathogen and moves towards it. The white blood cell then ingests the pathogen.Then the white blood cell uses enzymes to destroy the pathogens. This process is called phagocytosis
• Another way white blood cells can destroy pathogens is by making antibodies
• Antibodies are protein molecules produced by white blood cells
• Vaccination involves injecting dead or inactive pathogens into the body
• Viruses cannot be killed by antibiotics
• Symtoms of measles include high fever and a red skin rash
• Symptoms of HIV include flu-like symptoms and fatigue. It is transmitted through sexual contact and exchange of fluids between humans