B2 - Keeping Healthy

• Pathogens are microbes that cause communicable diseases
• Communicable diseases are diseases that can spread via human interaction or vectors such as mosquitos, e.g - Malaria, Atheletes Foot
• Non- Communicable diseases are diseases that cannot be spread by vectors and are caused by the patients lifestyle choices or genetic material e.g - CHD or Cancer
• Vectors are organisms that carry pathogens from one host to another, they do not get infected themselves but act as carriers.
• There are 4 types of pathogens -

  Bacteria - very small cells that reproduce rapidly. They produce toxins that damage cells and tissues

  Viruses - Not cells. once inside affected organisms cells, will replicate themselves until the cells burst which releases the virus.

  Protists - Eukaryotic cells which are usually single - celled and parasites

  Fungi - Some single - celled, some have a thread - like structure (Hyphae) which can grow to penetrate surfaces of both humans and plants. Also produce spores which can spread via air to furthur spread the disease
• Antibiotics kill bacteria by disrupting their metabolism or DNA
• The most important part of the immune system is the white blood cells as they can engulf them, produce antibodies, produce antitoxins and produce memory cells
• Phagocytes have a flexible membrane with enzymes and they engulf and destroy the pathogens
• Lymphocytes create antibodies that bind to antigens and destroy them
• Memory cells are the cells that are activated by the antigen and are able to produce antibodies from the past infection, making it faster to kill the pathogen and give the body a faster recovery time
• Antibodies latch onto the antigens of the pathogens and have to be specific to the antigen so it takes time for the correct one to be created but the memory cells retain the past antibodies so if a reinfection comes, the pathogens will be destroyed more quickly
• Response to vaccines:

  1. The vaccine contains inactive/dead pathogens that enters the blood through injection
  2. Lymphocytes makes antibodies against the pathogen's antigens
  3. Phagocytes engulf the pathogen which destroys them
  4. Memory cells which are created stay in the bloood, creating immunity to the certain pathogen so if the actual pathogen does attack, the body will be able to respond fast
• Herd Immunity occurs when enough people within a population have received a vaccine to stop the spread of a disease.
• Immunisation is when an individual has been given a vaccine to prevent themselves getting ill from a particular disease.
• Vaccination is when an individual receives a weaker form of a disease or dead bacteria/virus to stimulate their immune response without causing illness.
• Vaccination is when a large number of individuals receive a vaccine at once to protect the whole community from a disease.
• Vaccination is important because it stops the spread of diseases as well as protecting those who cannot receive the vaccine due to medical reasons or age restrictions
• Infectious Diseases can be caused by bacteria, viruses, fungi and parasites
• A vaccine can contain either weakened forms of the pathogen (live attenuated) or parts of the pathogen (killed).
• Bacteria can become resistant to antibiotics over time
• Advantages to vaccines:

  • Can wipe out diseases such as small pox
  • Stopes a large outbreak of disease
  • Can protect those who can't have the vaccine if the majority are protected
  • Reduces cost of trreatment for disease
• Disadvantages to vaccines:

  • Can cause other illneses/side effects from the vaccine
  • Can have ingrediants that someone is allergic to or cannot have due to religion/ethics
  • It can only prevent not cure
  • Cost of vaccination programs are very expensive
• CHD affects the blood vessels and heart by blocking the arteries by plague build-up which stops blood flow and can cause heart strokes or a heart attack
• The risk factors for CHD are:

  • Smoking
  • Alcohol
  • Lack of exercise
  • Diet high in sugar, fat or salt
  • Being overweight or obese
  • High blood cholesterol
  • High blood pressure
  • Genes