B5- communicable diseases

• What is health

  A state of physical or mental wellbeing
• Factors for good health

  • well balanced diet
  • Getting enough exercise and sleep
  • Access to medical care
• what is disease

  Conditions that cause ill health
• What are communicable diseases

  Infectious diseases that spread from person to person - spread by viruses, bacteria, parasites and fungi
• what can cause ill health

  • poor diet
  • Stress
  • Life situations
• What is tuberculosis and how do pathogens interacts

  A communicable lung disease

  In most people the immune system fights of TB

  Some people have a defective immune system (hiv)

  Defective immune systems are much more likely to suffer from infectious diseases
• HPV - interactions of diseases

  Extremely common and in most cases harmless

  In some cases HPV can cause cervical cancer

  HPV infects cells of cervix
• Interaction of diseases - allergies

  disease can be triggered by immune system (allergies)

  The body Is infected with a pathogen which the immune system fights of but they are left with an allergy
• Interaction of diseases - mental illness

  Can be triggered by physical illness

  People with arthritis find it difficult to move and live a normal life

  This can make them feel isolated and depressed
• what are white blood cells

  Cells that defend against infection and pathogenic microorganisms
• What are pathogens

  Microorganisms that cause infectious diseases
• What are the four types of pathogens

  Bacteria, viruses, protists, fungi
• How do bacteria cause illness

  • once inside they reproduce rapidly
  • Then releases harmful toxins
  • Toxins damage tissues and make us feel ill
• how do virus’ cause illness

  • cannot reproduce themselves, only in a host cell
  • the virus invades the host cell
  • it reproduces in the host cell
  • thid damages the cell
  • when it leaves the cell it bursts open and dies
• how are pathogens spread

  • air (water droplets) - influenza
  • Water - cholera
  • Direct contact - hiv
• How can we reduce the spread of pathogens

  • basic hygiene - washing hand before eating
  • Providing people with clean drinking water - uk water contains chlorine to kill microbes
  • Using a condom during sexual intercourse
  • Isolation of patient with highly infectious diseases
  • vaccination
• What is a virus

  A pathogen which cannot be killed by anti biotics
• What are the symptoms of measles

  • fever
  • Red skin rash
• how does measles spread

  droplets - coughs and sneezes
• complicatiosn with measles

  Can cause damage to respiratory system and Brain
• how is measles prevented

  children vaccinated
• hiv stages

  • flu-like illness
  • virus attacks cells of immune system
  • immune system becomes damaged
  • Eventually stops fighting off other, minor infections
  • Unable to fight off cancerous cells
  • Can contract infections like tuberculosis and cancer
  • Described as late stage hiv/aids - fatal
• Hiv treatment

  Antiretroviral drugs - stop virus multiplying in cells- Doesn’t damage immune system - do not go on to develop aids- live normal life expectancy
• problem with antiretroviral drugs

  Not a cure for aids, must take drugs for rest of life
• how is hiv transmitted

  exchange of fluid - sexual contact and blood from shared needles
• What are bacterial diseases

  Communicable diseases spread by pathogens

  Can be killed by antibiotics
• What causes salmonella

  Bacteria spread from ingesting infected food prepared in unhygienic conditions
• how does salmonella bacteria cause infaction

  bacteria secrete toxins
• Symptoms of salmonella

  • fever
  • Abdominal cramps
  • vomitting
  • Diarrhoea
• How is salmonella prevented

  All uk poultry are vaccinated to prevent spread of disease
• what is gonorrhoea (bacterial)

  sexually transmitted disease

  symptoms of thick yellow/green discharge from penis/vagina

  pain when urinating
• Problems with treating gonorrhoeal

  Used to be treated using penicillin but now antibiotic resistant strains are common
• How is gonorrhoea prevented

  • using condom during sexual intercourse to stop spread of bacteria
  • People who have unprotected sex tested for gonorrhoea- can be treated by antibiotics to stop spread
• What is a malaria (protists)

  • communicable disease
  • Can lead to repeated bouts of fever
  • Can be fatal
• lifecycle of malaria

  • the infected person is bitten by a mosquito and malaria pathogen is spread to the mosquito
  • Mosquito bites a different person and passes pathogen to them (mosquito is a vector as it carries the pathogen)
• ways to prevent spread of malaria

  • stop vector from breeding - mosquitoes breed in still water- drain areas of still water or spray with insecticide
  • prevent mosquitos from biting humans - mosquito nets
• Skin - defence system

  • protective layer covering body
  • Outer layer consists of dead cells that are difficult for pathogens to penetrtae
  • Produces sebum which kills bacteria
  • Skin scabs over
• nose - defence system

  • contains hair and mucus to trap pathogens
• lungs - defence system

  • trachea and bronchi covered in cilia
  • Cilia are covered in mucus to trap pathogens
  • cilia waft mucus up to throat where it is swallowed into stomach
• Stomach - defence system

  • contains hydrochloric acid to kill pathogens before they can get to digestive system