B5

• 5.1 Describe health


  a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity, as defined by the World Health Organization (WHO)
• 5.2 Describe the difference between communicable and non-communicable diseases

  communicable = a disease caused by pathogens so it can be passed from an infected person to other people

  
  

  non - communicable = not passed from person to person but caused by a problem in the body, such as a fault in genes or lifestyle
• 5.3 Explain why the presence of one disease can lead to a higher susceptibility to other diseases

  one disease could damage the immune system, making it easier for other pathogens to cause disease - the immune system protects the body from communicable diseases.

  
  

  a disease damages the body's natural barriers and defences, allowing pathogens to get into the body more easily

  
  

  a disease stops an organ system from working effectively, making other diseases more likely to occur
• 5.4 Describe a pathogens and name 4

  a disease-causing organism, including viruses, bacteria, fungi and protists
• 5.5 Describe some common infections, including: cholera


  (bacteria) causes diarrhoea
• 5.5 Describe some common infections, including: Tuberculosis (TB)


  (bacteria) infects and damages the lung, causing lung damage and blood speckled mucus after coughing, fever, weight loss
• 5.5 Describe some common infections, including- Chalara ash dieback


  Fungi, causes leaf loss and bark lesions, airborne
• 5.5 Describe some common infections, including: Malaria

  (protists) protists multiply inside red blood cells and liver cells, causing damage to blood and liver. when new protists break out of these cells, it causes fever, weakness and sickness
• 5.5 Describe some common infections, including: HIV


  (virus) destroys white blood cells in the immune system, leading to the onset of AIDS as the immune system cannot protect them from secondary infections
• 5.6 Explain how pathogens are spread and how this spread can be reduced or prevented, including: cholera (bacteria)

  water - after earthquakes, water pipes which carry clean water may break

  
  

  keeping water clean to remove or kill pathogens - good hygeine
• 5.6 Explain how pathogens are spread and how this spread can be reduced or prevented, including: tuberculosis (bacteria)

  airborne - when people sneeze or cough, droplets containing pathogens are sent into the air, where they can survive for months and mix with dust.

  
  

  if people 'catch it, bin it, kill it,' after they sneezed, they would stop the spread of pathogens
• 5.6 Explain how pathogens are spread and how this spread can be reduced or prevented, including: Chalara ash dieback (fungi)

  airborne - can spread in the air as tiny spores. strong winds can carry them over long distances
• 5.6 Explain how pathogens are spread and how this spread can be reduced or prevented, including: malaria (protists)

  animal vectors - carried in blood by mosquitoes who sucked blood from an infected person and injects the protists directly into the blood of the next person it feeds on

  
  

  control the spread of the vector - kill mosquitoes
• how to protect yourself from the ebola virus

  to wear a full body protection, as the virus is present in all bodily fluids of infected people, even after death. it easily enters bodies through broken skin or the eyes, nose and mouth
• 5.8 Explain how sexually transmitted infections (STIs) are spread and how this spread can be reduced or prevented, including:

  a Chlamydia (bacteria)


  spread by contact with sexual fluids (semen or vaginal fluid). Can be passed from a pregnant woman to unborn baby. can also be passed from an infected person to others through blood, such as through sharing needles when injecting drugs

  
  

  Avoiding direct contact with sexual fluids by using a condom as an artificial barrier during sexual intercourse.
• 5.8 Explain how sexually transmitted infections (STIs) are spread and how this spread can be reduced or prevented, including: HIV (virus)

  same stuff

  
  

  screening helps to identify an infection so that people can be treated for the disease and not pass it on to others

  
  

  blood is first screened (checked) to make sure it does not contain HIV particles or other pathogens
• 5.12 Describe how the physical barriers and chemical defences of the human body provide protection from pathogens, including: physical barriers, including mucus, cilia and skin

  skin is very thick and covers most of the body, which pathogens can only cross through wounds or by an animal vector who pierces the skin (physical barrier)
• 5.12 Describe how the physical barriers and chemical defences of the human body provide protection from pathogens: chemical defence, including lysozymes


  lysosomes secreted on the skin are an enzyme that breaks down the cell walls of some types of bacteria (chemical defense)

  
  

  also secreted in tears, saliva and mucus. It helps to protect the thinner surfaces of the body. Mucus is sticky and produced by cells lining many openings, so therefore the pathogens cannot enter the body because they get trapped in it
• 5.12 Describe how the physical barriers and chemical defences of the human body provide protection from pathogens, including: chemical defence like hydrochloric acid

  some cells lining the stomach secrete this, reducing the pH to around 2. many pathogens are destroyed at this acidity
• How do immune systems identify if something inside the body is a cell of the body or has come from outside

  all cell and virus particles have molecules on the outer surface, called antigens, which the immune system uses to work this out
• 5.13 Explain the role of the specific immune system of the human body in defence against disease, including: exposure to pathogen


  pathogens have antigens on their surface that are unique to them
• 5.13 Explain the role of the specific immune system of the human body in defence against disease, including: the antigens trigger an immune response which causes the production of antibodies

  A lymphocyte with an antibody that perfectly fits the antigen is activated
• 5.13 Explain the role of the specific immune system of the human body in defence against disease, including: the antigens also trigger production of memory lymphocytes


  This lymphocyte divides over again to producer clones of identical lymphocytes
• 5.13 Explain the role of the specific immune system of the human body in defence against disease, including: the role of memory lymphocytes in the secondary response to the antigen


  Some of the lymphocytes secrete large amounts of antibodies. The antibodies stick to the antigens and destroy the pathogen. Other lymphocytes remain in the blood as memory lymphocytes, ready to respond immediately if the same antigen ever turns up again, causing a much faster secondary response which stops you from becoming ill
• 5.14 Explain the body's response to immunisation using an inactive

  form of a pathogen


  usually causes little reaction, and will protect against particular diseases for many years
• 5.16 Explain that antibiotics can only be used to treat bacterial infections because they inhibit cell processes in the bacterium but not the host organism.

  Antibiotics can only be used to treat bacterial infections because they inhibit cell processes in the bacterium but not the host organism.
• 5.23 Describe that.... (non-communicable diseases)

  many non-communicable human diseases are caused by the interaction of a number of factors, including cardiovascular diseases, many forms of cancer, some lung and liver diseases and diseases influenced by nutrition
• 5.24 Explain the effect of lifestyle factors on non-communicable diseases at local, national and global levels, including:

  
  

  a exercise and diet on obesity and malnutrition , including the two equations


  BMI = mass (kg)/ (height (m))2 (30+ = obese) and waist : hip ratios

  
  

  obesity = diet which is high in sugars and fats, where large amounts of fat are formed under the skin and around organs. no exercise means that there will be more fat

  
  

  malnutrition = too little/much of a particular nutrient
• 5.24 Explain the effect of lifestyle factors on non-communicable diseases at local, national and global levels, including: alcohol on liver diseases

  ethanol is broken down by the liver and a large amount of ethanol taken over a long period can lead to liver disease
• 5.24 Explain the effect of lifestyle factors on non-communicable diseases at local, national and global levels, including: smoking on cardiovascular diseases

  tobacco smoke substances are absorbed from the lungs into the blood and are transported all over the body. can damage vessels, increase blood pressure, make blood vessels narrower and increase the risk of blood clots forming in blood vessels, which all lead to this disease
• 5.25 Evaluate some different treatments for cardiovascular disease, including:

  
  

  a life-long medication


  help prevent a heart attack or stroke
• 5.24 Explain the effect of lifestyle factors on non-communicable diseases at local, national and global levels, including: surgical procedures

  narrowed blood vessel can be widened by inserting a stent at the narrowest part to hold it up. blocked arteries can be bypassed by inserting other blood vessels so that the heart tissue is supplied with oxygen and nutrients
• 5.24 Explain the effect of lifestyle factors on non-communicable diseases at local, national and global levels, including: lifestyle changes

  to exercise more and give up smoking