Diet & Disease

Nota:

• Type of saturated fat (lipid) required for body functions, also part of cell membrane structure.

1. LDL

   Nota:

   • Low density lipoproteins- carry cholesterol in the blood from liver. Can lead to formation of black clot and chronic heart disease. 
   1. Bad
2. HDL

   Nota:

   • High density lipoproteins- carry cholesterol from the blood to the liver where it is stored. 
   1. Good

1. Plaques

   Nota:

   • Fatty foods and genetic make-up can cause build-up of plaques in arteries
   1. Block arteries

      Nota:

      • Reduces free flow of blood in arteries to heart, if pressure put on it bursts.
      1. Rupture

         Nota:

         • If the person exerts themselves the heart rate increases, and more pressure is put on artery till plaque ruptures and blood clot forms, stopping flow of blood. Adrenalin from pain increases heart rate again.
         1. Oxygen deprivation

            Nota:

            • Areas of body are deprived of oxygen and heart stops beating due to distress signals. Heart muscle cells burst.

1. BMI = mass/height*

Nota:

• Chemical reactions in cells (in cytoplasm)

1. Metabolic Rate

   Nota:

   • Speed at which chemical reactions occur in cells
   1. Affected by:
      1. Gender
      2. Age
      3. Genetic Make-up
      4. Fitness Level
      5. Physical Size
      6. Diet

Nota:

• Micro-organisms that cause disease. An infectious disease is one transmitted from person to person with contact with the pathogen.

1. Viruses

   Nota:

   • HIV, Polio etc..
   1. Differences
2. Bacteria

   Nota:

   • Tuberculosis 
3. Fungi

   Nota:

   • Yeasts and Moulds
4. Protozoa

   Nota:

   • Malaria caused by mosquito saliva
5. Macro-parasite

   Nota:

   • Head lice, tape worm
6. Spread of pathogens
   1. Direct Contact

      Nota:

      • Macro-parasites and protozoa
   2. Indirect Contact

      Nota:

      • Air and contaminated items- bacteria, viruses, fungi...

1. 1870s

   Nota:

   • It wasnt until the 19th century that germs were identified and recognised as a treatable cause of disease.
2. Doctors of the time

   Nota:

   • At the time doctors did not want to admit that hygiene was a problem so ignored Semmelweiss's advice.
3. Calcium Chloride

   Nota:

   • Used calcium chloride as an antiseptic on surfaces

1. 1st line of defence: Skin

   Nota:

   • Acts as a physical barrier against pathogens
2. 2nd line of defence: Blood cells and stomach acid
   1. Blood cells
      1. Platelets

         Nota:

         • Wait in blood for cut so they can form a scab
      2. White Blood Cells

         Nota:

         • Produce anti-toxins to neutralise pathogen
         1. Phagocytes

            Nota:

            • Phagocytosis- Engulf into vacuole to destroy with enzymes
         2. Lymphocytes

            Nota:

            • Produce antibodies that bind to antigens on surface of pathogen. This makes a large clump to be engulfed by phagocytes
      3. Red Blood Cells

         Nota:

         • Large surface area, carry oxygen around body, no nucleus
   2. Stomach Acid

      Nota:

      • The very low pH of our stomach acid means it is very acidic so may kill many pathogens that cannot cope in the high acidity
3. Antibiotics

   Nota:

   • Only for bacteria- drugs that target bacterial infections
   1. MRSA

      Nota:

      • A very resistant strand of Staphylococcus Aureus. 
      1. Mutation

         Nota:

         • Mutation- change in DNA. The original bacterium that is nto resistant mutates till it is resistant, multiplying as the weaker strands are killed off by antibiotics. Then there is a colony of resistant bacteria 
4. Vaccination
   1. Jenner

      Nota:

      • In 1796 Edward Jenner realised milkmaids who came into contact with cowpox were immune to smallpox
   2. Immunity

      Nota:

      • The injection of dead or inactive pathogens of the disease can evoke a response from the body's immune system so they can cope with the virus when they come into contact with it again. It will know the correct antibodies

Nota:

• An experiment/operation performed under sterile conditions. Flame sterilisation is a good idea.

Nota:

• Pandemic- country/world Epidemic- population or community