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B5 health and disease - Coggle Diagram

- - - - communicable diseases - diseases which can spread between organisms
      - non communicable diseases - diseases which cannot spread between organisms
    - - different diseases can interact with eachother leading to a spiral of declining health for example
        
        cancer- viruses occupying cells can stimulate cancers, for example the hpv virus can lead to cervical cancer
        
        allergies - allergies eg asthma can be triggered by an immune reaction to a pathogen
        
        mental health - physical problems can negatively impact on an individuals mental health
        
        immune system - a disease which supresses the immune system makes individuals more likely to catch other infectious diseases
  - - - Around 10% of Britain’s annual health budget is required to treat those suffering from diabetes.
      - £9 billion is the total annual healthcare cost for cardiovascular disease.
      - By 2030, it is estimated that the global cost of cardiovascular disease will exceed US$1,000,000,000,000 (~£750 billion).
  - - - four main types of pathogen
        
        virus - viruses are tiny , non living cells that can reproduce rapidly within the body
        They invade host cells and use them to make new virus particles
        once new virus particles made they cause cells to burst
        Cell damage makes us feel ill
        
        Bacteria - small living cells either damange cells directly or by producing toxins
        Bacteria can reproduce rapidly in the appropriate conditions - warm, moist areas with a good supply of oxygen
        The toxins released by bacteria can damage cells and tissues, making us feel ill
        
        Fungi - Fungi are single celled organisms that have a body made up of hyphae
        The hyphae are able to grow and penetrate tissues such as human skin or plant surfaces
        Hyphae produce spores that can spread to other plants and animals
        
        Protists - single celled eukaryotic cells many of which are parasites meaning they live on or inside other organisms
        Often transferred to other host organism by vector such as an insect or mosquito
        They make us feel ill by damaging our tissues
        
        viruses are tiny non living particles that can reproduce rapidly within an organism
        
        they invade host cells
        
        the virus inserts its own dna in the host cell, which is then copied and used to make more viruses
        
        onc ethe new virus particles made, they cause cells to burst this releases the new viruses to invade more cells
        
        the cell damage makes us feel ill
        
        many diseases are caused by viruses, eg
        
        ebola -- ebola virus affects blood vessels causes hemmorrhagic fever
        Ebola spreads through body fluid , can be because of direct contact or contaminated objects eg bedding
        
        measels -
        symptoms include a fever and a rash
        most young children vaccinated for measeles pour ca
        the measeles virus is spread by inhaling droplets from sneezes and coughs
        
        HIV - hiv is spread through sexual contact or exchange of body fluids
        HIV causes aids
        AIDs is the name given to life threatening infections that can happen when persons immune system badly damaged by HIV
        
        Antiretroviral drugs used to treat HIV
        
        How do HIV and AIDS differ?
        
        AIDS (Acquired Immune Deficiency Syndrome) is caused by HIV (Human immunodeficiency virus).
        It is the name given to the life-threatening infections that can occur when a person’s immune system has been badly damaged by HIV.
    - - small living cells that either damage cells directly or by producing toxins
      - can reproduce rapidly in warm, moist conditions which have a good supply of oxygen
      - some examples of bacterial diseases
        
        stomach ulcers - heliobacteria causes stomach ulcers , stomach ulcers are stored in the lining of the stomach. They can eventually lead to cancers
        Spread rhrough eating or drinking something contaminated
        
        Tubercolosis - spreads in water droplets in the air from coughs of infected people
        causes serious damage to lungs
        
        bacteria that is present in contaminated water causes cholera
        The bacteria releases toxins that causes severe diarrhoea which results in dehydration
    - - fungi are unicellular that each have bodies made up of hyphae - thread like structures
        
        hyphae can grow and penetrate tissues such as human skin or the surface of plants
        Hyphae produces spores which can spread to other plants,animals
        
        cholera ash dieback - example of a fungal disease, the spores of this fungus can spread over long distances in the wind
        
        it causes leaf loss and lesions on the bark of ash trees and can kill the trees
    - - protists are single celled eukaryotic organisms
        
        lots of protists are parasites this means they live on or inside other organisms
        
        theyre transferred to host from a vector such as insect or mosquiito
        an example of a disease caused by a protist is
        
        malaria - malaria is spread by the female mosquito, if a mosquito is carrying malaria then it transfers the infection into a persons blood stream whenit bites them
        
        malaria leads to recurring and severe fevers which can cause death
    - - the spread of infections can be prevented by being hygienic , isolating infected individuals by protecting against vectors and vaccination
        
        identifying infection - a method such as dna testing which allows doctors to identify the antigen can help them work out who is infected they may also be able to do this by visual inspection
        
        isolation - by isolating infected individuals we prevent contac t w other organisms which stops the infection spreading
        
        vaccination can make people immune to infection, more individuals vaccinated less likely disease is to spread
        
        disease vectors - some protist diseases are carried by vectors
        A
        
        a vector is an organism that carries pathogens without being infected
        
        eg can protest against mosquitos carrying malaria with mosquito nets
        
        Malaria is spread by vectors, such as mosquitos. How can one stop malaria spreading?
        
        We can stop malaria from spreading by preventing mosquitoes from breeding and using mosquito nets to avoid being bitten.
    - - dead or inactive form of a pathogen is injected into the blood.
        
        2
        
        White blood cells recognise that the antigens are foreign and produce antibodies against them.
        
        3
        
        Some of the white blood cells remain in the blood as memory cells.
        
        4
        
        If the same pathogen invades the body again, the memory cells recognise the pathogen and can produce more antibodies more quickly.
        
        5
        
        The pathogen is destroyed by the immune system before it can cause illness.
    - - What are the characteristics of viruses, like the one that causes measles?
        
        very small, reproduce rapidly, invade host cells
  - - - water - some pathogens contaminate water supplies . pathogens can infect organisms which drink this contaminated water - cholera is spread this way
      - Body fluids - Ebola and HIV are spread through direct contact with someone elses body fluids eg blood
      - Sex - diseases which are spread through sexual contact called stis
        Physical barriers eg condoms effective at stopping stis
        chlamydia is bacterial infection which causes infertility has no other symptoms so easily spreads
        
        anti biotics not a way of stopping spread of hiv
      - air - some pathogens also released into the air in tiny droplets when an organism coughs or sneezes, these droplets can be inhaled by other organisms
        Tuberculosis bacteria are spread in this way
      - orally - by mouth - helico bacteria which causes stomach ulcers is spread through oral transmission of bacteria from vomit or faeces
      - vector - malaria is a protist that is spread by an animal vector eg mosquitos
- - - - life style - for example an unblanced diet or lack of excersise
      - susbtances - substances can be in both individuals body and environment eg chemical inhaled when smoking or consuming alcohol
    - - scientists must look at links to make sure the risk factor is whats causing the disease and not something else altogether
        finding the casual mechanism is the way to prove the link
      - example of such mechanisms
        
        brain damage in babies - excessive alcholol consumption in durning pregnancy is proven risk factor for brain damage in babies
        
        cancer - exposure to ionising radiation is a proven risk factor for cancer
        Unbalanced diet , smoking, excessive alcholol consumpt also risk factors
        
        low birth weight of babies - smokig during pregnancy
        
        Lung disease - smoking proven risk factor
        
        obesity - proven risk factor for type 2 diabetes
        
        cardiovascular disease - poor diet, smoking, lack of excerise
        
        Liver brain damage- excessive alcholol intake
  - - - lifestyle - smoking, obesity and uv exposure
      - genetics - for some cancers , increased risk of cancer can be inherited from parents eg some genes shown to cause increased susceptibility to some cancers
    - - bmi - persons weight/height squared
        
        healthy bmi is between 18.5 -30
      - waist hip ratio measuring distance around persons hips and waist
      - for men w/h r more than 1 is obese
      - for women whr more than 0.85 obese
  - - - n the extreme case of heart failure, patients may require a donor heart to be transplanted. Immediate transplantation is not always possible. This means that patients can be kept alive using artificial hearts whilst they wait for a donor heart.
        
        benefits of artificial hearts
        
        can be used to provide heart with some rest so it can recover
        
        Artificial hearts are unlikely to be rejected by the patient’s immune system, so immunosuppressant drugs are unnecessary.
        
        drawbacks of artificial hearts
        
        can result in long and expensive stays in the hospital
        
        they can cause blood clotting which could lead to a stroke
    - - Lifestyle changes are necessary in addition to treatment. The two common treatments for coronary heart disease are:
        
        statins
        
        statins are drugs that can be taken to decrease blood chloresterol levels which decreases rate at which fat builds up
        
        as with most materials statins can have side effects
        
        stents
        
        stents are inserted to keep coronary arteries open
        
        drugs must be taken to prevent blood clotting on stent
    - - advantages and disadvantages of each teatment
        
        drugs - often cheap to buy and dnont requidrugsre surgert
        
        often cheap to buy, dont require surgery
        
        may have side effects and patient has to remember to take them
        
        mechanical devices
        
        used in cases when donor not available
        
        require a power supply may eventually wear out and need replacing
        
        transplants
        
        succesfully transplanted organs wont wear down and will function like normal organ
        
        disadvantages: Require a suitable donor and immunosuppressants, which can increase the risk of the patient getting another disease.
      - Name the drugs used to decrease blood cholesterol levels:
- - - - mucus and cilia (physical)
        
        mucus is produced in the resppiratory system and traps the particles and bacteria entering our airways
        
        there are cells in our airways that have tiny hairs called cillia which waft the mucus back of throat to be swallowed
      - stomach acid - chemical - glands in the stomach will produce hydrochloric acid which destroys any pathogens entering the stomach
      - tears - chemical
        
        tears contain enzymes called iysozymes which destroy any pathogens that make contact with our eye
      - skin - physical - skin is a waterproof barrierpathogens cannot pass through
        
        good bacteria live permanently on our skin, covering the surface and preventing pathogens from growing on our skin
    - - if a pathogen passes the non specific defences, the immune system is activated
      - the immune system is made up of dif white blood cells which have different functions
        
        anti bodies - white blood cells recognise foreign antigens on surface of pathogens and produce protein molecules called antibodies
        
        antibodies are specific to a particular pathogen
        
        antibodies
        
        whiteblood cells produce antibodies to defend against pathogens
        
        antigens - antigens are protiens found on the surface of cells
        
        white blood cells can recog foreign antigens on surface of pathogen and produce protein molecules called antibodies
        
        complementary shape - antibodies have a comp shape to antigen and lock onto pathogen
        
        this causes the microorganisms to cluster allowing other white blood cells to come ingest them
        
        anti toxins
        
        some bacteria produce toxins that can damage cells and tissues, the immune system responds to this by producing anti toxins
        
        anti toxins neutralise the toxins released by bacteria and prevent them from causing any harm
        
        phagocytes
        
        a whiteblood cell that finds the pathogen and engulfs it by changing shape
        
        the white blood cell absorbs and digests the pathogen, destroying it
    - - protected by a non specific defence
        
        starts with goblet cells in the lining of our respiratory system producing mucus
        
        mucus is a sticky substsance that traps particles and bacteria entering our airways
        
        cells lining the airways have tiny hairs called cillia which sweep mucus to the back
  - - - vaccination
        
        vaccination is main tech used for helping the immune system rec and destroy pathogens
        
        immunising a large population will make it very hard for pathogen to spread
        
        process of vaccination
        
        inject a dead pathogen - a vaccination injects a dead or inactive form of pathogen into blood
        
        immune system recognition - immune system recognises foreign antigen produce antibodies against them
        
        some of these whiteblood cells called lymphocytes stay in blood as memory cells,
        if same pathogen invades again, lymphocytes can produce antibodies faster and produce more antibodies
        this means antibody conc stays in blood longer
        
        next time pathogen infects the vaccinated person, the immune system will destroy it before it can cause illness
        
        making a pop immune - herd immunity
      - Antibiotics
        
        antibiotics such as penicilin are drugs developed to cure infections caused by bacteria .
        Some antibiotics work by destroying cell wall of bacteria so they cant replicate
        
        antibiotics are specific - specific antibiotics are prescibed by medical doctors for diseases
        the use of antibiotics has greatly reduced num of deaths form infectious diseases
        
        antibiotics dont affect viruses - antibiotics dont affect viruses because virus stay in the host cell and arent living cells
      - drug discovery and testing
        
        in past most drugs were extracted from plants and microorganisms, nowadays drugs are synthesised by chemists in pharmaceutical industry
        
        but the ingredients of these drugs may be chemicals extracted from plants
        
        past
        
        the heart drug digitalis orginates from foxgloves - a plant - first used 200 years ago by william withering
        
        painkiller aspirin from willow trees
        
        alexander fleming discovered the antibiotic penicillin made from the penicillium mould
        
        developing new drugs
        
        antiseptics
        
        antiseptics are chemicals which are applied to exposed areas such as cuts or scrapes to prevent rather than treat infection from pathogens
        
        antibiotics
        
        scientists are alwats trialling new antibiotics for when strains of resistant bacteria appear
        
        pain killers
        
        used to relieve pain caused by infection
        
        they do not cure diseases or kill pathogens but they do relieve the symptoms
        
        aspirin is an example of a pain killer
        
        antiviral drugs - viruses are found inside cells this means its hard to desrroy them without damaging cells tissues and body cels
        
        antiviral drugs used to treat viral infections
        
        drug testing
        
        new medical drugs have to be trialled before being used this is to check theyre safe and effective
        
        this testing can take many years nad the drugs are tested on three main criteria
        
        toxicity - is the drug safe
        
        dose - how much of the drug is needed
        
        efficacy - does the drug work
        
        drug testing in labratories
        
        Preclinical testing
        
        scientists carry out testing on human cells and tissues grown in the lab
        
        scientists also carry out early stage testing on animals
        
        this is useful because it shows how harming a drug is to cells
        
        in the uk new medicines have to undergo tests on two different live mammals
        
        clinical testing
        
        clinical trials test drugs on healthy volunteers to check that theyre safe - ususally use low doses of thr drug
        
        if a drug is found to be safe at low doses there are more clinical trials to work out optimum dose for the drug
        
        Clinical tests are usually double-blind trials. This means that some patients are given the drug, and some are given a placebo (which is an alternative that does not contain any of the drug)
        
        In a double-blind trial, all the conditions are kept identical across the two groups so that only the drug has an impact on a patient’s health.
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