B3: infection and response Flashcards
(45 cards)
Pathogens
- Microorganisms that enter the body and communicable cause disease that spread to easily
- Animals and plants can be infected
- release toxins and attack cells
Bacteria
- Very small Cells
- Reproduce rapidly inside your body
- Produce toxins - making you ill
- Damage your cells and tissues
Viruses
- Are NOT cells
- Reproduce rapidly
- Live inside your cells and replicate themselves
- Take I’ve hosting cells
Protists
- Eukaryotes cell
- Some are parasites
- Often transferred to the organism by a vector which doesn’t get the disease it’s self e.g. mosquito
Fungi
- Grows and penetrates the human skin and surface of plants causing disease
- Spread by spores
How are pathogens spread?
- Water - picked up by drinking or bathing in dirty water e.g. cholera
- Air - carried in the air and can be breathed in , some are carried in air droplets produce when you cough or sneeze
- Direct contact - picked up by touching contaminated surfaces , including the skin
Measles
- Viral disease
- Spread by droplets from and infected persons sneeze or cough
- Develop red skin rash and signs of fever
- Can be fatal if there are complications - pneumonia or encephalitis
- Most people are vaccinated
HIV
- Is a virus
- Spread by sexual contact or exchanging body fluids such as blood
- Cause flu-like symptoms for a few weeks then the person doesn’t experience any symptoms for many years - during this time HIV can be controlled with antiretroviral drugs stopping the virus from replicating
- Attached immune cells
- Immune System is badly damaged and can’t fight off infections or cancers - late stage HIV or AIDS
TMV(tobacco mosaic virus)
- virus
- affects plants
- causes mosaic pattern on leaves of the plants - parts of of the leaves become discoloured
- discolouration means the plant can’t carry out photosynthesis ad well
- virus affects growth
Rose black spot
- Fungal diseases
- Causes purple or black spots to develop of the leaves of rose plants
- leaves can turn yellow and drop off
- less photosynthesis can happen - plants done grow very well
- spreads through the environment in water or by wind
- treated by using fungicides and by striping the plant of it’s affected leaves
Malaria
- Disease caused by a protist
- part of the protist life cycle takes place in the mosquitos- the vectors
- every time the mosquito feeds on another animals it infects a it by inspecting the protist into the animals blood vessels
- causes repeating episodes of fever
- spread can be reduced by stopping mosquitos from breeding - protected by using insecticides and mosquito nets
Salmonella
- Bacterial disease
- Causes food poisoning
- Infected people can suffer from fever , stomach cramps , vomiting and diarrhoea
- Symptoms are caused by toxins that the bacteria produce
- You can get it but eating contaminated food
Gonorrhoea
- Bacterial disease
- Sexually transmitted disease
- Passed in by sexual contact
- Symptoms are Pain when they urinate and yellow or green discharge from vagina or the penis
- Originally treated with an antibiotic but had become resistant to it
- To prevent spread people can be treated with antibiotics and should use Barrier methods of contraption
Reduce or prevention on disease
Being hygienic - simple hygiene measures, washing hands before preparing food etc
Destroying vectors - by getting rid of organisms that spread the diseases you can prevent the disease from spreading
Isolating infected individuals
Vaccination - the person can not develop the infection and then pass it on to someone else
Body’s Defense system- Skin
- Acts as a Barrier to pathogens
- Secretes antimicrobial substances which kill pathogens
- Skin looses layers and removed the bacteria with them
Body’s Defense system- Nose
•Hairs and mucus in your nose trap particles that could contain pathogens
Body’s Defense system- Teaches and bronchi
•Secrete mucus to trap pathogens
Body’s Defense system- Trachea
•Lined with cilia which waft the mucus up to the back of the throat where it can be swallowed
Body’s Defense system- stomach
- Produces hydrochloric acid
* Kills pathogens that make it that far from the mouth
Immune system
- Kicks in to destroy pathogens that make it into your body
* Most important part of the immune system is the white blood cells
White blood cells
•Travel around in your blood patrolling for microbes
•When they come across the microbe they have three lines of attack
-Consuming
-Producing antibodies
-Producing antitoxins
White blood cells three lines of attack
•Consuming the pathogen
-WBC engulf foreign Cells and digest them - phagocytosis
•Producing antibodies
-Every invading pathogen has antigens on its surface so the WBC will start to produce proteins called antibodies to lock into the invading cells so that they can be found and destroyed by they WBC
-The antibodies produced are specific to the antigen
Produces rapidly
- memory cells remember the pathogen if the person is infected again and will be immune to that pathogen
•producing antitoxins
- contract toxins produced by the invading bacteria
Vaccination
- Injecting small amounts of dead or inactive or weakened pathogens which carry antigens which causes your body to produce antibodies to attack them
- So if live pathogens appears after that WBC can rapidly mass produce antibodies to kill the pathogens instead of taking days to learn how to deal with it
Pros of vaccination
- Controls lots of communicable diseases that were once common
- Epidemics can be prevented if a large percentage of the population is vaccinated
