Chapter 3 - Infection And Response Flashcards
What are pathogens
Pathogens are microorganisms that into the body and cause disease
What type of disease do they cause
Because communicable diseases which are infectious
Both plants and animals can be infected by pathogens
What are the different types of pathogens
Bacteria
Viruses
Protists
Fungi
How does bacteria make you feel ill
They can make you feel ill by producing toxins that damage your cells and tissue
How do you viruses make you feel ill
They can reproduce rapidly inside your body. They live inside your cells and replicate themselves using the cells machinery to produce many copies of themselves. The cell will usually burst releasing all the new viruses.
This cell damage is what makes you feel ill
What are protists and what did they do
There are lots of different types of protests. They are all eukaryotes and most of them are single celled
Some protests are parasites. Parasites live on the inside other organisms and can cause them damage. They are often transfer to the organism by vector which doesn’t get the disease itself e.g. an insect Carries the protest.
What is fungi?
What does it do?
Some fungi are single celled. Others have a body which is made up of hyphae which is a thread like structure.
These hyphae can grow and penetrate human skin and the surface of plants causing diseases
What are the different ways that pathogens can be spread?
Water-some pathogens can be picked up by drinking or bathing in dirty water e.g. cholera
Air-pathogens can be carried in the air and can be breathed in. Some airborne pathogens are carried in the air and droplets produced when you cough or sneeze
Direct contact-some pathogens can be picked up by touching contaminated surfaces, including the skin e.g. athletes foot
What is measles?
How was it caused?
Measles is a viral disease. It is spread by droplets from an infected persons sneeze or cough
People with measles developed a red skin rash and a show signs of fever
Measles can be serious or even fatal if there are complications. E.g. measles can sometimes lead to pneumonia or brain infection cord encephalitis
Most people are vaccinated against measles when they’re young measles is a viral disease. It is spread by droplets from an infected persons sneeze or cough
People with measles developed a red skin rash and of show signs of fever
Measles can be serious or even fatal if there are complications. E.g. measles can sometimes lead to pneumonia or brain infection called encephalitis
Most people are vaccinated against measles when they’re young
What is HIV
How was it caused
HIV is a virus spread by sexual contact or by exchanging bodily fluids such as blood. This can happen when people share needles when taking drugs
HIV initially causes flu like symptoms for a few weeks. Usually, the person doesn’t then experience any symptoms for several years. During this time, HIV can be controlled with Antiretroviral drugs. The stop the virus replicating in your body
The virus attacks the immune cells
If the body is immune system is badly damaged, it can’t cope with other infections or cancers. At this stage the virus is known as late stage HIV infection or AIDS
What is tobacco mosaic virus
What does it calls
Tobacco mosaic virus or TMV is a virus that affects many species of plants e.g. tomatoes
It causes the Mosaic pattern on the leaves of the plant-part of the lease has become discoloured
The discolouration means the plant can’t carry out photosynthesis so the virus affect growth
What is rose blackspot disease
What does it cause
Rose blackspot is a fungus that causes purple or black spots to develop on the leaves of rose plants. The leaves can then turn yellow and drop off
This means that less photosynthesis can occur so the plant does it grow very well
It spreads through the environment in water or by the wind
Gardeners can treat the disease using fungicides and by stripping the plant of its affected leaves. Please leave the need to be destroyed so that the fungus can’t spread to other rose plants
What is malaria
How was it caused
What does it cause
Malaria is caused by a protest
Part of the malarias protests life-cycle takes place inside the mosquitoes. The mosquitoes actors vectors they pick up malarial protest when they feed on an infected animal
Every time a mosquito feed on another animal infected by inserting the protest into the animals blood vessels
Malaria causes repeating episodes of fever. It can be fatal
The spread of malaria can be reduced by stopping the Mosquitoes from breeding
People can be protected from mosquitoes using insecticides and mosquito nets
What is salmonella
How can you get it
What are the symptoms
Salmonella is the type of bacteria that is causes Food poisoning
Infected people can suffer from fever, stomach cramps, vomiting and diarrhoea
This symptoms are caused by the toxins that the bacteria produces
Salmonella is caused by eating food that’s been contaminated with salmonella bacteria e.g. chicken or food that has been contaminated by being prepared in unhygienic conditions
What is gonorrhoea
how was it caused
what does it cause
Gonorrhoea is an STD
STDs are passed on by sexual contact
Gonorrhoea is caused by bacteria
Personal gonorrhoea will get pain when they urinate. Another symptom. Is a thick yellow or green discharge from the vagina or the penis
It was originally treated with an antibiotic called penicillin but this has become trickier now because strains of the bacteria become resistant to it
How can you reduce or prevent the spread of diseases
Being hygienic e.g. washing hands
Destroying Vectras e.g. getting rid of the organisms that spread disease
Isolating infected individuals
Vaccination
What is the bodies defence system
The skin acts as a barrier to the pathogen. It also secretes antimicrobial substances which kill pathogens
Hair and mucus in your nose trap particles that could contain pathogens
The trachea and bronchi I secrete mucus to trap pathogens
The trachea and bronchi I aligned with cilia. These are hairlike structures which waft the mucus up the back of the throat work can be swallowed
The stomach produces hydrochloric acid which kills pathogens that make it that far from the mouth
How does the immune system attack pathogens
White blood cells can engulf foreign cells and digest them . This is called phagocytosis
Every invading pathogens has a unique molecules on its surface called antigens. When some types of white blood cell come across a foreign antigen they will start to produce proteins called antibodies to log on to the invading cells so that they can be found and destroyed by other white blood cells. Antibodies produced on specific to that type of antigen. This means they won’t lock onto any others. Antibodies are then produced rapidly and carried around the body to find all the symbol of bacteria or virus. If the person is infected with the same pathogen again the white blood cells rapidly produce antibodies to kill it. The person is naturally immune to that pathogen and won’t get ill
How does vaccination protect from future infections
Vaccinations involve injecting small amounts of dead or inactive pathogens. These carry antigens which cause your body to produce antibodies to attack them even though the pathogen is harmless. Once pathogen is of the same type appear after that the white blood cells can rapidly must produce antibodies to kill off the pathogen
What are the disadvantages of vaccination
Vaccines don’t always work sometimes they don’t give you immunity
You can sometimes have a bad reaction to a vaccine e.g. swelling or maybe something more serious like a fever or seizures. However this is very rare
What are the advantages of vaccination
Vaccines have helped control lots of communicable diseases that once common in the UK. Smallpox no longer occurs at all and polio infections have fallen by 99%
Big outbreaks of disease called epidemics can be prevented if a large percentage of the population is vaccinated. That way even the people who aren’t vaccinated or on likely to catch disease because there are fewer people able to pass it on
How can bacteria become resistant to antibiotics
Bacteria can mutate. This causes them to be resistant to an antibiotic
If you have an infection some of the bacteria might be resistant to the antibiotics
This means that when you treat the infection only the non-resistant strains of bacteria will be killed
The individual resistant bacteria will survive and reproduce, and the population of the resistant strain will increase
This resistant strain could cause serious infection that can’t be treated by antibiotics
To slow down the rate of development of resistant strains is important for doctors to avoid over prescribing antibiotics so you won’t get them for sore throat only things more serious
It’s also important that you finished the whole force of antibiotics and don’t just stop when you feel better
What are the three main stages of drug testing
Explain what they are
Preclinical testing-
Drugs are tested on human cells and tissues in the lab. However you can’t use human cells and tissues to test drugs that affect hold on multiple body systems e.g. testing a job for blood pressure must be done on an animal because it it has an intact circulatory system
Live animals-
the Next step in preclinical testing is to test the job on live animals. This is the test efficiency, to find out about is toxicity And how often should be given.
Some people think it’s called a test on animals but others believe is the safest way to make sure drivers and dangerous before giving it to humans
Clinical trials-
First the drug is tested on healthy volunteers. This is to make sure that it doesn’t have any harmful side-effects when the body is working normally. At the start of the trial a very low dose of the drug is given and this is gradually increased
If the results of the test on the healthy volunteers are good the drugs can be tested on people suffering from illness.
To test how well the drug works, patients are randomly put into two groups. One is given the new drug and the other is given a placebo. This is so the doctor can see the actual difference the drug makes. It allows for the placebo effect
Clinical trials are blind-the patient in the study doesn’t know whether they are getting the Jerge all the placebo. Double-blind trials is when neither the patient know the doctor knows until the results have been gathered. This is so the doctor is monitoring the patient and analysing the results on subconsciously influenced by their knowledge.
The results of drug testing and drug trials aren’t published until they’ve been through peer review to prevent falls claims
