communicable diseases Flashcards
(27 cards)
Explain how diseases caused by viruses, bacteria, protists and fungi are spread in animals and plants.
Microbes can be spread in a manner of ways, including being digested, coming into contact with skin, being inhaled, being absorbed into the blood through the eyes, through sexual contact.
They are communiable diseases and transmitted by people, insects, plants, animals and contact of the microbe.
Define the term pathogen
a disease-causing micro organism
Explain how bacteria and viruses may reproduce in the body and why they make you fell ill
They cause illness by releasing toxins into the bloodstream, which cause harm. Viruses attack cells and rapidly reproduce inside of them. Bacteria reproduce via binary fission since they are prokaryotes. By reproducing they can rapidly expand their population and ability to cause harm.
Give examples of how the spread of diseases can be reduced
By taking steps to be hygienic, such as washing hands and avoiding contact with a sick person. Diseases are spread when pathogens enter a person, so by cleaning surfaces with disinfectants, and washing yourself with antiseptics, you can avoid pathogens entering you. Also, using contraception during sexual intercourse can prevent the spread of STDs
Know that Measles is a viral disease and describe the symptoms
Measles is a virus that causes painful rashes in the host. It is highly infectious and often caught by children. There is vaccine available which is used in developed countries, but not always in lesser developed nations. When caught as an adult but not a child, it can be much more serious and cause infertility in women
Explain the effects of HIV and how it is transmitted
HIV is an STD/STI and a virus that is very serious and can lead to AIDS. It stands for Human Immunodeficiency Virus and is spread via sexual contact, through blood contact, and through the contact of bodily fluids, such as semen. It can be prevented through the use of contraception, such as male and female condoms. WHen left untreated, symptoms can tend to develop that are groupas as AIDS - Aquired Immunodeficiency Syndrome, where the human immune system becomes too weak to fight off any infections, including basic ones such as a cold
Describe tobacco mosaic virus (TMV)
Affects plants of tobacco species and similar varieties, such as pepper and tomatoes. Infects the chloroplasts in plants leaves, which affects the plants ability to photosynthesize, until eventually, where if the virus becomes to strong, the plant is killed. The symptoms are stunted growth and blotchy blotches on the leaves.
Know that Salmonella food poisoning is spread by bacteria ingested in food, or on food prepared in unhygienic conditions.
A bacteria pathogen that causes food poisoning. Can be spread by uncooked or poorly reheated poultry, meat and eggs. Also, from unhygienic kitchens and it being spread from person to person. As a result, all animals in the UK are given a salmonella vaccine to prevent infection.
Describe the symptoms of salmonella food poisoning
Abdominal pains, stomach cramps, vomiting, and diarrhoea
Know how Gonorrhoea is a transmitted and how its spread can be reduced.
Is a STI bacteria that is transmitted during sexual intercourse, Can be prevented from abstaining from intercourse or using contraception, like condoms
State the cause of Gonorrhoea and describe the symptoms and how it is treated
Pain experienced whilst urinating, yellow discharge from genitals, infertility problems. Can be treated with courses of antibiotics but scientists fear that they may one day stop working, as the bacteria develops resistance.
Describe rose black spot and state its cause
A fungus that affects roses. Causes black blotches on the leaves, an the rest of the leaf turns yellow. The leaves may consequently fall of the plant, and therefore the rose’s ability to photosynthesize is reduced.
Know how rose black spot is spread in the environment and how it can be treated
It can be transmitted through the air or through water, as well as from dead leaves. Can also be spread by humans using contaminated equipment. Can be treated with fungicides.
Describe malaria and state its cause
Malaria is a protist, which is a type of pathogen. It is spread by mosquitoes, which suck infected peoples blood, and then transmit the disease when they suck someone else’s blood. The symptoms are severe, including fever, sweating, vomit, diarrhoea and headaches. Half the 200 million that are infected each year, half die from the infection.
Know how malaria is spread and how to reduce the spread of the disease
It is spread by mosquitoes, who transmit the disease in blood. The spread of the infection can be prevented by preventing mosquito bites: through mosquito nets, anti-mosquito creams and repellents. The disease is prevalent in hot places such as in Africa, South America and Asia. Also, antimalarial drugs can be taken to treat the symptoms and prevent infection in the first place.
Define some of body’s natural defences to infection
- Skin
- Mucus in the throat
- Nose hairs
- Eyelashes
- The immune system
- Ciliated epithelial cells in the throat
- Ear hairs
- Ear wax
- Immune system
Explain to role of white blood cells
There are several types:
- Lymphocytes - Recognise and identify the specific antigens of a microbe in the bloodstream. Produces antigen-specific antibodies to attach to the pathogen and neutralise it. Also produces antitoxins to neutralise the toxins released by the pathogen. Also remembers the immune response to previously encountered microbes, so offers immunity.
- Phagocytes - Engulf and ingest pathogens, to essentially kill them in the process of phagocytosis
Explain how growing bacteria on agar can be used to determine the effectiveness of disinfectants or antibiotics
Using agar plates and bacteria colonies you can safely determine the effectiveness of treatments, in a controlled experiment. It is easy to set up, cheap, quick, safe and offers easy comparability between different treatments. By measuring the area of inhibition after an experiment, you can judge the effectiveness of a treatment against a bacteria
Describe the process of vaccination
During vaccination, a dead, weakened, inactive or similar form of the desired pathogen is released into the bloodstream. It stimulates an immune response, and the lymphocytes begin to develop antibodies to attach to the pathogen’s specific antigens. However, since the vaccine contains only non-harmful weak versions of the microbe, no harm is posed. The lymphocytes neutralise the pathogen, but the memory cells remember the specific antibodies created, so next time the microbe was encountered, production of the antibodies could begin right away. Immunity is achieved to that specific pathogen.
Explain “herd immunity”
Herd immunity is where there are enough vaccinated people within a population or group of people that pathogens are essentially wiped out, as they don’t have enough hosts to infect so that they can multiply.
State what antibiotics can treat and explain the development of antibiotic resistance bacteria
Antibiotics are treatments that can be used to treat bacterial infections only. They are drugs that can treat or prevent bacterial infections, by killing the bacteria or preventing them from spreading and reproducing. However, when used to kill bacteria but not used enough to kill all bacteria, the pathogen develops resistance against the antibiotics, so the antibiotic could no longer be used effectively against that particular strain of the pathogen.
Define painkillers
Painkillers are drugs that suppress the pain and relieve symptoms but do not actually treat the infection. They merely prevent the person from feeling the pain of the infection
Explain why it is difficult to develop drugs that kill viruses
Because viruses are completely different to bacteria, as they inhabit and reproduce inside of a human cell. The virus outer layer, the viral envelope, is very similar to human cell membranes, so its difficult to produce a drug that targets just the virus.
A virus is a type of very small pathogen that cannot reproduce on its own. Once it enters a living cell, it begins to reproduce and multiply. From there, it infects more cells and causes harm in the body.
Know that traditionally drugs were extracted from plants and microorganisms and give some common examples including who discovered Penicillin and from what
Drugs were first natural remedies produced from plants and herbs. Common examples are:
-Ibuprofen
-Paracetamol
-Aspirin
-Penicillin.
Penicillins were first created by Alexander Fleming and are antibiotics that have saved many lives throughout their existence. It was first discovered from a mould that prevented a bacterial infection to grow
