B5: Health & Disease Flashcards
Give 3 examples of viruses
Measles
HIV
TMV (Tobacco Mosaic Virus)
Give two examples of Bacteria
Salmonella
Gonorrhoea
Give 2 examples of Fungal and Protist Diseases
Rose Black Soot (fungal)
Malaria (protist)
What are viruses?
- They are very microscopic germs that infect hosts to reproduce
- They invade cells and then reproduce inside those cells using a host. As they do this, they cause damage to the cells
- As the cells are damaged, this leads to symptoms of the disease
What are the main symptoms of measles?
- Feaver
- Red skin rash
- May cause blindness and brain damage
How is measles spread?
Inhilation of droplets form coughs and sneezes and is very infectious
How is measles treated?
There is no treatement for measles so if someone becomes infected they must isolate
Why is measles in the UK now rare?
As a result of improved living conditions and a vaccination programme for young children
What are the symptoms of HIV to begin with?
Mild, flue-like illness
How does HIV cause damage? How does it lead to AIDS?
HIV aftacks the immhne cells and after rhe initial mild illness remains hidden indside the immune system until the immune system can no longer deal with any infections. At this point, the patient develops AIDS
How is HIV spread?
Sexual contact and the exchnge of bodily fluids such as blood when drug users share needles pr when unscreened blood is used for transfusions. Can be passed on to a child through the mother’s breast milk.
How is HIV treated?
There is no treatement for HIV however it can be prevented by not sharing needles, using condoms, screening blood for transfusions and bottle feeding children. Furthermore, the regular use ofantiretroviral drugs can prevent the development of AIDS for many years,
Which plants are effected by the Tobacco Mosaic Virus?
Affects over 150 species of plants including tomatoes and tobacco plants
Why is it called a ‘mosaic’ virus?
Causes a distinctive mosaic pattern of discoloration on the leaves as teh virus destroys the cells.
How is TMV spread?
Spread by contact between diseased plant material and healthy plants and insects can act as vectors
How is TMV treated?
There is no treagment and farmers now grow TMV-resistant strains of many crop plants. Good field hygeine and pest control can prevent the spread of TMV
What are bacteria?
Bacteria are small, single-celled, prokaryotic organisms that are very different to plant and animal cells
What are salmonella and where are they found?
Salmonella are bacteria that live in the guts of many different animals. They can be found in raw meat, poultry eggs amd egg products.
What are the symptoms of salmonella infection!
Fever, abdominal cramps, vomiting, and darrnoea
How can salmonella infection be prevented?
In the Uk, poultry are vaccinated against salmonella to control the spread. Keep raw chicken away from food that is eaten uncooked, avoid washing raw chicken, wash ahdns and surfaces well after handling raw chicken, cook chicken thouroughly
What is Gonorrhoea?
A Sexually Transmitted Disease
How is Gonorrhoea spread?
Soread by unprotected sexual contact with an infected person
What are the long and short term symptoms of gonorrhoea?
Early symptoms:
Thick yellow or geen discharge from the vagina or penis, pain on urination
Long term:
Untreated gonorrhoea can cause long term pelvic pain, infertility and ectopic pregnancies, babies born witn severe eye infection and even become blind
How is Gonorrhoea treated?
Csn be treated with antibiotics. Originally easily cured usinf penicillin bur now many antibiotic-resistant strains of gonorrhoea have evolved: more difficult to treat. Spread can be prevented by using a barrier method of contraception.
What are Fungal cells?
Fungal cells are much more similar to plant and animal cells than bacteria
What are protists?
A Protist is a unicellular, eukaryotic organism that are relatively rare pathogens. A significant number of protists are pathogenic parasites that must infect other organisms to survive and propagate.
What are the symptoms of rose black spot infection?
Causes purple or black spors to develop on the leaves. Leaves often turn yellow and drop early.
How is Rose Black Spot spread?
Spores of the fungus are spread in the environment, carried by the wind. They are then spread over the plant after it rains in drops of water, then splash from one leaf or plant to another.
How can the spread of Rose Black Spot be treated?
Removing and burning affected leaves and stems. Chemical fungicides can also help to treat the disease and prevent it from spreading. Horticulturists have bread types of roses that are relatively resistant.
The protist that causes malaria is referred to as a ‘parasite’- what does this mean?
They live and feed on other living organisms
How are mosquitos involved in the spread of the malarial protist parasite?
The protist reproduce sexually in the mosquito. The mosquitoes then act as vectors of the disease. The female mosquito needs two meals of hi,an bood before laying her eggs. This is when the protist is passed into the human blood stream. The protists travel through the circulatory system and affect the liver and damage red blood cells
What are the symptoms of malaria?
Recurrent episodes of fever and shaking when the protists burst out of the blood cells and it can be fatal. Affects the liver and damage red blood cells.
Give four ways the spread of malaria can be controlled?
- Using insecticide- impregnate insect nets to prevent mosquitos biting humans
- Using insecticides to kill mosquitos
- Preventing the vectors from breeding by removing standing water and spraying water with insecticides, to kill the larvae
- Travellers can tale antimalarial drugs, killing the parasites in the blood if bitten by an infected mosquito
What is health?
A state of physical or mental wellbeing
What is disease?
Illness caused by infection or a faliure of health other than by accident
What are infectious diseases called?
Transmissable/ communicable
What are communicable diseases caused by?
Pathogens (microorganisms that can cause disease) such as bacteria, fungi and protists
What are three examples of factors that can affect health?
Diet- If you do not eat enough or the right nutrients, you may suffer from disease (malnutrition, starvation, aneamia, deficiency). The same may be caused if you eat too much food or the wrong types (coronary heart disease, type 2 diabetes, obesity)
Stress- Stress may be linked to an increased risk of developing a wide rabge of health problems.
Life situations- Where you love, financial status, ethnic group, levels of free health care provided etc..
Give one way a poor diet can effect your immune system?
Poor diets can affect your immune sustem which increases the risk of communicable disease as deficiency in vitamins or minerals can lead to a compromised immune system
What is a long term disease called?
Chronic
What is a short term disease called?
Acute disease
Why may severe physical ill-health lead to poor mental health?
Sever physcial ill-health can lead to poor mental health as it can limit exercise and movement, often resulting in poor mental health or alternat ediseases. It may also result in depression and stress, potentially cannot work or be active whatsoever. Lack of social interaction. Long-term pain management. Medical drugs/ treatment may impact mental health.
What are three ways pathogens can be spread!
By air
By physical contact
By water
How can pathogens be spread by air?
When you are ill, you expel droplets full of pathogens when you sneeze, cough or talk. Other people then breathe these droplets in.
How can pathogens be spread by direct contact?
Common in plant disease where ating piece of an infected plant material left in a field can infect an entire new crop. In people, diseases such as STIs are spread by direct contact of the skin. Animals may act as vectors of both plant and animal diseases by carrying a pathogen.
How can pathogens be spread by water?
Fungal spores carried in splashes of water often spread plant diseases. For humans, eating raw, undercooked or contaminated foor or wate can spread diseases. The pathogen enters your body through your digestive system.
What are vectors?
Organisms that transmit disease
How do bacteria cause disease?
Bacteria can divide rapidly by splitting in two through binary fission. They may produce toxins that can affect your body and at times directly damage your cells.
How do viruses cause disease?
Viruses take over your body. They live and reproduce inside the cells, damaging and destroying them as they replicate and burst the cell.
What are 4 ways to prevent the transmission of disease?
Hygiene
Isolating infected individuals
Destroying/ controlling vectors
Vaccination
How may hygiene prevent the transmission of disease?
• Handwashing
• Using disinfectants on surfaces
• Keeping raw meat away from uncooked meat
• Coughing/sneezing into a tissue
• Cleaning farming equipment
How may isolating infected individuals prevent the transmission of disease?
If someone has an infectious disease they must be kept in isolation. The fewer healthy people who come into contact with the infected, the less likwly it will be that pathogens will be passed on. Plants infected with disease may also be moved or destroyed
How may destroying/ controlling vectors prevent the transmission of disease?
Some communicable diseases are passed on by vectors. Houseflies can carrry over 100 human diseases, while rats also act as vectors of disease. If the vectors are destroyed, the spread of the disease can be prevented.
How may vaccination be used to prevent the transmission of disease?
- Doctors introduce a small amount of a harmless form of a specific pathogen into ypur body.
- As a result, if you come into contct with the live pathogen, you will not become ill as your immune system will be prepared
- Very successful way of protecting large numbers of humans and animals
What was Ignaz Semmelweis contribution to disease transmission?
- In the mid 19th century he was a doctor in Vienna, frustrated by the situation where healthy women would often die during childbirth due to ‘childbirth fever’- one in five women
- Discovered that doctors would preform autopsies in one part of the hospital and then immediately deliver babies without washing hands
- Once he asked doctors and medical student to practice hand hygeine, the death rate dropped from 18% to 1%
- Much of the medical community in other areas of the world refused his ideas until after his death
What was Louis Pasteur’s contribution to disease transmission?
- Pasteur was the first to challenge beliefs of miasma and spontaneous generation, hypothesising that germs caused disease, not disease causing germs
- Proved milk ‘off’ due to bacteria in the air and argued that this same bacteria could cause disease, known as ‘germ theory’
- Studied cholera in chickens- when injecting an old culture of cholera into birds, they fell ill but didn’t die as expected. From that point on, they were resistant to cholera
- First person to ever create vaccines in a lab
What is miasma?
The miasma theory suggested that diseases are produced due to unhealthy or polluted vapors rising from the ground, or from decomposed material.
What was Joseph Lister’s contribution to disease transmission?
- In 1856, he was a surgeon in Edinburgh Royal infirmary
- Surgery was risky at the time; most patients developed diseases or infections and often died
- Doctors wrongly believed that bad air seeping out of wounds caused infection- ‘ward fever’/ ‘miasma’, often didn’t wash the hospital materials, hands or surgical tools
- Based his beliefs off of Louis Pasteur, goving him the idea that germs could be causing infections and that sterilisation would prevent infections and disease
- Used carbonic acid to clean surgical tools, washed hands and cleaned hands
What was Edward Jenner’s contribution to disease transmission?
- At the time smallpox was a major global epidemic disease, killing over 400,00 per year in Europe
- Milkmaids and shepherds were immune to smallpox- Small blisters formed on their hands from a mild disease, cowpox.
- Hypothesised that a mild disease would protect from serious diseases such as smallpox
- Repeated his experiment of testing patients with smallpox and then cowpox, concluding they would become immune
What are two ways your respiratory system protects you against infection?
- The nose is full of hairs and produces a sticky liquid call mucus. The hairs and mucus trap particles in the air that may contain pathogens
- The trachea and bronchi also secrete mucus that traps pathogens from the air. The lining of the tubes is covered in ciliated epithelial cells, which waft the mucus up to the back of the throat where is is swallowed
What are three ways the skim protects against infection?
- Produces antimicrobial secretions to destroy pathogenic bacteria
- Healthy skin is covered with microorganisms that help keep you health and act as an extra barrier to the entry of pathogens
- Skin covers the body and acts as a barrier, preventing bacteria and viruses reaching the tissues beneath. If you cut or damage your skin, the barrier is broken but is restored by the body as the blood clots.
What is one way the digestive system protects against infection?
Stomach produces acids destroying the microorganisms in the mucus you swallow, as well as the majority of pathogens you take in through your mouth in food and drinks.
What are symptoms of magnesium deficiency (cholorisis)?
Leaves become yellow, rate of growth reduces
What is a symptom of nitrate deficiency?
Stunted growth
How can plant disease be treated?
- Aphids can be destroyed using chemical pesticides or biological pest control in enclosed spaces
- Releasing aphid-eating insects can control the pathogen population
- Mineral deficiencies cam be treated through the use of fertilisers
How can plant disease be detected?
- Comparing the symptoms in the living plant with disease descriptions
- Checking for other plant pests including nematode worms and many insect larvae, living in soil, damaging plants as they feed on the,
- Taking samples of diseased material to identify the pathogen using DNA analysis
What role do aphids play in the spread of plant disease?
- Aphids have sharp mouthparts that penetrate into the phloem vessels of the plant so they can feed on the sugar-rich phloem sap.
- Aphids also attack in huge numbers, further depriving the plant cells of the products of photosynthesis, weakening and damaging the plant, thus making them more vulnerable to plant disease.
- Aphids can also act as vectors, transferring olant diseases into the healthy tissues of plants on their mouthparts
How do plants defend against disease using physical defences/ barriers?
- The cellulose cell walls that strengthen plant cells also help to resist invasion by microorganisms. If the barrier is breached, it gives pathogens a way into the cells
- Bark on trees, a layer of dead cells on the outside of stems, form a protective layer that is hard for pathogens to penetrate. When these cells are shed, the pathogens fall off with them.
- Leaf fall- deciduous trees lose their leaves in autumn. Any pathogens that infect the leaves fall off the tree when leaves are lost
- The tough waxy cuticle on the surface of leaves acts as a barrier to the entry of pathogens
What are plant defences against herbivores?
- Thorns to make it unpleasant or painful for large herbivores to eat them; unlikely to deter insects
- Hair on stems or leaves deter insects and larger animals from feeding on them or laying eggs on the stems or leaves
- Dropping or curling when touches, dislodging insects and frightening larger animals
- Mimicry- some plants droop to mimic unhealthy plants and tricks animals into not eating them
What are chemical defences plants use to defend against disease?
- Compounds from plants including pines, cypress, and euphorbias also have promising antibiotic properties
- Many plants produce antibacterial chemicals that protect them against invading pathogens, these are very effective at preventing bacterial diseases in many plants
What do white blood cells produce to defend against pathogens?
Antitoxins/ Antibodies
What is a lymphocyte?
Lymphocytes are a type of white blood cell. They help your body’s immune system fight cancer and foreign viruses and bacteria.
What part pf the human body does malaria affect?
Red blood cells and the liver
How do fungi cause disease?
Many multicellular fungi grow hyphae through soil and potentially penetrating human skin, spreading disease. They also release spores of the disease.
