(Module 5) Communicable Diseases Flashcards
Differences between the two types of diseases
Communicable diseases: these can be spread e.g the flu and a cold
Non communicable: these cannot be spread e.g heart disease
Can be got by a deficiency, a body disorder or a genetic inheritance
Other factors which can affect health
Diet Stress Life situations e.g: Where you live Your gender How many kids you have How far your local dump is Access to health care
What are microorganisms which cause disease called
Pathogens
What types can pathogens be
Bacteria
Fungi
Protist
Viruses
What are the most common pathogens in plants vs animals
Animal: bacteria and viruses
Plants: viruses and fungi
What are the differences between bacteria and viruses
Basically, bacteria are cells of their own, but single celled, whilst viruses take control of your cells
Bacteria are prokaryotic
They are single celled organisms that are smaller than plant and animal cells
Bacteria can be good, we have 1/2 kg of bacteria
More good bacteria than bad
Viruses are even smaller, and cause diseases in all types of living organism
Have regular shapes
How pathogens cause disease
Bacteria divide rapidly by splitting into 2
They may produce toxins (poisons) which make you feel ill
They can directly damage the cell
Viruses take over the cells of the body
They live and reproduce in the cells, damaging and destroying them
Common symptoms of diseases
High temperature
Headaches
Rashes
They are caused by the ways the body responds to the cell damage and toxins produced by the pathogens
How are pathogens spread for humans
A: by air
In humans, droplets of the pathogens from the breathing system are spread by sneezing, coughing or talking, and are breathed in by another
B: direct contact
Diseases can be spread by sexual relations, cuts, scratches and needle punctures
C: by food/water
Diseases can be spread by eating raw, undercooked or contaminated food. As well, drinking water containing sewage
Pathogens enter the body through the digestive system
How are pathogens spread for plants
A: by air
For plants, virus, bacteria and fungal spores are spread in the air from one plant to another
B: direct contact
If part of an infected plant is left in a field, it can infect a completely new plant. Animals can also carry plant diseases
C: water
Fungal spores in water can spread diseases
What did Igual Semmelweis do
He noticed some medical students deliver a baby after dissecting a body without washing their hands. More mums died in pregnancy through medical students than mid wives
He also saw a doctor die with symptoms identical to childbed after cutting himself while dissecting a body
He asked medical students to wash their hands before delivering babies
Doctors were against this at the start
Other preventing diseases discoveries
Louis Pasteur discovered microorganisms caused diseases. He also created vaccines
Joseph Lister started using antiseptic chemicals to destroy pathogens before they caused infection in operating theatre
As microscopes improved, people could see pathogens
How to prevent the spreading of communicable diseases
Hygiene:
Washing hands, cleaning kitchen surfaces, maintaining agricultural machinery
Isolating infected individuals:
The less healthy people who visit someone ill (especially one with a very serious disease) the better
Destroying or controlling vectors:
Vectors are things like mosquitos, house flies or rats (and aphids for plants, and beetles). If those vectors are destroyed, than less diseases are carried
Vaccines
How do vaccines work
A dead or harmless form of a pathogen is injected, so the body recognises the antigen of the pathogen, so if a real, dangerous version of pathogen enters the body the body will recognise it and act quickly.
Examples of viral diseases and facts
Measles:
Main symptoms are a fever and red skin rashes
Can cause blindness, brain damage or even be fatal
No cure, but vaccines are now common and conditions have improved enough in the UK
HIV into aids:
1.5 million infected worldwide
Spread by sexual contact and the exchange of bodily fluids
First symptoms are just a mild flu, so most don’t recognise it
It attacks the immune system, remains hidden, up until the immune system is too weak to fight back. From there, it becomes aids
No cure or vaccine, but can be stopped spreading by condoms or not sharing needles
Use of antiretroviral drugs stops the development of aids, making them live normal. But uncommon in South Africa.
Tobacco mosaic virus:
Attacks plants.
Destroys cells in leaves, which stops plant growth as those cells don’t photosynthesise
Cannot be treated or cured, but farmers grow TMC immune plants
Example of bacterial diseases and facts
Salmonella food poisoning:
Is a bacteria which lives in many animal type guts
Caught through undercooked food, or food prepared in unhygienic conditions
Causes fever, cramps, vomiting and diarrhoea
Gonorrhoea:
Sexual transmitted disease
At first, a thick yellow or green discharge is releases from the sexual organ and pain urinating. Then, the disease becomes symptomless for 10% of men and 50% of women
Could be treated with penicillin, but then it developed and the antibiotics stopped working effectively. Antibiotics are used to treat it
Can lead to pelvic pains and infertility
Some babies born by infected mothers can have eye problems, and can become blind
Can be stopped by condoms or less sex with less people
Mot many bacteria diseases for plants
Agrobacterium tumefacciones:
A mass of unspecialised cells grow at the roots and the shoots of the infected plant
Infects many plants such fruit plants, vegetables and garden flowering plants
Diseases caused by fungal diseases
For humans:
Athlete foot is a common foot fungal disease - anti fungal drugs can be used
Broken heart valves can develop fungal diseases
For plants:
Rose black spot:
Causes black or purple spots to appear on rose leafs. They turn yellow and fall early, which hurts the plants as less leaves photosynthesis
Spread by spores in water droplets
Farmers stop the disease by burning infected leaves and stems
Chemical fungicides also stop the disease
Diseases caused by Protists
*Require a vector
Malaria:
The protist is carried around in mosquitos and transferred when the female mosquito feeds off human blood. It travels around the circulatory system. It affects the liver and red blood cells
It causes shakes and shivers as the protists blow up the red blood cells
It affects the infected person, making them weak, even if they do not die
Can be treated with a combination of drugs, which are not generally accessible for all
Can be stopped by
Mosquito nets
Killing mosquitos with insecticides
Preventing the vectors from mating in stranding water fields, and spraying water with insecticides to kill the parasites
Antimalarial drugs can kill the parasites
How the skin is part of the bodies defence system
It act as a barrier
Prevents viruses and bacteria from entering
If there is a cut, platelets block it up
The skin has antimicrobial secretions that destroy pathogens
Healthy skin has microorganisms that are an extra border
Defences of the respiratory system and the digestive system
The nose is full of airs and produces a liquid called mucus
Both collect pathogens which could irritate the lungs
The trachea and bronchi also release mucus to catch pathogens in the air
The lining of the tubes have tiny hairs called cilia which beats to pump mucus into the throat were it is swallowed
The stomach acid destroys microorganisms in the mucus you swallow, and most pathogens in foods and drinks
How white blood cells work
A: Ingesting organisms
Some white blood cells ingest pathogens, digesting and destroying them so they don’t make you ill (phagocytes)
B: producing antibodies
Antibodies target particular bacterias or viruses and destroy them
Antibodies latch on to antigens. Each pathogen has a unique antigen, and once antibodies latch on to one pathogen, they will always recognise it
C: Antitoxins
Some white blood cells antitoxins which counteract toxins released from a pathogen
