Topic 5 Flashcards
What is the World Health Organisation’s (WHO) definition for health?
“A state of complete physical, mental and social well being and not merely the absence of infirmity or disease”
What is infirmity?
Weakness or frailness, commonly due to old age
What is disease?
Disease is a condition in which part of an organism does not function properly
What are two types of disease?
Communicable and noncommunicable disease
What are communicable diseases?
Communicable diseases are diseases that can be spread between individuals
What are non- communicable diseases?
Non-communicable diseases are diseases that cannot be transmitted between individuals
If you are affected by one disease, what may happen?
If you are affected by one disease it can make you more susceptible to other diseases - your immune system may become weakened by the disease, so it is less able to fight off other diseases
What are pathogens?
Pathogens are organisms such a viruses, bacteria, fungi and protists that cause communicable diseases
What are the communicable diseases you need to know?
Cholera Tuberculosis Stomach Ulcers Chlamydia HIV Ebola Malaria Chalara Ash Dieback
What pathogen causes Cholera?
A bacterium called Vibrio cholerae.
What pathogen causes Tuberculosis?
A bacterium called Mycobacterium tuberculosis.
What pathogen causes Stomach ulcers?
A bacterium called Helicobacter pylori.
What pathogen causes Chlamydia?
A bacterium called Chlamydia trachomatis
What pathogen causes HIV?
A virus.
What pathogen causes Ebola?
The Ebola virus
What pathogen causes Malaria?
A protist
What pathogen causes Chalara ash dieback?
A fungus
What are the symptoms of Cholera?
Diarrhoea.
What are the symptoms of Tuberculosis?
Coughing and lung damage.
What are the symptoms of Malaria?
Damage to red blood cells and, in severe cases, to the liver.
What are the symptoms of Stomach ulcers?
Stomach pain, nausea and vomiting.
What are the symptoms of Ebola?
Haemorrhagic fever (a fever with bleeding).
What are the symptoms of Chalara ash dieback?
Leaf loss and bark lesions (wounds).
What are the symptoms of Chlamydia?
Although it doesn’t always cause symptoms, it can result in infertility in men and women.
How is Cholera spread?
Via contaminated water sources
How is Tuberculosis spread?
Through the air when infected individuals cough
How is malaria spread?
Mosquitoes act as animal vectors (carriers) - they pass on the protist to humans but don’t get the disease themselves.
How are Stomach ulcers spread?
By oral transmission, e.g. By swallowing contaminated water or food
How is Ebola spread?
Via bodily fluids
How is Chalara ash dieback spread?
It is carried through the air by the wind. It also spreads when diseased ash trees are moved between areas.
How can Cholera be reduced?
By making sure that people have access to clean water supplies.
How can Tuberculosis be reduced?
Infected people should avoid crowded public spaces, practise good hygiene and sleep alone. Their homes should also be well-ventilated.
How can malaria be reduced?
By the use of mosquito nets and insect repellent to prevent mosquitoes carrying the pathogen from biting people.
How can stomach ulcers be reduced?
By having clean water supplies and hygienic living conditions
How can ebola be reduced?
By isolating infected individuals and sterilising any areas where the virus may be present
How can Chalara ash dieback be reduced?
Removing young, infected ash trees and replanting with different species. Restricting the import or movement of ash trees
What does being susceptible to a disease mean?
You are more likely to get the disease
What are viruses?
Usually no more than a protein coat around a strand of genetic material
How do viruses reproduce by the lytic pathway/cycle?
1) the virus attaches itself to a specific host cell and injects its genetic material into the cell
2) the virus uses proteins and enzymes in the host cell to replicate its genetic material and produce the components of the new viruses
3) the viral components assemble
4) the host cell splits open, releasing the new viruses which infect more cells
How do viruses reproduce?
By infecting living cells (host cells), specific types of viruses will only infect specific cells
What does it mean if a virus is dormant?
It is inactive
How do viruses reproduce in the lysogenic pathway/cycle?
- GM is incorporated into genome of host cell
- Viral GM and host DNA replicate when host cell divides but virus remains inactive. (no new viruses being made)
- Trigger (chemical) causes GM to leave genome and enter the lytic pathway
What are the two STIs you need to know about?
HIV and Chlamydia
Some STIs are not only spread by sexual intercourse but what else? Give an example of an STIs which is spread in this way.
Chlamydia, genital contact
What are the lytic and lysogenic pathways /cycles?
Parts of the life cycle of a virus
What is HIV?
- the Human Immunodeficiency Virus
- A virus which kills white blood cells (these are needed to trigger an immune response, so it can make a person very vulnerable to infections by other pathogens)
How is HIV spread?
Through bodily fluids
How can the spread of HIV be prevented?
Use a condom during sex. Drug users should avoid sharing needles, an infected person should be screened so they have receive proper treatment and medication.
What are some examples of bodily fluids which could be infected by HIV and therefore could spread HIV?
Blood, semen, vaginal fluids
What does HIV lead to?
AIDS