Flashcards in SB5: Health, Disease And The Development Of Medicines Deck (157)
Health is the state of complete physical, mental and social well-being and not merely the absence of disease or infirmity
What is a disease?
A condition where part of an organism doesn’t work properly
What are communicable diseases usually caused by?
Bacteria, viruses, fungi and parasites
What are two types of causes of non-communicable diseases?
Genetics and lifestyle factors
If a person has AIDS, why do they have an increased chance of suffering from diseases like flu?
A person with AIDS is less able to fight off the pathogen that causes flu because their immune system is weakened by the HIV virus
Explain why bacteria such as Salmonella make you feel ill
They produce toxins (poisons) inside the body that damage cells and tissues
What communicable disease is caused by Helicobacter pylori bacteria?
How do viruses replicate?
They live inside body cells and replicate using the cell’s machinery to produce many copies of themselves
How do viruses spread within the body?
Infected cells eventually burst and release the new viruses into the tissue and/or blood
What makes you feel ill when you have a viral infection?
The cell damage caused by infected cells bursting
What are protists?
Eukaryotic organisms that are usually unicellular
What are parasites?
Organisms that live on or inside other organisms and can cause them damage
How do fungi, made up of hyphae (thread-like structures), cause disease in animals and plants?
The hyphae grow and penetrate the skin or surface of plants causing disease. The hyphae can produce spores which can be transferred to other plants and animals
Give an example of a plant disease caused by fungi
Chalara Ash die-back disease
Give examples of human diseases caused by fungi
- Athlete’s foot
State five methods that pathogens are spread
1. Drinking or bathing in dirty water
2. Airborne (carried in air)
3. Swallowing contaminated water or food
4. Bodily fluids e.g blood, vomit, saliva
5. Animal vectors transmit pathogens
What could infected individuals do to reduce the spread of a pathogenic bacteria?
1. Isolate themselves
2. Avoid crowded public spaces
3. Sleep alone
4. Practise good hygiene - cover mouth and nose with tissue when coughing and sneezing, disposing of tissues in a bin
5. Good ventilation can reduce likelihood of transmission
What are the main symptoms of an infection caused by Vibrio cholerae?
Diarrhoea that lasts for a few days leading to severe dehydration and ultimately, if untreated, death
How is the pathogen Vibrio cholerae spread?
Through contaminated water sources
Explain why most cases of cholera occur in developing countries
Clean water is not widely available
How can the spread of cholera be reduced?
By making sure that everyone has access to clean water supplies
How does the Heliobacter pylori bacteria cause stomach ulcers?
It inflames the stomach lining which can lead to the lining becoming damaged. The damage allows stomach acid to penetrate the stomach lining, creating a hole (the ulcer) that exposes the tissue underneath
What are the symptoms of stomach ulcers?
Stomach pains, nausea and vomiting
How can the transmission of Helicobacter pylori be reduced?
- clean water supplies
- hygienic living conditions: disinfecting food preparation areas, washing hands before eating or handling food, keep toothbrushes separately
- infected people should not prepare or serve food
- thorough cleaning of utensils
What is Ebola and what does it cause?
A virus that causes haemorrhagic fever
Describe the symptoms caused by Ebola
Fever that causes internal bleeding and bleeding from eyes, nose or mouth, often leading to death
How is Ebola spread?
Through contact with bodily fluids of an infected individual
How was the spread of West African Ebola reduced during the 2013-2016 epidemic? (6 marks)
- infected individuals were isolated from others
- bodies were left untouched until they could be collected by officials wearing protective clothing covering the whole body
- medical staff wore protective clothing coving the whole body
- sterilising areas where the virus may be present
- treatment centres were set up where infected individuals were isolated
- bodies buried in mass graves by people wearing full body protective clothing
- community awareness campaigns about the protective factors individuals could take, eg avoiding contact with infected people and hand washing using soap and water
Describe the symptoms of Chalara ash dieback
Loss of leaves and bark lesions (wounds) leading ultimately to death of tree - directly or because the tree is weakened so much that it cannot defend itself from other pathogens