Topic 5 - Health And Disease Flashcards
What is health ?
Health is a state of physical and mental well-being
What are major contributors to ill health ?
Disease
Stress
Diet
Life situation
What are the two categories of disease ?
Communicable diseases
Non-communicable diseases
What are Communicable diseases?
diseases which can be spread between organisms
What are non-communicable diseases ?
diseases which cannot be spread between organisms.
How can Physical problems impact an individuals mental health ?
Physical problems can negatively impact upon an individual’s mental health.
How are allergies triggered ?
Allergies (e.g. asthma and skin rashes) can be triggered by an immune reaction to a pathogen (a microorganism that can cause disease)
Viruses occupying cells can stimulate what ?
Viruses occupying cells can stimulate (bring about) cancers, for example, the HPV virus can lead to cervical cancer.
A disease that suppresses the immune system (e.g. HIV) makes individuals more susceptible (likely) to what ?
catching other infectious diseases, such as tuberculosis.
Why is HIV dangerous?
It can suppress the immune system and makes people more susceptible to catching other infectious diseases.
How are infections caused ?
Infections are caused whenever a foreign pathogen invades an organism (animal or plant)
What are the four main types of pathogen ?
Viruses
Bacteria
Fungi
Protists
What are viruses ?
Viruses are tiny, non-living (do not contain cells) particles that can reproduce rapidly within the body.
They invade host cells and use them to make new virus particles.
Once the new viruses are made, they cause the cells to burst.
The cell damage makes us feel ill.
What are bacteria ?
Bacteria are small living cells that either damage cells directly or by producing toxins (poisons).
Bacteria can reproduce rapidly in the appropriate conditions: warm, moist areas with a good supply of oxygen.
The toxins released by bacteria can damage cells and tissues, making us feel ill.
What are fungi ?
Fungi are single-celled organisms that have a body made up of hyphae (thread-like structures).
The hyphae are able to grow and penetrate tissues, such as human skin or the surface of plants.
The hyphae produce spores that can spread to other plants and animals.
What are protists ?
Protists are single-celled eukaryotic organisms (they have a nucleus).
Many are parasites, meaning that they live on or inside other organisms.
They are often transferred to the host organism by a vector, such as an insect or mosquito.
They make us feel ill by damaging our tissues.
What are ways that diseases spread ?
Vectors Body fluids Air Orally (by mouth) Sex Water
How is malaria spread ?
Malaria is a protist that is spread by an animal vector; mosquitoes
How are Ebola and HIV both spread ?
through direct contact with someone else’s body fluids (such as blood).
HIV can also be passed on through pregnancy, birth and breastfeeding.
How does air spread pathogens ?
Some pathogens are released into the air inside droplets when an organism coughs or sneezes. These droplets can then be inhaled (breathed in) by other organisms.
Tuberculosis bacteria are spread in this way.
How is helicobacter spread ?
Helicobacter (which causes stomach ulcers) is spread through oral transmission (passing by mouth) of bacteria from vomit or faeces
What are Diseases that are spread through sexual contact called ?
Diseases that are spread through sexual contact (often simply genital to genital contact) are called sexually-transmitted infections (STIs).
What can stop the spread of STIs ?
Physical barriers (such as condoms) are very effective at stopping the spread of STIs.
What does chlamydia do ?
Chlamydia is a bacterial infection that causes infertility and often has no other symptoms, so easily spreads.
How can you prevent the spread of STIs ?
Testing and treatment with antibiotics prevent spread.
How is Cholera spread ?
Some pathogens contaminate water supplies. Pathogens can infect organisms that drink this contaminated water.
To survive and replicate, what do viruses invade ?
they invade host cells (animals or plant cells)
How do viruses replicate ?
The virus particle inserts its own DNA into the host cell’s DNA, which is then copied and used to make more viruses.
Once the new virus particles have been synthesised (made), what do they cause the cell to do ?
they cause the cell to burst.
This releases the new viruses to invade more cells.
This cell damage makes us feel ill.
How do viruses reproduce? How does this make us feel ill?
To survive and replicate, they invade host cells (animals or plant cells).
The virus particle inserts its own DNA into the host cell’s DNA, which is then copied and used to make more viruses.
Once the new virus particles have been synthesised (made), they cause the cell to burst, releasing the new viruses to invade more cells.
The cell damage makes us feel ill.
What are three diseases caused by viruses?
Ebola
HIV
Measles
What fever does Ebola virus cause ?
The Ebola virus causes hemorrhagic (affects blood vessels) fever.
How is Ebola spread ?
Ebola spreads through body fluid. This can be because of direct contact or though contaminated objects, such as bedding.
How is HIV spread ?
HIV is spread by sexual contact or the exchange of body fluids (e.g blood from sharing needles).
What happens to the body when you have HIV ?
At first, HIV causes a flu-like illness. But unless antiretroviral drugs are used successfully, the HIV virus enters the lymph nodes and attacks the body’s own immune cells.
HIV causes AIDS. AIDS is the name given to the life-threatening infections that can happen when a person’s immune system has been badly damaged by HIV.