Health and Disease B6 Flashcards
What is a disease?
A disease is a condition that impairs the normal functioning of an organism, both plants and animals can get diseases.
What are some causes of disease?
The organism may become infected by a pathogen. There may be a mutation in the organisms genes, or the organism may be affected by environmental conditions, e.g. if a plant doesn’t get enough light, it won’t grow properly.
What is a pathogen?
A pathogen is a type of microorganism that causes disease. Types of pathogen include bacteria, viruses, protists and fungi.
What is a communicable disease?
A communicable disease is a disease that can be spread between organisms. They are caused by pathogens infecting the organism e.g. malaria is caused by a protist.
What is a non-communicable disease?
Non-communicable diseases cannot be passed from one organism to another, e.g. cardiovascular and respiratory diseases, cancers and diabetes. They generally last a long time and progress slower. They are often linked to unhealthy lifestyles.
How can one disease lead to another?
HIV stops the immune system from working properly. The bacteria that cause another communicable disease tuberculosis are normally destroyed by the immune system before symptoms can develop. But if the tuberculosis bacteria infect someone with HIV, the bacteria are not destroyed therefore the diseases progress very rapidly, this means people with HIV are more likely to show symptoms of tuberculosis, it’s also much harder for them to recover from tuberculosis.
How are communicable diseases spread?
Communicable diseases are caused by pathogens.
Describe a bacteria pathogen.
Bacteria are very small cells which reproduce rapidly and make you feel ill by producing toxins that damage your cells and tissues.
Describe a virus pathogen.
Virus pathogens are not cells. They are really tiny and they replicate inside the infected organism’s cells then burst and release the viruses.
Describe a protist pathogen.
Protists are eukaryotic and usually single-celled. Protists that cause disease are often parasites.
Describe a fungi pathogen.
Some fungi are single-celled whilst others have a body, which is made up of thread-like structures called hyphae. These hyphae can grow and penetrate human skin and the surface of plants causing diseases. They can also produce spores.
What is an example of a disease being spread through water?
Cholera can be spread through bathing in or drinking dirty. It causes diarrhoea and dehydration.
What boosts the spread of diseases?
The transmission of communicable diseases increased when lots of people live crowded together in a small space because it’s easier for pathogens to pass from one person to another. Poor diet also increases the risk of infection because the immune system can be weakened by not getting the right nutrients and the risk of infection increases when there is limited access to healthcare.
What can be done to reduce the spread of disease?
Basic hygiene, destroying vectors - getting rid of organisms that spread disease means you prevent the disease from being passed on. Vaccination - helps against communicable diseases and it means they can’t develop the infection and pass it on
What is a vector?
Vectors are organisms that carry and pass on disease between different species.
