B2 Keeping Healthy Flashcards
Key words
Pathogen Communicable Non communicable Virus Bacteria Fungi Protests Microorganisms
Communicable means….
….can be passed from person to person.
Examples of communicable diseases
Cold Conjunctivitis Flu Ebola HIV
Non communicable means….
…..can’t be passed from person to person and is usually genetic.
Examples of non communicable diseases
Cystic fibrosis
Malaria
Type 2 diabetes
Cancer
Pathogen means….
…a bacterium, virus or microorganism that can cause disease
Virus are….
….really tiny (about 1/100th the size of bacterium). They replicate themselves inside the infected organisms cells. These cells them burst releasing the viruses
Bacteria are…
…..very small cells (about 1/100th the size of your body cells), which can reproduce rapidly. They make you feel ill by producing toxins (poisons) that damage your cells and tissues.
Protists are….
….these are eukaryotic (have a nucleus), usually single called and vary in size.
Fungi are…
….some fungi are single celled, while others have a body made up of a thread like structure called hyphae. These hyphae can grow and penetrate human skin and the surface of plants causing diseases. They can also produce spores which can be spread to other plants and animals.
Microorganism means…
…..a very small organism such as a virus, bacterium or fungus.
What physical defences does the body use to prevent infections?
The skin
Blood clotting
Mucous membrane and cilia
How the skin help to prevent infection?
The skin covers the whole body. It protects the body from physical damage, microbe infection and dehydration.
How does blood clotting help to prevent infections?
Blood clots stop you losing too much blood, and help to prevent microorganisms getting in. This is aided by platelets. (Platelets in the blood clump together to plug the wound.)
How does mucous membrane help the body prevent infection?
The respiratory tract (nasal passage, trachea and lungs) is lined with mucous and the cilia (hair like structures). The mucous stops particles that could contain pathogens and the cilia wafts the mucous up to the back of the throat where it can be swallowed .
What chemical defences does the body use to prevent infection?
Tears
Saliva
Stomach acid
How does the body use stomach acids to prevent infections?
Hydrochloric acid in the stomach kill harmful microorganisms that might be in the food and drink we ingest.
How does the body use tears to prevent infections?
Eyes produce an enzyme called lysozyme which breaks down bacteria on the surface of the eye.
How does the body use saliva to prevent infection?
Saliva produced in the mouth, contains molecules which kill pathogens that enter the mouth so they don’t reach the stomach.
What 3 defences does the body use to prevent infection?
Physical
Chemical
Microbial
What are microbial defences?
Some pathogens manage to make it past saliva in the mouth and the acid in the stomach and enter the gut. Here they have to compete with bacteria which naturally live in the gut (intestines) in order to survive.
Give an example of a virus in an animal
Flu
Give an example of a virus in a plant
Tobacco mosaic virus
Give an example of bacteria in an animal
Food poisoning (Salmonella )
Give an example of bacteria in a plant
Crown gall disease
Give an example of a fungi infection in an animal
Athletes foot
Give an example of a fungal infection in a plant
Ash die back
Give an example of an infection caused by Protists in animals
Malaria
Give an example of an infection caused by Protists in a plant
Potato blight
