Unit 5 Flashcards
What is a disease
A disease is a disorder that affects an organism’s body, organs, tissues or cells.
Communicable disease
Which are caused by pathogens and can be transferred from one organism to another. In humans, these examples include measles, food poisoning and malaria.
Non communicable diseases
Which are not transferred between people or other organisms. Examples in humans include cancer, diabetes, genetic diseases and conditions, heart disease and neurological disorders. Non communicable diseases are the leading cause of death in the world.
Microorganisms vs pathogens
Microorganisms are small living things that are everehre around us and cannnot be seen with the naked eye. Pathogens are harmful microorganisms taht causes diseases,
Examples of where bacteria are helpful (4)
not all bacteria are harmful. For example, yogurt and cheese makers use bacteria to make their products. Bacteria like intestinal flora can be helpful to our bodies whereas e.coli can be harmful and can cause disease. More importantly, there are millions of bacteria in the human digestive system. Having the right mix of bacteria is vital. Gut bacteria help to digest good. They also help prevent diabetes , obesity and some types of cancer.
Parasite
An organism that lives in or on an organism of another species (its host) and benefits by deriving nutrients at the other’s expense.
Host
A living organism that acts as a harbor for invading pathogenic organism
Lifecycle of a pathogen
They infect a host, reproduce/replicate themselves and spread from their host to infect other organisms.
Four main types of pathogens
Four main types of pathogens are bacteria, virus, fungi and protozoa.
Toxins (as a way of causing disease )
toxins are harmful substances produced by the pathogen that poison the body’s tissue and enzymes.
Reproduction ( as a way of causing disease )
A rise in the number of pathogens can damage a cell, even causing it to burst. Some pathogens hijack resources that the cell needs to survive. Painkillers can relieve the symptoms of an infection but do not kill the pathogen.
Some signs of immune response
Sites of infection often become swollen, sore and hot as a result of increased blood flow.
Antibody
A Y-shaped protein produced by the body that binds to antigens
Antigen
A substance on pathogens that stimulates the production of antibodies
B-lymphocyte
A white blood cell that produces antibodies
Pathogen specific defenses include
Antibodies, T- and B-cells
Non pathogen specific defenses include
Inflammation to attract white cells into tissues and ingestion of bacteria by white blood cells
Immune response
The body’s defense mechanism against foreign material such as pathogens.
Phagocytosis
The process where a type of white blood cell called a macrophage ingests and destroys a pathogen.
T+lymphocyte
A type of white blood cell that recognizes and destroys pathogens, and coordinates the immune response
Vaccine
A small amount of dead or weakened pathogen that stimulates antibody production. A vaccine stimulates the production of antibodies and memory cells against the target pathogen, without making the person severely ill. If the vaccinated person is later infected by the same pathogen, their immune system can destroy it very quickly.
Here immunity
Resistance to the spread of an infectious disease within a population based on pre-existing immunity in a high proportion of individuals as a result of previous infection or vaccination
Epidemic
A widespread occurrence of an infectious disease in a community at a particular time.
Moses’s of indirect transmission
Airborne
Vehicle borne
Vector borne
-Mechanical
-Biological
