yr 9 body at war Flashcards
Disease
Any change that impairs the function of an individual in some way and causes harm to them.
Infectious disease
A disease that can be spread from one organism to another and is caused by a pathogen.
Vector
An organism that carries a pathogen between other organisms without being affected by the disease the pathogen causes.
Pathogen
A disease producing organism.
Host
Organism living in a relationship with another organism. The host provides something needed by the other organism (called the parasite)
Parasite
Organism that lives in or on another organism. The parasite benefits while usually harming the host organism.
Plague
Contagious diseases that spread rapidly through a population and results in a high death rate.
Epidemic
A disease affecting a large number of people in a particular area in a relatively short period of time
Pandemic
A disease occurring throughout the country or continent or worldwide.
Virus
A non-cellular pathogen.
Bacteria
Single celled organism. Can be a pathogen.
Fungi
Organisms, eg mushrooms and moulds, that help decompose dead or decaying matter. Many are parasites and this can lead to disease.
Body’s lines of defence
The way the body reacts to invading pathogens. There are 3 lines of defence, each acting in a different way.
Inflammation
A reaction of the body due to an infection, commonly shown by heat, redness, swelling and pain. (It is part of the 2nd line of defence.)
Phagocytes
A white blood cell that eats and destroys foreign particles, bacteria and other cells in the body. (It is part of the 2nd line of defence.)
Antigen
A substance that stimulates the production of antibodies.
Antibodies
Proteins that are produced by the body, as a result of the presence of a foreign substance in the body and act to get rid of it
Lymphocytes
Small white blood cell present in lymph tissue and circulating in lymph and blood. They combat microbes, fight cancers and neutralise toxic chemicals. (There are T and B lymphocytes. These are part of the 3rd line of defence.)
Immunity
Resistance to a particular disease-causing pathogen.
Ways Diseases can be transmitted
- sneezing
- coughing
-vectors
-contaminated objects
-water supplies
-physical contact
Active Immunity
When your body makes antibodies to a specific antigen.
Passive Immunity
When you receive antibodies from an outside source.
Diseases caused by Viruses
-AIDS
-Common cold
-Ebola
Diseases caused by Bacteria
-Sepsis
-Pneumonia
-Urinary tract infections (UTI)
Diseases caused by Fungi
-Candidiasis
-Cryptococcosis
-Aspergillosis
Diseases caused by Animal Parasites
-Chagas disease
-Leishmaniasis
-Malaria
What was the Bubonic Plague?
The bubonic plague is caused by the bacteria Yersinia pestis. It can spread through contact with infected fleas.
Symptoms include swollen lymph nodes, which can be as large as chicken eggs, in the groin, armpit or neck. They may be tender and warm.
What is the Spanish Flu?
It was caused by an H1N1 virus with genes of avian origin.
Symptoms:
-muscle and joint pain
-headache
-dry throat
-chest pains
-an unproductive cough.
First line of defence
Designed to prevent the entry of invading pathogens.
Second line of defence
Phagocytes engulf and destroy pathogens, this is called phagocytosis.
Third line of defence
Your lymphatic system contains lymph vessels, lymph nodes, lymph and white blood cells. Some of these white blood cells are
lymphocytes.
Physical barriers
Physical barriers play an important role in preventing microbes from reaching tissues that are susceptible to infection (tissue and blood infection).
Examples:
-skin
-cilia
-nasal hairs
-tears
-mucus
Chemical barriers
Chemical barriers destroy pathogens on the outer body surface, at body openings, and on inner body linings.
Examples:
-sweat
-mucus
-tears
-saliva
B lymphocytes
A type of white blood cell that makes antibodies. B lymphocytes are part of the immune system and develop from stem cells in the bone marrow.
T lymphocytes
A type of white blood cell. T lymphocytes are part of the immune system and develop from stem cells in the bone marrow. They help protect the body from infection and may help fight cancer.
Non-specific defence against disease
Nonspecific protective mechanisms repel all microorganisms equally, while the specific immune responses are tailored to particular types of invaders.
Specific defence against disease
Natural barriers include the skin, mucous membranes, tears, earwax, mucus, and stomach acid.
How does inflammation, fever and phagocytosis help with your health?
Inflammation, fever and phagocytosis are signs that your second line of defence has been triggered.
Explain how specific immunity against a particular pathogen is acquired
A vaccination is a specific immunity…
By getting a vaccination, you are exposing your body to the antigen required to produce antibodies specific to that virus, and acquire a memory of the virus, without experiencing illness. Some breakdowns in the immunological memory system can lead to autoimmune diseases.
