B1 - Staying healthy Flashcards
Why are babies feeding bottles sterilised?
To get rid of any microorganisms which cause disease.
What are pathogens?
A pathogen is something that can cause a disease.
What are the four types of pathogen?
- fungi
- bacteria
- viruses
- protozoa
What does contagious mean?
Contagious is when a disease spreads directly from person to person.
How are pathogens prevented from entering the body?
- skin stops entry
- hydrochloric acid in stomach kills pathogens
- sticky mucus lines mucus membranes in breathing system trapping them
- blood clots seal wound preventing entry
What are vectors?
Vectors carry microorganisms that cause diseases but do not suffer from the disease themselves.
What is a parasite?
An organism which lives in or on another organism (its host) and benefits by deriving nutrients at the other’s expense
What is the difference between benign tumours and malignant tumours?
Malignant tumours move around the body and are cancerous whereas benign tumours are usually harmless.
What do white blood cells do?
- surround and engulf pathogens such as bacteria
- make antibodies that stick the pathogens together
What is active immunity?
The immunity which results from the production of antibodies by the immune system in response to the presence of an antigen.
What is passive immunity?
The short-term immunity which results from the introduction of antibodies from another person or animal.
Which type of pathogens can be controlled by antibiotics?
Bacteria.
What type of pathogen is controlled by antivirals?
Viruses.
What is the difference between antibiotics and antivirals?
Antibiotics destroy the pathogen whereas antiviral drugs slow down the pathogen’s development.
What does the body react to when it is infected?
- antigens on the surface of a foreign invader
- toxins that are produced by pathogens
- damage to his cells caused by the pathogen
What is an antigen?
A toxin or other foreign substance which induces an immune response in the body
What are the two types of white blood cell?
- phagocytes
- lymphocytes
What do phagocytes do?
- ingest and absorb the pathogens or toxins
- release an enzyme to destroy them
What do lymphocytes do?
When a lymphocyte with the appropriate antibody meets the antigen, the lymphocyte reproduces quickly to make many copies of the antibody that neutralises the pathogen.
What is a placebo?
A dummy pill.
What is a blind trial?
A blind trial is where a patient does not know whether they are receiving medication or a placebo.
What is a double blind trial?
A double blind trial is where neither the patient or the doctor know who is receiving a placebo and who is receiving medication.
Why are placebos rarely used in human trials?
Many doctors do not like giving patients with a disease a placebo. They feel the patient will not benefit from taking a fake drug, and will not get better. They do not think this is fair to the patient.
