Module 1C Flashcards
What are infectious diseases caused by?
Pathogens - disease causing microorganisms.
Explain how pathogens are able to cause symptoms of an infectious disease.
They can directly damage host cells when they are replicating or produce toxins.
Each pathogen has what on its surface?
Specific antigens.
Because each pathogen has specific antigens what are needed to combat the spread of disease?
Specific antibodies.
How exactly do antibodies combat disease?
A type of white blood cell (lymphocyte) will recognise antigens on the surface of pathogens as foreign and will then produce antibodies specific to that antigen.
Each antibody has a unique binding site shape that will be able to lock onto the shape of the antigen.
The antibodies then are able to destroy the pathogen which is then engulfed and digested by macrophages.
What else do white blood cells produce to help fight disease?
Antitoxins
How come if someone has a disease once, they are unlikely to get it again?
B and T cells create memory cells. These are clones of the specific white blood cells that have remained in the body and carry information about past diseases and have the ability to rapidly produce the necessary antibodies.
In what other ways is the body designed for defence against pathogens?
1) Skin is a barrier to pathogens
2) Blood clotting prevents entry of pathogens
3) Mucus in airways traps pathogens
4) Hydrochloric acid in the stomach kills pathogens
What are the four types of pathogens and what do they cause?
Fungi - athletes foot
Protozoa - dysentery
Bacteria - Cholera
Viruses - flu
What is the difference between a non-infectious and an infectious disease?
An infectious disease can be passed from one person to another easily whereas a non-infectious disease can not.
What is passive immunity?
It is when you are given or PASSED someone else’s antibodies.
What is active immunity?
It is when your body will make its own antibodies.
Explain the process of immunisation.
A harmless pathogen that still contains the antigen proteins on its surface is injected into the patient.
Antigens trigger the normal response of the lymphocytes to produce those specific antibodies.
Immunity will remain because of the memory cells.
What are the benefits of immunisation?
Stops you from getting ill and if most people are immunised the disease will be less likely to spread.
What are the risks of immunisation?
It’s mostly the short-term side effects; swelling at the injection site, redness, muscle ache and feeling ill for a while after.
