Human Communicable Disease Flashcards
What makes something a pathogen?
A microorganism must:
-gain entry to the host
-colonise the tissues of the host
-resist the defences of the host
-cause damage to the host tissues
What are pathogens?
Pathogens are microorganisms that cause infectious diseases
What do bacteria release?
Poisons or TOXINS
How can bacterial infections be treated?
Antibiotics
What diseases are cause by bacteria?
-food poisoning
-cholera
-typhoid
-whooping cough
-gonnorhoea
Which pathogen is smaller, viruses or bacteria?
Viruses
How do viruses damage the body?
-reproduce inside host cells
-burst the host cell open
-destroys cell
What are antibodies?
specific molecules produced by lymphocytes that bind to antigens
What are Antibiotics
drugs made by fungi that kill, or prevent the growth of bacteria
What is an antigen?
unique molecules on the cell surface of pathogens
What is an antitoxin?
a substance produced by lymphocytes that neutralises toxins produced by bacteria
What is a phagocyte?
a type of white blood cell that engulfs pathogens to destroy them
What are pathogens?
microorganisms that cause infectious disease
What is in a vaccine?
dead or inactive pathogenic material used in vaccination to develop immunity to a disease in a healthy pers
What is a lymphocyte?
a type of white blood cell that can produce antibodies and antitoxins
Give examples of pathogens
Virus
Bacteria
Fungi
Protists
What happens in virus replication?
• The virus injects DNA into the host cell
• The host cell uses the viral DNA to produce viral proteins
• The viral DNA replicates
• New viruses are produced
• The host cell is destroyed and viruses are released
• The new viruses then attack other cells.
What is an STD?
A sexually transmitted disease
What is a communicable disease?
A disease that can be spread from person to person
What is a non-communicable disease?
A disease that cannot be spread from person to person
What is malaria?
• A disease transmitted by mosquitoes
• It is caused by a single celled parasite called Plasmodium, a protocist
What groups of people are most at risk to disease?
• Infants
• Children under 5
• Pregnant women
• Those who are HIV positive
What is the life cycle of Plasmodium?
• First of all, a mosquito bites a human who is infected with malaria.
• It sucks up human blood containing the Plasmodium parasite
• Then if the mosquito bites another person they get the parasite
injected into their bloodstream
Why is malaria difficult to treat?
-The disease has many different phases when the parasites are in the
bloodstream/inside the liver/inside red blood cells
-it is difficult to develop drugs to treat it as the parasites
are sometimes hidden inside the body cells.
-most drugs would only target one form of the parasite and
would leave other forms untouched.
-The parasite has developed resistance to many of the anti-malarial
drugs.
Give some Symptoms of malaria
Headache
Fever
Chills
Sweats
Dry cough
Nausea
Vomiting
Fatigue
What are antibiotics?
• Drugs that kill bacteria inside your body without damaging
body cells
What are antiseptics!
Substances used on living surfaces to
destroy microorganisms
What are disinfectants?
Substances used on non-living surfaces to
destroy microorganisms
What is the name of the specific
procedures used to prevent unwanted
microorganisms from contaminating the clinical specimen?
Aseptic technique
Bacteria multiply by splitting in two. How fast do bacteria grow?
Once every 20 minutes
Why do we seal the Petri dish with sticky tape?
-To reduce the evaporation or drying of the agar
-Nothing from outside can get in
What are antibodies?
Proteins produced in the body in response to a
specific antigen as part of the immune response.
What are white blood cells?
Blood cells that help the human immune
system fight infection and disease (
examples are lymphocytes and phagocytes)
What is an antigen?
An antigen is a marker (like a
protein flag) that tells your
immune system whether
something in your body is harmful
or not.
The antigens on pathogens are
very different to the antigens that
cover our human body cells
They signal to your white blood cells in the immune system to
produce an immune response. Every cell has its own specific
antigen to tell the body what it is, for example bacteria, viruses,
cancer cells, every human body cell from different location
How can white blood cells destroy pathogens?
They can engulf pathogens and destroy
them
• They can produce specific antibodies to
the antigen to destroy them
• They can produce antitoxins that
neutralise the toxins released by the
pathogen
What is in a vaccine?
Dead or inactive pathogens
Who produces the antibodies in active immunity?
The infected person
Who produces the antibodies in passive immunity?
Different person or animal
What are some other key points about active immunity?
Works slowly
Lasts for a long time
Occurs after illness or vaccination
What are some key points about passive immunity?
Works quick
Lasts for a short time
Occurs when a baby recite bee antibodies from mother
Fill the gaps:
The substances made by white blood cells to kill pathogens are called …………………………………. .
The substances made by white blood cells to counteract poisons produced by
pathogens are called …………………………………. .
Medicines which kill bacteria are called …………………………………. .
Antibodies
Antitoxins
Antibiotics
