topic 3 - infection & response Flashcards
What is a communicable disease?
A disease that can spread from one organism to another
What is a non-communicable disease?
A disease that cannot be spread from one organism to another (e.g. cancer)
What is a pathogen?
A microorganism that enters the body and causes disease
What is a bacterium?
A very small, prokaryotic pathogen that reproduces rapidly inside the body and produces toxins (that damage cells)
What is a virus?
A virus is NOT A CELL. It reproduces rapidly in the cells by replicating itself using the cell organelles - eventually causing the cell to burst.
What is a protist?
A single-celled eukaryote that is usually a parasite. It lives inside other organisms and can cause them damage (transferred by a vector)
What is a vector?
A vector is an organism that can carry a parasite or protist and spread it without getting the disease itself
What are fungi?
They are single-celled pathogens that have a body made up of hyphae (thread-like structures) which can grow and penetrate human and plant tissue. Spread via pores that are produced.
How are pathogens spread?
- Water [cholera]
- Air [influenza]
- Direct Contact [athlete’s foot]
- Bodily Fluid Exchange [HIV]
What is Measles?
Spread: Droplets (sneeze or cough)
Symptoms: - Red Skin Rash
- Fever
Result: - Pneumonia (lung infection)
- Encephalitis (brain infection)
VACCINATION AVAILABLE
What is HIV?
Spread: - Sexual Contact
- Bodily Fluid Exchange
Symptoms: Flu-like symptoms that take years to show
Treatment: Antiretroviral Drugs prevent virus replication
Result: - Immune Cells Attacked
- Body can’t cope with other
infections or cancers [AIDS]
What is Tobacco Mosaic Virus?
Spread: - Direct Contact
- Close Proximity (soil)
Symptoms: - Mosaic Pattern on Leaves
- Leaves discolour
Treatment: - Destroy the plants
Result: - Photosynthesis not effective
- Plant Growth slows down
What is Rose Black Spot?
Spread: - Water & Wind
Symptoms: - Purple & Black Spots
- Leaves turn yellow & fall
Treatment: - Fungicides
- Leaves stripped &
destroyed
Result: - Lack of Photosynthesis
- Growth decreases
Examples of Viral Diseases
- Measles
- HIV
- Tobacco Mosaic Virus
Example of Fungal Disease
- Rose Black Spot
Examples of Bacterial Diseases
- Salmonella
2. Gonorrhea
Example of Protist Disease
- Malaria
How do you prevent disease?
- Being Hygenic
- Destroying Vectors
- Isolating Infected Individuals
- Vaccination
What are the two types of white blood cells?
- Phagocytes
2. Lymphocytes
How do Phagocytes work?
PHAGOCYTOSIS
- Phagocytes detect foreign body
- Phagocytes then engulf the foreign
bodies - The phagocytes then display the
antigens of the foreign body on their
surface for the lymphocyte to detect
them and produce antibodies
How do lymphocytes fight pathogens?
1. The lymphocytes detect the antigens
on the surface of the pathogens
2. They then produce specific
antibodies that attach to the
pathogen antigens and prevent
functions of the pathogenWhat is the name of the cell that remembers antibodies in relation to specific pathogens?
Memory Cells [WBCs]
How do vaccines work?
- First dose of weakened pathogen is given to the patient
- The lymphocytes begin to produce antibodies to attack the pathogen
- After 12 weeks (approx.), a second dose is given to the patient
- This makes sure there are enough memory cells that can counter-act the pathogen if it enters the body in the future.
The whole process is known as IMMUNISATION
What are the pros and cons of vaccines?
Pros:
- Help control many communicable diseases (i.e. measles, mumps, etc.)
- Can prevent epidemics as there is “herd immunity”
Cons:
- They don’t always work
- Occasionally some may have a bad reaction to vaccines (seizure or anaphylaxis)
