Y12 Immune System T1 Flashcards
What are communicable or infectious diseases? (transmissible diseases)
Diseases caused by foreign organisms invading the body and multiplying there
What is a pathogen?
A disease causing organism often referred to as a pathogenic organism
What does it mean if a disease is contagious?
If they are passed on by direct contact with a person suffering from a disease, or by contact with something touched by the person
What are vectors ( in relation to the spread of pathogens)?
An agent such as an insect capable of transferring a disease causing organism from one person to another
Infectious diseases are caused caused by invasion of pathogens in the form of?
Bacteria and viruses mainly but also fungi and animal parasites
Ways that transmission of pathogens can occur?
direct and indirect contact, transfer of body fluids, disease-specific vectors, contaminated food and water
What are bacteriophages?
Viruses which multiply in bacterial cells causing death to the bacterium
5 diseases caused by bacteria?
Chlamydia, Cholera, Gonnorrhoea, Dental caries (tooth decay), Leprosy Pneumonia
5 diseases caused by viruses?
HIV/AIDS, Bird flu, Chickenpox, Herpes, Colds, Ebola
A diseases caused by fungi?
Ringworm
Some diseases caused by animal parasites?
Malaria, roundworms, lice
How can diseases be transferred?
Direct Transmission by touch Transmission by bodily fluids Waterborne transmission Ingestion Airborne transmission Transmission of vectors
2 forms of transmission by contact?
(Touching an Infected person) or indirect (touching an object that has been touched by an infected individual)also known as finite transmission
How is disease spread by Transmission of bodily fluids?
through blood or other mucus membranes ( from nose, mouth, throat, genitals) eg. HIV, hepatitis b & c
How can spread of disease occur from Infection by droplets? Water Bourne.
droplets of moisture w/ pathogenic organisms are emitted when breathing, talking, sneezing or coughing eg. Influenza
How can disease be transferred via ingestion?
food or drink contaminated eg. Salmonella
How can airborne transmission cause spread of disease?
Airborne transmission- moisture in exhaled droplets carry viruses and some bacteria
How can disease be transferred by transmission by vectors?
transfer of pathogens by other animals such as insects, ticks or mites. Some transfer directly others ( house flys) via food and water.
Difference between specific defences and non specific?
Non specific- (first line) prevent entry, (second line) destroy pathogens if they enter
Specific-( third line) specialised lymphocytes target specific pathogens to destroy and remove from the body)
What is immunity?
Resistance to infection from invading microorganism
What is the immune system?
Different types of cells that occur in most organs of the body and that protect against foreign organisms, alien chemicals and abnormalities
What is an immune response?
A response triggered by foreign substances or microorganisms entering the body
What is a self antigen?
Any large molecule produced in a persons own body; does not cause an immune response in that person
What is a non self antigen?
Any compound foreign to the body that triggers an immune response
What are the physical characteristics of bacteria?
-Single cell, only seen with a microscope
- cell shape is used to classify into 4 catergories
(cocci- circular, bacilli- rods, spirilla - loose coils, vibrio (curved rods)
Modes of action for bacteria?
- Releasing toxins which inhibit/ alter cell activity or poisons which alter metabolism, they may also cause allergic reactions
Endotoxins- released when bacteria die
Exotoxins- released by living bacteria
Physical characteristics of viruses?
Molecules of DNA or RNA wrapped in proteins
Mode of action for viruses?
DNA or RNA induces cell to manufacture more virus particles, attaching to the outside of a host cell allowing the nucleic acid to enter the cell, new virus genes are then produced by the host cells so hundreds of new virus particles are formed
Physical characteristics of fungi?
Multicellular, Eukaryotic
Mode of action for fungi?
Reproduce by spreading microscopic spores, spores often found in air and soil where they can be inhaled or come in contact with body surfaces
Physical characteristics of parasites?
Multicellular, ecto and endo
Mode of action for parasites?
Parasites cause infection by living and multiplying in another organism. This can cause fever, inflammation and other physical problems
Physical characteristics of prions?
Folded protein structure
Mode of action for prions?
Prions are a type of protein that can trigger normal proteins in the brain to fold abnormally
Diseases caused by prions?
Mad cow disease
Physical characteristics of Protozoa?
Moves independently, single cellular
Modes of action for Protozoa?
Produce toxin and multiply inside other cells
Examples of diseases caused by Protozoa?
Malaria