U2T2 - Infectious Disease Flashcards
Define Disease
Any condition impairing the normal function of an organism
What is a Pathogen?
An infectious agent that passes between individuals causing disease.
What are the characteristics of a non-infectious disease
Not caused by pathogens and not passed between people.
T or F: Mutations are a type of infectious disease
False - mutations are non-infectious
What are mutations?
Incorrect formations of gametes
What are the 3 types of Non-infectious disease?
Mutation, Nutritional, environmental
T or F: Diabetes 2 is a type of nutritional disease
True
What is an example of environmental non-infectious disease?
Chemicals, radiation
What are the characteristics of an infectious disease?
Caused by pathogens
What are the 2 types of pathogens?
Primary pathogens, opportunistic
T or F: Opportunistic pathogens cause disease whenever they are present.
False - Opportunistic pathogens cause disease when the host’s defenses are weakened.
What are the 2 classes of diseases
Cellular (living) and Acellular (non-living)
What are the 4 types of cellular diseases?
Bacteria, Fungi, Protists, Parasites
T or F: Bacteria is pathogenic
True
What do fungi entail/are made of?
Molds, yeast
What are protists?
Diverse organisms that cause disease, from multicellular to unicell
T or F: Parasites live off their host
True
What are the 2 types of parasites?
Endoparasite, ectoparasite
T or F: Ectoparasites live on the inside of their host?
False - Ectoparasites live on the outside of their host
What are the 2 types of Acellular diseases?
Virus and Prions
What are the characteristics of a viruses?
Diseases that cannot reproduce on their own and has its DNA enclosed in a protein shell
T or F: Priors is similar to mutations
True - both are a form of poor replication
What are prior diseases?
Abnormal forms of protein that cause neurodegenerative diseases
Define Contagious?
The act of transmission through direct contact
Describe virulence
The ability of a pathogen to cause disease
T or F: Carriers remain infectious and can be ill/sick
False - Carriers remain infectious but are not ill/sick
What is the incubation period?
The time between the infection and onset of disease/symptoms
What is pathogenesis?
Biological mechanisms leading to diseased states
Define virulence factors
Factors helping pathogens invade hosts, cause disease and evade defences
Name the 5 virulence factors
Adherence factors, invasion factors, capsules, toxins, lifecycle changes
What is the reason of the adherence factors?
The mucus present on cell walls is removed regularly, meaning the pathogens must adhere to the cells and multiply before swept away
What are 3 invasion factors?
Surface components, enzymes to damage host tissue, enzymes to breakdown immunglobin
Why do capsules affect virulence?
Act as protection for pathogen DNA, resistant to phagocytosis
Define toxins
chemical substances negatively impacting biofunction of host
What are the 2 types of toxins
Endotoxins and exotoxins
T or F: Endotoxins are on the inside of bacteria
False - Endotoxins found on outside of the bacteria
What do exotoxins do?
Produce protein toxins and enzymes to destroy host defences
What are antigens?
Molecules eliciting immune responses
What are the 2 classifications of antigens?
Self or Non-self
Where are antigens found?
On the surface of cell membranes
T or F: Self antigens elicit an immune response
False - self-antigens do not elicit an immune response
T or F: Non-self antigens are foreign to the body
True
T or F: Red Blood Cells possess basic antigen capacities
True
What do A, B, AB, and O blood types refer too?
The type of glycoproteins/antigens present on the Red Blood Cells
What are antigens with overreactions to no danger called?
Allergens
T or F: antigens carry toxins to elicit immune responses
True
How many lines of defence are their against pathogens?
3
What is the first type of barrier against pathogens?
Physical/chemical barrier e.g. hair, mucus
What is the 2nd type of barrier against pathogens?
Non-specific (innate) e.g. leukocytes, phagocytosis
T or F: the 3rd type of defence is innate
False - the 3rd type of defence is adaptive/production of antibodies
What is innate immunity?
Immune responses with no immunological memory
What are the characteristics of innate immunity?
Non specific, rapid, all animals, fixed responses, no immunological memory
T or F: Innate immunity is specific, meaning it targets specific antigens
False - Innate immunity is non-specific, meaning it doesn’t target specific antigens
What do complement proteins do?
When activated trigger cascades of other complement proteins and attract phagocytic cells, cause holes in bacterial membranes
What is the role of cytokines?
Signal in response to cell damage and pathogen presence, activate lymphocytes and macrophages
Where are leukocytes found?
In blood and tissues
What do leukocytes do?
Receptors to recognise pathogenic patterns.
T or F: Prostaglandins cause vasodilation which leads to heat, redness, swelling and pain
True
What releases prostaglandins
Physical and chemical agents
T or F: Prostaglandins can be similar to hormones
True
What does histamine do?
Boosts blood flow which increases concentration of innate immunity components
How many types of leukocytes types are there?
8
T or F: the majority of leukocytes perform phagocytosis
True
What do natural killer leukocytes produce?
cytotoxic chemicals and cytokines
What is adaptive immunity?
Immunity that is specific and involves immunological memory
Define lymphocytes?
Types of white blood cells formed in bone marrow
What are the 2 types of lymphocytes
Humoral (b-cells) and Cell mediates (t-cells)
What do B-cells do?
Produce antibodies
What are the 4 types of T-cells
Helper, cytotoxic, memory and regulartory
T or F: helper t-cells produce cytokines
True
What type of t-cells kill foreign antigens?
Cytotoxic
What do memory t-cells do?
Antigens that are specific that persist after infection
T or F: regulatory t-cells secrete cytokines
False - Regulatory t-cells suppress the immune response
What are antibodies?
Immunoglobins that are specific to antigens
How do B-cells work?
They bind to antigens and create antibodies specific to that antigen
What are the functions of antibodies?
Neutralisation of toxins, agglutination (binding antigens together and activation phagocytosis)
How are antigens recognised?
Helper t-cells are activated by macrophages, which then activate b-cells or more t-cells
What is humoral immunity?
B-cells being triggered and binding to antigens with antibodies
The first encounter with an antigen is the primary immune response, what remains after this encounter?
Memory B-cells and T-cells
What are all encounters called after the first one?
Secondary immune responses
How is passive immunity built?
It is based down in the placenta/birth, it is short lasting
T or F: Active immunity is built from natural exposure
True
What is Artificial passive immunity
Infected with antiserum that holds specific antibodies, normally after birth
How is active immunity achieved artificially?
Infected with vaccines that hold the antigen, therefore artificial exposure.
What is the concept of herd immunity?
If enough people are immune/vaccinated, then pathogen cannot spread
What are some examples of disease transmission medians?
Water, poo, direct/skin contact, air transmission
What is the definition of direct contact transmission?
From Human direct to human
T or F: A person getting sick from a petting zoo is direct contact transmission?
False - indirect contact transmission
T or F: Speed and intensity of disease transmission is linked to transport hubs?
True
Name 4 factors affecting immunity/transmission?
Lifecycle of pathogens, transmission factors, herd immunity concentration, mobility/travel of infected.
What is the rating scale used to rate transmission?
Amount of people infected from 1 person
What does R5 mean?
Means it is expected 5 people will be infected by this disease per infected person.
T or F: Bad hygiene improves disease spread?
True
Name some examples of good hygiene practices.
Washing hands, avoid coughing, cleaning common items
T or F: 50% of infections involve transmission through hands.
False - 80% use transmission through legs
What is contact tracing?
Following an infected persons actions and visited places to follow spread of disease.
T or F: closing schools/workplaces improves disease spread?
False - hinders it
T or F: Temperature screening provides early indicators of disease?
True
What is the most effective controlling measure of disease spread?
Quarantine
T or F: Reduction of mass gatherings reduce disease spread??
True
What do neutrophil leukocytes do?
Phagocytosis, releases antimicrobial compounds, attracts immune cells
What do Macrophage leukocytes do?
phagocytosis, releases cytokines, present antigens
What do monocytes leukocytes do?
phagocytosis
What do dendritic leukocytes do?
phagocytosis, have large SA, present antigens
What do basophils leukocytes do?
Release histamine, limited phagocytosis
What do Eosinophil leukocytes do?
Present antigens, produce cytokines, perform limited phagocytosis, largely focus on parasites
What do mast leukocytes do?
Handle inflammation, vasodilation, produce histamines, limited phagocytosis
What do natural killer leukocytes do?
Recognise/identify virus/cancer cells, produce cytotoxic chemicals, produce cytokines
