Disease/ Immune System Flashcards
What does the germ theory state?
That specific microbes cause specific infectious diseases
What is microbiota?
A microbial community
How does an infection occur?
When a pathogen gains entry to the human body and once within the body starts to multiply
If infection is not fought off by the immune system when does disease begin to occur?
Disease only occurs after body cells and organs are damaged by the infectious microbes and the signs and symptoms of the specific disease are visible
What is the incubation period?
The period after infection before the first symptoms appear
What is asymptomatic carrier?
A person that is infected by a pathogen but in good health and never shows symptoms of the disease.
What are the possible entry points for pathogens?
- nose/ throat
- ducts/ tubes
- mouth
- genitals
What is an example of a bacterial disease?
Pneumonia, tetanus, salmonella
What is an example of a disease caused by a virus?
Influenza, AIDS, Ebola
What is an example of a disease caused by fungi?
Tinea
What is an example of a disease caused by Protozoa?
Malaria
What is an example of a disease caused by prions?
Kuru
What are exclusive extracellular pathogens?
Can only live or reproduce on the surface or in bodily fluids
What are exclusively intracellular pathogens?
Can only live or reproduce within the host cells
What is facultative intracellular pathogens?
Can live and reproduce both in and out of the body
When is a cell said to be diseased?
If a cells normal cellular activity is stopped or changed is it said to be diseased
What is a pathogen?
A disease causing cellular or non cellular agent
What is a parasite?
An organism that lives in or on a host organism, obtaining food, shelter and contributing nothing to the hosts welfare
What is an infection?
An invasion and/ or growth of a harmful agent
What is a carrier?
An individual that is the host of a pathogen that can transmit the pathogen but may not experience any symptoms
What is a vector?
An animal, usually an insect, that transmits the pathogen from host to host
Is bacteria multi or unicellular?
Unicellular
How does bacteria transmit infection within the body?
Releasing toxins in the body and can rapidly reproduce
What is the treatment method for bacteria caused infection/ disease?
Antibiotics
How do viruses reproduce?
In the hosts cells
How are viruses transmitted from person to person?
Airborne or bodily fluids
How are bacterial infections transmitted from person to person?
Touch, consumption, airborne
Can antibiotics treat viruses?
No
What are treatment methods for viruses?
Preventative measures such as vaccines
How are fungi infections transmitted?
Releases toxins
How is fungi growth treated?
Not allowing to spread by reducing moist areas, anti fungi medication
What is a Protozoa?
A single called eukaryotic cell and parasite
How are Protozoas passed on?
Hosts consuming contaminated food and water
What’s an example of a vector for the Protozoa malaria?
Mosquito
What’s an example of an infectious disease caused by Protozoa?
Malaria
How can Protozoa diseases be treated?
Antibiotics (can become resistant)
Controlled by medication
What are prions?
Abnormal proteins that infect neutrons and destroy brain cells by rupturing the cell surface membrane. This causes brain damage and can be fatal
How can prions be transmitted?
Consuming contaminated meat of may occur naturally in some individuals
What is an example of a prion caused disease?
Mad cow disease
What does a virus contain?
DNA/ RNA
Is the first line of defence specific or non specific?
Non specific
Is the 2nd line of defence specific or non specific?
Non specific
Is the 3rd line of defence specific or non specific?
Specific
What barriers make up the first line of defence?
Chemical and physical
Do physical and chemical barriers form memory of pathogens?
No
What are examples of chemical barriers?
Acids, enzymes, mucus, sweat, sebum
Examples of physical barriers?
Intact skin, mucous membrane, cilia, nasal hairs, ear wax
Where is the chemical barrier acid found?
Stomach etc.
Where are the chemical barriers of enzymes found?
Saliva and tears
What are vaccines?
Vaccines contain dead or altered micro organisms etc. that bring about an immune reaction that will activate B cells and generate antibodies
How do vaccines work to build immunity?
Stimulates B memory cells so the host will be immune if the host is infected on a new occasion
What is herd immunity?
A form of immunity that occurs when a significant portion of a population is vaccinated which provides protection for individuals who have not developed immunity
How do plants defend against pathogens?
Tend to be barriers or they isolate the diseased sections to avoid spreading
What are disorders that can occur in the immune system?
Cancers, infections/ infectious diseases, inherited diseases, autoimmune disorders
How can inherited diseases be potentially treated?
Gene therapy
What is an autoimmune disorder?
The loss of the ability to distinguish self from non self, can cause the immune system to attack the cells of the body
What is hypersensitivity?
Refers to an immune system response to an antigen beyond what is considered normal
When do hypersensitivity reactions occur?
When an individual has been sensitised to an antigen
How do antibodies respond to an allergen?
By causing the release of histamine from cells
What is the normal response of the innate immune system to infection?
Acute inflammation
What does acute inflammation do?
Isolates and eliminates invading pathogens
What is immunity?
Resistance to infectious disease
All immune cells are what type of blood cells?
White blood cells
Where are B and T cells located?
Lymph nodes
Where are neutrophils located?
Circuits in bloodstream
Where are macrophages and dendritic cells located?
Bodies entry points such as mucous membranes of the gut, throat and airways
What subgroup are B and T cells apart of?
Lymphocytes
What are lymph nodes the site of?
Where foreign antigen meets B and T cells and activate the immune response to occur
Why do lymph nodes swell when infection occurs?
Because the number of B and T cells increases
When does the adaptive immune system come into operation?
Only if the pathogen overcomes the innate immune system
Primary lymphoid organs are the site of?
Immune cell production and maturity
Secondary lymphoid organs are the sites of?
Immune cell activation by meeting antigens and where the immune system responds
When is the second line of defence initiated?
If the pathogen overcomes the first line
Why does intact skin provide a physical barrier?
Because the epidermis consists of dead skin which sheds preventing entry of pathogens
How does the nasal cavity prevent against pathogens?
Hairs and mucus traps
How does the trachea and bronchi protect against pathogens?
Mucous layer traps
How do the eyes protect from pathogens?
Cleansed by tears which also contain chemical inhibiting bacterial growth
How does the stomach defend against pathogens?
Acid kills many micro organisms
What is normal flora?
The non pathogenic bacteria that normally resides in regions of the body
Do phagocytic cells attack extra or intracellular pathogens?
Extracellular pathogens
What is an example of an extracellular pathogen which can be attacked by phagocytosis?
Bacteria in the blood or tissue
Once pathogens have gained entry to a cell can innate immune cells directly attack them?
No
How are intracellular pathogens destroyed?
Natural killer cells
How do phagocytes eliminate pathogens and cell debris?
Engulf
What is an antigen?
Any molecule or part of a molecule that initiates an immune response
What are self antigens which are located on the surface of cells called?
HLA markers
What are organ and tissue transplants matched?
HLA markers of donors must match recipients
Which is the most abundant white blood cell?
Neutrophils
What do neutrophils do?
Identify and mount phagocytic attack on microbes
What is the role of the natural killer cell?
Eliminate virus infected cells and cancer cells by degranulation
What white blood cells kill viruses?
Natural killer cells
What is the role of macrophages?
Identify and eliminate pathogens by phagocytosis
Which white blood cells are antigen presenting?
Macrophages and dendritic cells
Where are macrophages found?
In almost all tissues
What cells do natural killer cells attack?
Cells lacking self markers
How do natural killer cells destroy infected cells?
Degranulation releases professes and also performing proteins which insert holes in plasma membrane of foreign cells, inducing programmed cell death apoptosis
Where are dendritic cells located?
In tissues including skin, airways and gut
What is the role of the dendritic cells?
Mobile cells that identify pathogens and secrete antiviral cytokines
How do dendritic cells migrate?
Via the lymphatic vessels to lymph glands where they act as antigen presenting cells
What is the role of mast cells?
Releases histamines and other active molecules during acute inflammation, play role in allergies
How do mast cells attract other immune cells to infection site?
Releasing chemical signals
Why is the macrophages location ideal?
Because it’s located at the entry points
Which cells produce antibodies?
Plasma cells
Prions are composed of?
Proteins
Why are there different antigen binding site on different antibodies?
Because of the result of pathogens that infect a host
A non self antigen would be found on
A pathogen
Monoclonal antibodies used to treat cancer are a form of
Passive immunity
What is a cellular response that could directly lead to inflammation?
Macrophages releasing cytokines
What is a chemical barrier that prevents the entry of pathogens into a host plant?
A waxy secretion on the surface of leaf epidermal cells
What cells does the disease HIV attack?
Helper cells
A sequence of events that lead to acquired immunity would be naive…
B cells differentiating into plasma and memory B cells
The vaccination to protect individuals against whooping cough and tetanus is an example of
Artificial active immunity
Describe the general structure of a virus
Contains a protein shell (capsid) with a nucleic acid core (rna or DNA)
Where are naive B cells manufactured?
In the bone marrow
Where are plasma B cells manufactured?
In the lymph nodes
What is an antigen?
A molecule usually a protein that initiates an immune response
Cellular pathogens include?
Bacteria
Non cellular pathogens include?
Prions and viruses
Lymphoid tissue includes the?
Thymus
Plant hormones are also known as
Plant growth regulators
How does relenza work?
inhibits the enzymes that release viruses from host cells.
True or false: the innate immune responses occur after the adaptive immune responses are overcome?
False. Innate occurs first
What is the most common white blood cell circulating in the innate immune system?
Neutrophil
True or False: natural killer cells eliminate pathogens by phagocytosis?
False. Eliminate pathogen infected cells by degranulation
True or false: macrophages of the innate immune system eliminate pathogens by phagocytosis?
True
What type of pathogens can macrophages destroy?
Extracellular pathogens by phagocytosis
What type of pathogens do complement proteins act on?
Extracellular pathogens
What is the main response of the innate immune system?
Acute inflammation
True or false: cytokines released by cells at infection site attract more immune cells to site?
True
True or false: at birth a baby has no adaptive immune defences
False. Some antibodies cross through the placental barrier and enter the blood of the baby
What are the main characteristics of an immunodeficiency disease?
The immune system is partially or totally deficient
The natural flora of the body is a part of which response?
Innate immune response
A distinct difference between bacteria and viruses is what?
Their size
What is an epidemic?
A disease affecting a large number of individuals within a population or region at the same time
What is a pandemic?
The spread of a disease between countries and continents
What is the immune deficiency disease that can result when large numbers of Helper T cells are destroyed?
AIDS (acquired immune deficiency syndrome)
Is the form of immunity initiated by the Helper T cells active or passive?
Active as it involves the production of antibodies and memory cells by the body
Which immune response do dendritic cells belong to?
Non specific response
What are the different types of fossils?
- transitional
- mold
- cust
- direct
- indirect
What is cultural evolution?
The change in human society over time where those changes are socially transmitted not genetically inherited
What is a pathogen?
A causative agent of disease
What is an autoimmune disease?
A disease in which the body identifies some self cells as non self and attacks them
What is active immunity?
When a person produces their own antibodies and memory cells
What are the functions of complement proteins?
- attach to invading micro organisms
- make it easier for phagocytes to ingest
- Lyse plasma membranes of pathogens
- promote inflammation
What are interferons?
Are produced by viral infected cells and warn nearby cells and make them more resistant to infection by stimulating the production of anti viral proteins
What is the function of antibodies?
To bind to specific pathogens/ antigens and cause agglutination so macrophages can then engulf and destroy them
How do hydrophilic hormones stimulate a metabolic process?
- binds to receptor on cell membrane
- secondary messenger is synthesised, carrying signal into cell
- cascade of events occur
How does a plant fight infection?
- grow gall tissue around area containing infective agent to prevent spreading
- produce gum to seal from other areas
- drop infected area inhibit spread
What are the features of inflammation that minimise impact of infection?
- presence of phagocytes
- increased blood flow
- chemicals released by infected cells
- clot or scab forms
What is binary fission?
Cell division occurring in bacteria producing two daughter cells
What are exons?
Are joined to form mRNA and are translated
What are introns?
Sections of pre mRNA removed when splicing occurs
