Module 4 chapter 12 Flashcards
What do pathogens include
- Bacteria
- Virus
- Fungi
- Protoctista
What is a communicable disease caused by
other organism that that infect’s an other
What are infective organisms known as
Pathogens
What is an infectious disease
a disease resulting from infection of a host organism by a pathogen
What are the different types of pathogens
- bacteria
- fungi
- viruses
- parasites
How many people died due to an infectious disease in 2002
14.7 million
What is the most common organism for infection
Bacteria
What cell type are bacteria
Prokaryotes
What are the 2 categories for bacteria
- Basic shape
- cell wall
Give 5 examples of Bacteria shapes
- Rod shapes
- Spherical shapes
- Comma shaped
- Spiralled shaped
- Corkscrew shaped
What are the 2 types of bacteria by cell wall
- Gram positive bacteria
- Gram negative bacteria
What colour do gram positive bacteria appear under a microscope after staining
Blue-purple
What colour do gram negative bacteria appear under a microscope after staining
Red
What is an example of gram positive bacteria
MRSA
What is an example of gram negative bacteria
E.coil
What can affect how bacteria respond to antibiotics
types of membrane
What is a virus
non-living infectious agents
What is a virus made up of
Sort section of RNA surrounded by protein
How do viruses infect cells
inserting it’s own RNA into the DNA of a cell
What happens to the infected cells when a virus inserts its own RNA
Cell will then produce more viruses
What types of organisms do viruses infect
All organisms even bacteria
What are viruses that destroy bacteria called
Bacteriophages
What cell type are Protoctista
Eukaryotic
Are protoctista single or multi cellular organism
Both
How many protista are pathogens
Only a small percentage
Which can protista affect animals or plants
Both
Give an example of protista
malaria
What do protista require to transfer a disease
vector
Which do fungi affect more plants or animals
Plants
Which can fungi affect plants or animals
Both
What cell type are fungi
eukaryotes
Is fungi a multi cellular or single cellular organism
Can be both
Many fungi are Saprohytes what does this mean
they’re of dead decaying matter
Which part of the plant do fungi infect
Leaves
Why do fungi infect the leaves
To prevent photosynthesis
What do the millions of spores that fungi produce do
Rapidly infect other organisms
How do pathogens usually infect other organisms
damage tissues or produce toxins
How do fungi damage tissues
digest and destroy living cells
How do protista damage tissues
- take over the cell
- digest the insides
- reproduce
- burst out
How do viruses damage cells
- takes over cellular metabolism
- inserts RNA into hosts cell’s DNA
- cell reproduces virus
- Burst out of cell destroying it
Which type of toxin do most pathogenic bacteria produce
poison
How does poison damage cells
By breaking down the plasma membrane or inactivating enzymes
What is a vector
Anything that can carry a pathogen without being affected by it
What is an example of a vector
mosquito carrying malaria
What is Tuberculosis (TB) caused by
airborne bacteria Mycobacterium tuberculosis
What does tuberculosis (TB) affect
respiratory system
What fraction of the world is infected with the tuberculosis bacterium
1/3
How can TB be treated
Anti-biotics
What’s emerging from the anti-biotics used to treat TB
antibiotic resistant strains
In healthy people white blood cells engulf TB by what process
phagocytosis
What are white blood cells scientific name
macrophages
What does a tubercle do to TB
Forms around the infected site
How long after the tubercle forms around the site does it take for the infection to heal
3-8 weeks
How long can TB’s bacteria survive inside the macrophages
years
What happens if the patients immune system cannot contain TB
(Active tuberculosis) Bacteria multiplies rapidly destroying lung tissue
What are symptoms of active tuberculosis
- coughing
- shortness of breath
- loss of appetite
- weight loss
- fever
- night sweats
- extreme fatigue
What do fever and night sweats occur due to in TB
Neutrophils and macrophages releasing fever-causing substances
When Neutrophils and macrophages release fever causing substances What response is this apart of
Inflammatory response
What do the chemicals from the inflammatory response affect
hypothalamus and increase our core body temperature
What does HIV stand for
human immunodeficiency virus
What cells does HIV target
T helper cells in the immune system
What type of virus is HIV
retrovirus
What is HIV’s genetic code
RNA
How is HIV shared
- shared needles
- contaminated blood products
- mothers to baby’s during pregnancy
- birth or breast feeding
Which gender is at more risk to HIV
Females
What is malaria caused by
the protoctista Plasmodium
How is malaria spread
the bite of infected Anopheles mosquitoes
What 2 hosts does the Plasmodium parasite have
mosquitoes and people
Where does the plasmodium parasite reporduce
inside the female mosquito
Where does the plasmodium parasite invade
- red blood cells
- liver
- brain
What does malaria do
makes people weak and vulnerable to other infections
What is the key to reduce the number of malaria cases
Control the vector (mosquito)
How can you control mosquitoes
- Insecticides
- remove standing water where they breed
- mosquito nets
What is the Flu
viral infection of the ciliated epithelial cells in the gaseous exchange system
What does the flu do
Kills the epithelial cells leaving airways open to secondary infection
What are the 3 main strands of Flu
A
B
C
Who does flu affect
- mammals
- humans (young, old and chronically ill)
- birds
How are viruses classified
Proteins on their surface
What is Bacterial meningitis
bacterial infection of the meninges of the brain
What can it cause if bacterial meningitis spreads to the rest of the body
cause septicaemia (blood poisoning) and rapid death
What age range does bacterial meningitis affect
15-19
What are the symptoms of bacterial meningitis
blotchy red/purple rash
What is the death rate of bacterial meningitis
10%
Can antibiotics cure bacterial meningitis
Yes if treated early
Can vaccines protect against bacterial meningitis
Only some forms of bacterial meningitis
What is ring worm
fungal disease infecting mammals
What is ring worm caused by in cattle
Trichophyton verrucosum
What does Trichophyton verrucosum cause
Grey-white
crusty
infectious
circular areas of skin
How can you cure ring worm
Anti fungal creams
What is athletes foot
fungal disease
What is athletes foot caused by
Tinia pedia
What is athletes foot a form of
Ring worm
What does athletes foot do
digests the warm, moist skin between toes
What does athletes foot cause
cracking and scaling
How can you treat athletes foot
Antifungal cream
What is ring root (plants)
Ring of decay in the vascular tissue of a potato tuber or tomato, accompanied by leaf wiltering
What organism is ring root
bacterium
What are the 6 contributing factors that increase the spread of disease
- human demographics and behaviour
- Economic development
- microbial development
- breakdown of public health measures
- climate change
- international travel
What are the 7 factors affecting transmission of disease in animals
- overcrowding
- poor nutrition
- compromised immune system
- disposal of waste
- climate change
- culture
- socioeconomic factors
How does climate change affect the transmission of disease
alter the distribution of vector organisms
How does culture affect the transmission of disease
use of traditional medicines
How does socioeconomic factors change affect the transmission of disease
lack of health workers or public warnings
Methods of spreading disease in plants (direct transmission)
contact with leaves
Methods of spreading disease in plants (indirect transmission)
- Soil contamination
- Wind
- Water
- Animals
- Humans
What are the 5 factors affecting transmission of disease in plants
- Susceptibility of disease
- Overcrowding
- resistance
- Climatic conditions
- climate change
What climatic conditions increase of spread of disease (plants)
damp, warm conditions
What factors of resistance affect the transmission of disease (plants)
Poor mineral content of soil reduced resistance
What are the 3 physical barriers to prevent disease
- Waxy cutical
- Bark of tree trunks
- Cellulose cell walls
What do plants do to damage tissue
Section it off and sacrifice it
When do plants release Callose
when a pathogen is detected
What is callose made of
beta glucose monomers
What carbohydrate is callose
Polysaccharide
Where is callose deposited
- between cell walls and membranes next to infected cells
- Plasmodesmata
Why is callose deposited between cells walls
To stop the spread of disease
What substance is added to the Callose barrier to strengthen it
Lignin
What does Callose do to the phloem
Blocks the sieve cells
What do cotton plants produce to deal with pathogens
Phenols (antiseptic)
What are Defensins that the plant produces to deal with pathogens
Plant proteins and disrupt membranes of bacteria and fungi
Name 3 anti fungal compounds
- Gossypol
- Caffeine
- Saponins
What produces Gossypol to deal with fungi
Cotton
Where is Saponins found
Chemical in plant membranes
What does Chitinases do
Break down fungal cell walls
What does Glucanase do
break down glucans found in oomycetes
What is Cyanide do
highly toxic compound in most living organisms
What is the immune system
A group of cells, tissues, organs, and mechanisms that defend against pathogens and other foreign substance
What is an immune response
complex series of specific and non-specific processes
What is involved in the immune response
a range of cells and chemicals
What happens when the body fights of infection and the same infection returns
it will respond more quickly and effectively
What are the 4 physical barriers
- Skin
- Skin flora
- Mucous membranes
- lysozyme
What does the skin produce that inhibits pathogen growth
Sebum and oily substance
What is skin flora
a population of natural health bacteria
How does skin flora protect us against pathogens
the natural health bacteria out compete pathogens for surface space
How do mucous membranes protect us against pathogens
Layer of mucus that traps pathogens
Where can you find mucous membranes
gas exchange surface
What enzyme does the mucus contain
Lysozyme
Where is lysozyme found
- tears
- urine
- stomach acid
What is the first stage of blood clotting and wound repair
Platelets rush to wound and release serotonin and Thromboplastin
What does serotonin do to help heal a wound
causes muscles to contract around the wound reducing the gap
What is the second stage of blood clotting and wound repair
Clot dries out forming a hard scab keeping pathogens from entering
What is the third stage of blood clotting and wound repair
Epidemical (skin) cells grow beneath the scab, collagen fibers reinforce the skin cells
What is inflammation
swelling of skin immediately around the rupture
What is inflammation characterised by
- pain
- heat
- redness
What cells are activated when the skin is ruptured
Mast cells
What do mast cells release when the skin is ruptured
- Histamines
- cytokines
What do Cytokines do
Attract white blood cells to deal with any pathogens
What does histamines do to the red blood cell
cause them to dilate which causes localised heat and redness
What do histamines do to the cell wall
increase the permeability causing tissue fluid to escape which leads to swelling and pain
What is the normal core body temperature
37 degress
What controls your core body temperature
Hypothalamus
What causes the hypothalamus to reset
large presence of white blood cells
What happens when the hypothalamus resets
It increases temperature
How does increasing temperature help fight disease
Pathogens can’t reproduce fast which allows the specific immune system to work faster
How does the non-specific immune response act
quickly and targets a wide range of pathogens and foreign substances
What is the non-specific immune response made up of
- Phagocytosis
- inflammation
- antimicrobial proteins lysozyme
- interferons
What is a lysozyme
Enzyme
What does lysozyme do
disrupts the cell walls of gram positive bacteria
How does lysozyme disrupt the cell walls of gram positive bacteria
by digesting the pertidoglycan
What are interferons
Proteins
What produces interferons
virus infected body cells in response to the virus
Interferons trigger the production of a second protein what does that second protein do
inhibits viral replication by binding to mRNA coded by the virus
How do white blood cells find pathogens
They produce chemicals and other toxins which attract them
How do Phagocytes know if a pathogen is from another organism
They recognise foreign antigens
How does the Phagocyte kill the pathogen
It engulfs it
Where does the pathogen go once it’s been engulfed
puts it into a specialised vacuole called a phagosome
What is a phagolysosome made from
phagosomes combined with lysosomes
What does a lysosome contain
a powerful digestive enzyme
What do enzymes do in the phagolysosome
break down the pathogens
What happens to the broken down pathogen
It’s moved out of the phagocyte by exocytosis
What are Macrophages
specialised phagosomes
Are macrophages faster or slower than normal phagocytosis
Slower they take longer to break pathogens down
Once the pathogen is broken down what happens to the foreign antigens of the pathogen
antigens bind with the antigens of the macrophage to form a histocompatibility- complex (MHC)
What happens to the antigens after a histocompatibility- complex is formed
display the antigens on the macrophages plasma membrane to form a antigen-presenting cell (APC)
What produces opsonins
phagocytes
What do Opsonins do
‘tag’ pathogens making them more visible to other phagocytes
What does the specific or adaptive immune response do
targets specific pathogens
Is the specific or adaptive immune response faster than the non-specific immune response
It’s slower
What are the specifics main types of response to pathogens
- the cellular or cell-mediated response
- the humoral or antibody-mediated response
What does the cellular or cell-mediated response target
pathogens inside the cell
What does the cellular or cell-mediated response involve
Highly specialised cells
What does the humoral or antibody-mediated response target
pathogens in body fluid with antibodies
Where are all cells antigens
On their surface
What are the 2 ways body cells recognise antigens
‘self’
‘foreign’
What are specialised glycoproteins called
immunoglobulins
How will immunoglobulins react to multiple types of antigens
They’re specific and will only bind to 1 type of antigen
How do antibodies bind to antigens
on a lock and key model basis
What causes different variable regions in the antibody
the shape of the antigen
What does the antibody-antigen complex act similar to
the opsonin chemical
How does the antibody-antigen complex act similar to the opsonin chemical
by stimulating the digested by phagocytosis
What happens to the pathogens once they form a antibody-antigen complex
they cannot affect the bodies cells
What are the 2 ways antibodies function in the immune system
Agglutination
Neutralisation
What happens in agglutination
- One antibody binds to 2 pathogens causing them to clump together
- Makes it easier to be engulfed by phagocytosis
What happens in neutralisation
Antibodies act as anti toxins, binding with toxins produced by pathogens making them harmless
What are Lymphocytes
A type of white blood cell
Where are Lymphocytes found
- blood
- lymph nodes
What do lymphocytes recognise
antigen molecules on the surface of pathogens
What does a lymphocytes do once it recognises a pathogen
Co-ordinates the immune response against the pathogen
How can lymphocytes recognise millions of different antigens
A large variation of of lymphocytes produced
What controls the immune system
White blood cells
What are the 2 types of lymphocytes
- B lymphocytes
- T lymphocytes
Where are B lymphocytes formed
bone marrow
Where are T lymphocytes formed
Thymus
What are the 4 types of T lymphocytes
- T helper cells
- T killer cells
- T memory cells
- T regular cells
What do T helper cells do
Produce interleukins (a type of Cytokine)
What does interleukins stimulate
B cell and antibody production which attracts other T cells and antibodies
What do T killer cells do
kill pathogens
How do T cells kill pathogens
produce a chemical called perforin
What does the chemical perforin do
makes holes in pathogens cell plasma membranes
What do T memory cells do
act as immunological memory
How long do T memory cells remain in the blood
Long periods
What do T memory cells do when a second infection occurs
divide rapidly to form many killer T cells
What do T regular cells do
Prevent an autoimmune response
How do T regular cells prevent an autoimmune response
they repress the immune system
When do T regular cells prevent an autoimmune response
When all the pathogens have been destroyed
What are the 3 types of B lymphocytes
- Plasma cells
- B effector cells
- B memory cells
What do plasma cells do
Produce a specific antibodies to an invading antigen
How long do the antibodies live for that are produced by plasma cells
A few days
How many antibodies are produced from the plasma cell when it’s active
up to 2000 a second
What do B effector cells do
divide to form plasma cell clones
What do B memory cells do
remain in the blood for long periods of time
What do B memory cells provide
immunological memory
What happens to B memory cells when an infection occurs
reproduce rapidly and produce the same specific antigen
What is cell-mediated immunity
A response to cells that have been infected by a pathogen mainly viruses
By what process do macrophages engulf and digest pathogens (cell-mediated immunity)
Phagocytosis
What do the macrophages do once they’ve engulfed the pathogens (cell-mediated immunity)
Present the antigens on the surface (become antigen-presenting cells)
What will the specific T helper cell do that fits the antigen on the macrophage (cell-mediated immunity)
It’ll bind and produce Interleukins which stimulate more T cells to be produced
What will be clone T cells become (cell-mediated immunity)
More T helper cells
Why would the clone T cells become more T helper cells (cell-mediated immunity)
To produce more interleukins
What is hormonal immunity
A response to pathogens found in the blood stream
What pathogens are likely to be hormonal
- bacteria
- fungal infection
What is produced when there’s a pathogen in the blood stream (hormonal immunity)
antigens
What’s special about antigens that’re found in the blood stream (hormonal immunity)
They’re soluble in blood, tissue fluid and lymph fluid
What type of cell is most important in (hormonal immunity)
B cells
What do B cells have on their surface (hormonal immunity)
Different antigens
What will the B cells do to the pathogen (hormonal immunity)
Their antigens will bind to the complimentary antigens on the pathogens membrane
What will be B cell do once it engulfs the pathogen (hormonal immunity)
present the antigen on its surface becoming an antigen-presenting cell
What is clonal selection
When the T helper cells bind to the antigens on the presenting B cell
What do the Interleukins do that are produced by the T helper cells (hormonal immunity)
They activate other B cells
How do B cells divide (hormonal immunity)
Mitosis
What is clonal expansion (hormonal immunity)
B cells rapidly divide to produce many different B cells
What are the different types of B cells produced during clonal expansion (hormonal immunity)
plasma and memory cells
What do the cloned plasma cells produce (hormonal immunity)
Specific complimentary antibodies
What do the specific complimentary antibodies do (hormonal immunity)
bind to the pathogen, disabling them or causes agglutination or neutralisation
What do some of the clone B cells for (secondary response)
Memory cells
What does the B memory cell do if the body is infected by the same pathogen again
divides rapidly to produce many plasma cells
Does the correct antigen need to be identified for the secondary response
No making it faster
What happens when the immune system stops recognising ‘self’ antigens
It attacks healthy body tissues
How many different autoimmune diseases are there
80
What is used to prevent the immune system from working
Immune suppressant drugs
What is natural active immunity
A normal immune response to the presents of a pathogen
How does the body respond to pathogens in the natural active immunity
Produces antibodies
When does natural passive immunity take place
During pregnancy
As baby’s don’t have fully developed immune systems where do they get immunity from
Mothers
How does the fetus receive antibodies whilst in the uterus
From the mother across the placenta
What is the placenta
the Bit that attaches the wall of the uterus and the baby’s umbilical cord
When the baby is born how does it still receive antibodies
From the mothers milk
Which milk sample has the most antibodies
The first milk sample
What is the first milk sample called
Colostrum
What makes the mother giving milk to the baby a passive immunity process
The baby isn’t making the antibodies itself
What is artificial passive immunity
Taking antibodies produced by an organism and injecting them into the blood stream of another
How long does artificial passive immunity last
A short period of time
What is an example of a disease where artificial passive immunity is used
- Tetanus
- Rabies
What does Tetanus cause
Muscles to go into a spasm making you unable to breath or swallow
Where is Tetanus found
contaminated soil
animal faeces
What is artificial active immunity
This is a vaccination
What does artificial active immunity get your body to do
Stimulates it to produce antibodies by an immune response
How does artificial active immunity get your body to produce an immune response
By injecting safe antigens into the blood stream
Why don’t vaccines cause illness
- They contain an inactivated form of the pathogen
- Contain an attenuated form of pathogen
- contain cell surface proteins
How is the pathogen inactive from the vaccine
It’s killed by heat treatment
What does attenuated mean
Less virulent
What are the 5 types of antigens
- genetically engineered antigens
- isolated antigens
- toxin molecules that have been altered and detoxified
- attenuated strains of live bacteria or viruses
- killed or inactive bacteria or virus
What’s an example of a bacteria or virus that’s been killed or inactivated
-whooping cough
What’s 3 examples of a attenuated strain of bacteria or virus
- Rubella
- BCG against TB
- polio
What’s 2 examples of a toxin molecule that’s been altered an detoxified
- Diphtheria
- tetanus
What’s an example of when isolated antigens are extracted from the pathogen
Influenza vaccine
What’s an example of a genetically engineered antigen
Hepatitis B
What happens in immunity from vaccination
Antigen is injected into the blood stream but there’s no risk of infection
What happens once the antigen is infected into the blood stream (immunity from vaccination)
Immune response is triggered
What type of cell responds to attach to the antigen (immunity from vaccination)
Specific B cells
What happens to Specific B cells once they bind to the antigen (immunity from vaccination)
B cells cloned to form plasma cells that produce antibodies
What happens to the B cells once the antibodies destroy the antigens (immunity from vaccination)
Become memory cells that remain in the blood
What happens to the B memory cells if the real pathogen gets infected (immunity from vaccination)
They reproduce rapidly
How can new strains of influenza virus constantly emerge
antigens displayed on the virus can change due to mutation
When new strains emerge from the influenza virus what does it cause
Antigenic variation
What does antigenic variation make it hard to do
Immunise a patient against the virus for line with just a single vaccine
How did authors think that the MMR vaccine could cause autism
toxins that are normally destroyed in digestion to move into the blood and if they traveled to the brain might cause autism
What is an epidemic disease
When a communicable disease spread through national level
What is a pandemic disease
When a communicable disease spread throughout international level
What is heard/mass vaccination
Vaccinating a large proportion of the population to reduce spread
What is local vaccination
Vaccinating only the people at most risk (people who travel) or people who are most affected by the disease
What are 2 examples of communicable diseases that cannot be vaccinated against
- Malaria
- HIV/AIDS
What are antibiotics
A group of drugs used to treat bacterial infections
What are antibiotics effective against
Prokaryotic cells
What are the 2 types of antibiotics
- Bactericidal
- bacteriostatic
What do bactericidal’s do
Kill bacterial cells
What do bacteriostatic’s do
Slow the growth/reproduction of bacteria
What happens when antibiotics prevent the formation of bacterial cell walls
Results in osmotic lysis
What happens when bacteria becomes resistant to antibiotics
a super-bug is made and normal antibiotics won’t work on it
What are the 3 methods of prevention and control of antibiotic resistant bacteria
- Only be prescribed when needed
- need to finish the course
- infection control in hospitals
