4.1.1 Flashcards
What organism causes TB?
Mycobacterium tuberculosis
What is the transmission of TB?
droplets of water in air
released through sneezing and coughing
inhaled by uninfected individual
What parts of the world are most likely to get TB?
overcrowded
poorly-ventilated
have poor diet/malnutrition
homelessness
eating meat / drinking milk from infected cattle
What organism causes bacterial meningitis?
bacteria
What is the transmission of bacterial meningitis?
direct transmission
touch, kissing
What organism causes ringrot?
bacterium
How is ringrot transmitted?
through vectors like insects
indirect transmission
How do insects spread ringrot?
leave spores in the soil
What organism causes HIV / AIDS?
Virus
What does HIV stand for?
Human Immunodeficiency virus
What does AIDS stand for?
Autoimmune deficiency
What does HIV/AIDS do to the immune system?
destroys T helper cells
What happens because T helper cells are killed by HIV/AIDS
Resistance to infection is lowered as T helper cells fight infection
What organism causes influennza?
virus
How is influenza transmitted?
caused by spread of virus
through air
coughs and sneezes
touching contaminated surfaces
DIRECT and INDIRECT
What organism causes Tobacco mosaic virus?
Virus
How is TMV transmitted?
leaves of different plants rubbing together
leaving spores in soil
Direct transmission
What organism causes Malaria?
vector - female mosquito
How is malaria transmitted?
mosquito feeds on human by biting them
parasite passes from saliva of female mosquito into blood stream
What happens when the plasmodium parasite enters the blood stream?
infects hepatocytes and erythrocytes causes disruption to blood flow to vital organs
Why do primary defences not prevent the entry of plasmodium?
vector breaks the skin so that skin no longer acts as a barrier
plasmodium feeds on blood
What organism causes potato/tomato late blight?
protoctista
How is potato/tomato late blight transmitted?
transferred through water eg rain
indirect contact
What is ringworm in cattle caused by?
fungi
How is ring worm spread through cattle?
direct contact through cattle
What causes athletes foot?
fungi
How is athletes foot transmitted?
direct contact with infection by skin particles left on towels, shoes, floors
What is black sigatoka is caused by?
fungus
How is black sigatoka transmitted?
spores carried by wind and water
Why may people object to using insecticides to get rid of malaria?
destruction of a species is morally wrong
What indicates the malarial parasite is not a prokaryote?
has a nucleus
has mitochondria / golgi
linear chromosomes
DNA associated with histones
80S ribosomes
no cell wall
What is health?
physical and mental social well-being
good nutrition
suitably housed
free from disease/illness
What is disease?
impairment of an organisms normal functioning
malfunctioning of body or mind
symptoms may be physical, mental or social
What is a parasite?
an organism that lives in or on and harms the host
How does a paraasite harm the host?
take their nutrition
feeds on host
Example of parasite?
Plasmodium
What is a pathogen?
Micro-organisms that cause disease
How do bacteria cause disease?
damaging cell
releasing toxins
What speed do bacteria reproduce?
fast
What is an example of bacteria?
cholera
Where does fungi live?
in the skin
What does fungi do to skin?
Sends out reproductive hyphae
they grow out to the surface of the skin and release spores
What do viruses do to cells?
invade cells
take over genetic machinery and other organelles of the cell
What do protoctista do?
enters host cells and feeds on contents as it grows
How does the plasmodium feed on the contents of RBC
IMMATURE FORM THAT FEEDS ON CONTENTS
What are some examples of indirect contact?
Vector born
Vehicle born - air, dust, blood, water, food
What are some examples of direct contact?
mother to baby through placenta
touching , kissing
What polysaccharide is released when plants are attacked as a physical defence?
Callose
How fast is callose released?
within minutes
Where is callose deposited?
into cell wals
What reinforces callose when it is deposited into cell wall?
lignin
What is beneficial about callose being reinforced with lignin?
provides a thicker barrier for pathogen to penetrate through
What does callose block in the phloem?
sieve tube end plates
What does callose do to infected areas?
seals it off
What does callose block between infected cells?
plasmodesmata
What is beneficial about having Tannins as a chemical defence?
bitter taste
What is beneficial about antibacterial compounds being a chemical defence of a plant?
disrupts cell wall/ membranes of bacterua
What is an example of an anti-fungal compound?
chitinases
What is beneficial about chitinases being a chemical defence?
enzymes released to break down chitin in cell wall
What is beneficial about anti-oomycetes being released from plants?
breaks down cell walls on fungi
What does the skin act as?
barrier
What do skin flora do?
outcompete pathogens
What happens to pathogens as a result of skin flora?
no longer alive
What does the thi layer of dead cells on skin act as?
barrier to pathogens
What is beneficil about sebum on skin?
prevents pathogen growth
What do goblet cells line?
Airways
lungs
digestive systems
What do goblet cells do?
trap microorganisms
What happens to microorganisms trapped by goblet cells?
destroyed by phagocytes and lysozyme
What is a primary defence in the stomach?
HCL
What is a primary defence in our ears?
wax
What is a primary defence in our eyes?
lysozyme
What primary defences are in the female reproductive system ?
acidic conditions
What are histamines released by?
mast cellsW
What do histamines do?
detect infection
What does histamine do to arterioles?
dilate
What does arteriole dilation cause?
localised heat and redness
What does the inc in temp do to histamines?
prevents pathogens from reproducing
What will histamines do to the capillaries?
make them more leaky
What does making capillaries more leaky cause?
more tissue fluid to form
(swelling)
What 2 things does swelling cause to happen?
more WBC to be brung to that area
morefluid enters lymphatic system
What do cytokines do?
attract more phagocytes to infected area
Why do cytokines attract more phagocytes to the infected area?
so cytokines can dispose of them by phagocytosis
What is excess tissue fluid drained into?
lymphatic system
What will pathogens enter before being transported to lymph nodes?
lymph
What will pathogens be transpirted to after entering the lymph?
lymph nodes
What happens when lymph nodes swell?
produces phagocytes and lymphocytes
What are expulsive reflexes?
coughing
sneezing
What is a non-specific defence mechanism?
Response is immediate and the same for all pathogens
What is a specific defence-mechanism?
Response is slower and is specific to each pathogen
What are 2 non-specific defence mechanisms?
Physical barrier
Phagocytoss
What are 2 specific defence mechanisms?
Cell-mediated response
Hummoral response
What is engulfed in phagocytosis?
pathogen
What is formed when the pathogen is engulfed?
Phagosome
What moves towards the phagosome?
lysosomes
What do hydrolytic enzymes do to the pathogen?
break it down
What happens to harmless products in phagocytosis?
absorbed into cytoplasm
What is formed at the end of phagocytosis?
Antigen presenting cell
Outline phagocytosis?
Pathogen enguled
Phagosome formed
Lysosomes fuse with phagososme
Lysins break down pathogen by hydrolysis
Harmless products absorbed into cytoplasm
APC formed
What are cytokines released from?
T helper cells
What deos cytokines trigger?
clonal expansion of B cells
What do opsonins do?
process by which an antibody binds to another substance
What shape nucleus do neutrophils have?
lobed
What nucleus do lymphovytes have?
spherical
What structure do erythrocytes have?
biconcave
What structure do erythrocytes have?
biconcave
Whst shaped nucleus do phagocytes have?
lobed
Explain how phagocytes, such as those shown in Fig. 3.1, are able to pass from the
blood into the tissue fluid.
lobed / narrow , nucleus ;
(cells) can change shape ;
can squeeze / move / fit / AW , between cells
/ through pores , in (walls of) capillaries ;
histamine makes , capillary walls /
endothelium , leaky ;
What structure do monocytes have?
unilobular nuelci
What is an immune response?
response to an antigen
Involves lymphocytes / production of antibodies
What is special about the receptors on the T helper cell?
they are specific and complimentary to the APC’s antigens
What is clonal selection?
T helper cell identifies a foreign antigen from a foreign pathogen in the body
What happens after clonal selection in cell-mediated response?
clonal expansion
What cell undergoes clonal expansion in cell-mediated response??
T helper cell
What process happens during clonal expansion in cell-mediated response? ?q
mitosis
What 4 cells does clonal expansion produce in cell-mediated response??
T helper cells
T killer cells
T memory cells
T regulatory cells
What is the cell-mediated response?
T helper cell’s receptors identify the antigens on the APC as foreign.
T helper cell undergoes clonal expansion by mitosis
4 cell types produced
T helper
T killer
T memory
T regulatory
What type of cell is used in cell mediated response?
T cells
What does the T helper cell do in the hummoral response?
undergoes clonal expansion after receptors identify foreign antigen on APC
What chemicals does the T helper cells release in the hummoral response?
interleukins
cytokines
What cells undergo clonal expansion in hummoral response?
B cells
What is clonal expansion?
cells differentiate into other cell types
What cells are produced in clonal expansion in the hummoral response?
B memory cells
Plasma cells
Why are plasma cells useful?
make antibodies
Why are B memory cells useful?
Allows immune system tor rememeber previous antigens so antibodies can be produced quiclker
Why are T helper cells useful?
identify antigens
Why are T killer cells sueful?
kill our own body cells that have been infected
Why are T memory cells useful?
allows body to recognise the same antigen so antibodies can be quixkl produced
Why are T regulatory cells useful?
suppresses immune system
maintain homeostasis
prevents autoimmune disease
Which response primary or secondary will generate the most antibodies?
secondary
Why is the secondayr immune response shorter and quicker than primary?
no memory cells in primary
(T and B)
clonal selection and expansion occur quicker in secondary
more plasma cells
so more antibodies being made
What is herd vaccination?
high % of people have immunity
What is ring vaccination?
most vulnerable are protected
What molecule is an antibody?
protein
How many polypeptide chains in an antibody?
4
How many light and heavy polypeptide chains?
2 light and 2 heavy
How does the structure of an antibody relate to it’s function?
2 light chains and 2 heavy chains / 4 polypeptide
chains ;
variable region allows , binding / attachment , to
antigen ;
two variable regions allow binding of more than
one (of the same) antigen ;
variable region on different antibodies allows specificity
to different antigens ;
constant region allows , recognition by / attachment to /
binding to , (named) phagocytes ;
hinge (region) allows flexibility ;
disulfide , bonds / bridges , hold , polypeptides / light
and heavy chains , together ;
What is special about the variable region on an antibody?
complimenary and specific to an antigen
What is the role of the hinge region?
allows antibody to bind to more than 1 antigen or pathogen
What does the constant region allow?
allows antibodies to find phagocytes
Whateffect does opsonins have on phagocytosis?
inc chance
Why do opsonins inc chance of phagocytosis?
antibody can bind o both pathogen and phagocyte
What is agglutination?
pathogens clump together
Why does agglutination happen?
makes pathogens too large to enter the host cell and increases the likelihood of phagocytosis
What is neutralisation?
antibodies cover binding sites on the pathogen or bind to toxins
Why do antibodies cover binding sites on the pathogen or bind to toxins?
prevent binding or entry into the host cell
How is artificial immunity achieved?
MAN-MADE
USUALLY THROUGH INJECTIONS
wHAT IS NATURAL IMMUNITY?
NATURAL CAUSE CATCHING A DISEASE
What is pasive immuniuty ?
does not trigger an immune response
What is active immunity?
does trigger an immune response
What is an example of natural passive immunity?
antibodies provided by the placenta or by breast milk
allows the baby to be immune to diseases that the mother is immune to
What is an example of artificial passive immunity?
an injecction of antibodies made by another individual
What is an example of natural active immunity?
being infected by or sufferig suffering from a disease
causing body to produce antibodies and make mmroy cells
What is artificial active immunity?
weakened or dead pathogen introduced by vaccination
What is an autoimmune disease?
abnormal immune response
against tissues normally in the body
How does the autoimmune disease treat self-cells?
unable to recognise them as self
treats them as foreign
What is lupus?
immune system attacks healthy cells
effects connective tissues/joints/skins
What does rheumatoid athritis attack?
joints
Where are the joins that athritis attacks?
hands
wrists
feet
ankles
What are the symptoms of lupus and athritis?
pain inflammation fatigue
How to treat lupus and athritis?
pain killers
anti-inflammatories
steroids
immuno-supressants
What is type 1 diabetes?
attack insulin secreting beta cells of the pancreas
How can type 1 diabetes be treated?
insulin injections
pancreatic transplant
immunosupressants
What vaccinations prevent?
epidemics
Why is beneficial to vaccinate the population?
so that there is little impact on the economy (people can work)
cheaper to prevent a disease than treat an ill person
Why are new vaccines generated each year?
different strains of the virus
different strains have different antigens
antibody produced needs to match the new antigen
Why is it important to maintain biodiversity?
inc gene pool
pop more likely to withstand a change
source of potential medi
How can pharmacogenetics be used to treat ill people?
predicts an organisms response to medical drugs by studying their genome
What is MRSA?
a type of bacteria that is resistant to severly widely used antibiotics
What is harder to treat MRSA infection or bacterial infections?
MRSA
How have resistant strands of bacteria evolved?
genetic variation within population
What happens when a random mutation arises?
gives rise to antibiotic resistance allele
What is the selection pressure of the bacteria?
antibiotics
What happens to the allele coding for antibiotic resistance?
allele passed onto offspring
What happens to allele frequency over many generations?
inc
How does bcteria become resistant?
variety ofbacteria
bathed in antibiotics
most normal bacteria die
resitant bacteria multiply and become more common
entire infection evolves into resistant strain
What type of organism can have an immune response?
multicellullar
