disease infection and immunity Flashcards
pathogen that causes cholera
vibrio cholerae
pathogen that causes malaria
plasmodium vivax/ovale/malariae
pathogen that causes tuberculosis
mycobacterium tuberculosis
pathogen that causes HIV/aids
human immunodeficiency virus
how is it transmitted and how to prevent cholera
water and food sources
improve sanitation and hygiene
how is it transmitted and how to prevent malaria
infected female mosquitos
reduce number of mosquitos and prevent biting mosquito nets, Destroy habitat
how is it transmitted and how to prevent tuberculosis
airborne water droplets from coughing and sneezing
use tb vaccine, cover mouth and nose when coughing and sneezing, dont come in contact with others
how is it transmitted HIV
sexually transmitted and in bodily fluids like blood
take him medicine, use clean needles, screen blood donations to make sure they are not HIV positive
why do antibiotics not affect viruses
virus dont have a cell wall which can be attacked by antobiotics
virus reproduce in host cell
penicillin acting on bacteria
autolysins hydrolyse peptide bonds which allow bacterial growth. penicillin irreversibly binds to the enzyme transpeptidase that form peptide bonds. As the cell grows autolysins continue to break down the cell wall and it becomes so weak the cells bursts due to somatic pressure
neutrophil mode of action
chemotaxis
antibodies stimulate neutrophils to attack pathogens
endocytosis
secret digestive enzyme from lysosome into vacuole
neutrophils die
self-antigen vs non-self antigen
non-self is any substance ore cell recognised by the immune system as foreign, stimulates an immune response
self- any substance produced by the body and does not stimulate an immune response
primary immune response
when the body encounters a pathogen for the first time the immune system initiates antibody production which destroys the pathogen
role of memory cells in secondary immune system
t and b memory cells are also produced so if body were to encounter same pathogen again it would immediately destroy it
natural passive immunity
a mother passes on antibodies to baby through placenta
active natural immunity
individual develops the disease and the immune system makes antibodies and memory cells
lobed nucleus, granular cytoplasm, most common phagocyte(60%)
neutrophil
why does neutrophil need lots of lysosomes
carrying out phagocytosis needs to break down pathogens
bean shaped nucleus and non-granular cytoplasm
macrophage
macrophage is a matured
monocyte
non granular cytoplasm and large round nucleus
lymphocyte
what’s bigger red or white blood cell
white blood cells are bigger
phagocytes are produced in the
bone marrow
neutrophils patrol tissues
constantly travel in blood
are neutrophils long or short lived
short, they die after phagocytosis and from pus
chemotaxis
histamine released by cells under attack and the presence of antibodies attract neutrophils to site where pathogens are located
macrophages dont remain in blood they travel to
lungs, liver,spleen,kidney,lymph nodes
what’s bigger lymphocyte or phagocyte
phagocyte
lymphocytes are made in the
bone marrow
T cells mature in the
thymus
B cells mature in the
bone marrow
b and T cell receptor differences
B cell has glycoprotein antibody receptor
antibody structure
2 light 2 heavy chains
disulphide bonds linking chains
variable region(antigen binding site)
hinge region
maturing of b lymphocytes
genes that code for antibody change so it codes for one specific antibody
specialised B cell divides via mitosis to produced clones with the same type of antibody
antibodies can bond to specific antigens
b lymphocytes during immune response
clonal selection
clonal expansion
some daughter cells become plasma cells and other cells become memory cells
plasma cells
produce antibodies and secrete them into blood lymph and lining of lungs which bind to antigens
clonal expansion
rapid mitosis of specific antibody producing cells
clonal selection
identification of an antibody producing cell with complementary receptors to the shape of a specific antigen
memory cells
memory cells produced in primary response divide by mitosis and develop into plasma cells and more memory cells. specific anitobides can be produced quickly and in large quantities before symptoms of the pathogen develop
memory cells provide
immunological memory
plasma cell adaptations
extensive network of rer for protein synthesis and many mitochondria to provide app for protein synthesis and movement of exocytosis
functions of T cells during immune response
antigen presentation attracts T cells and stimulates them to divide by mitosis
t helper cells are activated by
antigen presenting macrophage or infected body cell
what do helper t cells do
release chemicals called cytokines stimulating B cells to divide by mitosis and form plasma and memory cells and cytokines that stimulate killer T cells to divide by mitosis and differentiate by producing vacuoles full of toxins
what to killer T cells do
their receptors bind to the non self antigens on the cell surface membrane of the infected cells and the killer T cells attach themselves tot eh surface on infected cells. they punch hole in the cell surface membrane of the infected body cells
they infect the body cell and the pathogen inside
what are killer T cells activated by
antigen presenting macrophages or infected body cells or helper T cells
active artificial immunity
vaccine injects inactive pathogen to activate an immune response and antibody production
passive artificial immunity
injection of antibodies from another animal
non specific responses of body
phagocytosis
inflammation
interferon
t helper cells
stimulate B cells and t killer cells to divide
t killer cells
destroy pathogen infected cells by punching hole in cell membrane
long term use of memory cells
replicate themselves when exposed to invading pathogen and remain in the lymph nodes searching for the same antigen resulting in a much faster immune response
how do antibodies kill pathogen
combine w/virus to prevent them entering cell
multiple antigen binding sites causing agglutination reducing spread
cholera control
Ready access to treatments such as oral rehydration therapy; a solution containing glucose, salts and water
Monitoring programmes by the World Health Organisation (WHO)
Using antibiotics in severe cases
is there a vaccine for cholera
yes
is cholera a bacteria or virus
bacteria
preventing maleria
Reducing the number of Anopheles mosquitoes in an area
Spraying living areas with insecticides
Spreading oil over the surface of water bodies in which mosquitoes breed
Draining marshes and other unnecessary bodies of water
Ensuring ponds and irrigation or drainage ditches are stocked with fish that feed on mosquito larvae
Unfortunately, mosquitoes lay eggs in even very small puddles and pools of water and therefore it is practically impossible to control all breeding sites using the methods listed above
Reducing the chance of being bitten by these mosquitoes
People in malarial zones should sleep under bed nets, which can also be soaked periodically in insecticide to increase effectiveness,
People should avoid exposing their skin at dusk when mosquitoes are most active
Using drugs to prevent Plasmodium infecting humans
Drugs, such as chloroquine and mefloquine, are taken before, during and after a visit to a location where malaria is prevalent.
The use of these drugs has resulted in drug-resistant strains of Plasmodium
The drugs are expensive and can have disagreeable side-effects
prevention of tb
Prevention of TB occurs through the use of the BCG vaccine
The vaccine protects up to 70-80% of those who receive it, although its effectiveness decreases with age
The form of TB that can be transmitted between cattle and humans (caused by Mycobacterium bovis) can be prevented by:
Routinely testing cattle for TB and destroying those that test positive
Pasteurising milk; this kills any TB-causing bacteria present in the milk
Ensuring that meat is cooked properly
