IMMUNE SYSTEM Flashcards
what are the 2 characteristics of Bacteria
Unicellular prokaryote
divided by binary fission
what are the 2 characteristics of a virus
non-living acellular
contains genetic material
what are the 3 steps of virus reproduction
- infects and injects DNA/RNA
- infected cells is induced to translate/transcribe the genes of DNA/RNA
- virus particles then able to leave host cell to infect others
what are the 6 modes of pathogen transmission
- Contact - directed and undirected
- Transmission through droplets
- Bodily fluid transfer
- Airborne transmission
- Ingestion transmission
- Vector transmission
what are 2 characteristics of Non-specific defence
all pathogen protection
first/second line of defence
what are 3 characteristics of specific defence
- particular pathogen targeted
- 3rd line of defence
- antibodies against specific virus
what are the 5 modes of external defence
- skin
- mucous membranes
- acids
- mouth
- bodily openings
why is skin effective as a component of external defence (4)
stratified epithelial structure
bacteria occupies surface (preventing growth)
sebum oily secretion preventing cracking
sweat - salty preventing growth
why are mucous membranes effective in external defence
- membranes secrete mucous (trapping microorganisms
- contains lysosome
- cilia traps foreign particles
what are acids an effective component of external defence
acids reduce growth of microorganisms (strongly acidic killing bacteria)
why is the mouth an effective component of external defence
saliva contains lysosome
why are bodily openings an effective component of external defence
nose - hair/mucus
eyes - mucus membrane protection
ears - ceraumen
what are the 4 protective reflexes in external defence
- coughing
- sneezing
- vomiting
- Diarrhoea
what is apoptosis
programmed cell death - infected cells, cancerous cells
what cells do specific defence include
T cells
B cells
what cells does non-specific defence include
macrophages
neutrophils
define the humoral response/antibody-mediated
antibody-mediated
- production of antibodies to attack invading pathogens
define the cell-mediated
formation of special cells (killer cells) to invade foreign agents
what cells to B cells produce and where do they mature ?
Produce Antibodies
Mature in bone marrow
what do T cells provide and where do they mature ?
Provide cell-mediated immunity
mature in thymus
what cells are involved in antibody-mediated immunity ?
plasma cells
memory B cells
what do plasma cells do
produce antibodies that attack the antigen
what do memory T/B cells do
spread around the body and are present for a faster response next time exposed
what cells are involved in cell-mediated immunity?
Killer T cells
Helper T cells
suppressor T cells
memory T cells
what do killer T-cells do
kill cells infected with the vial pathogen
what do helper T-cells do
intensify immune response secreting cytokines which activate more B/T cells
what do suppressor T-cells do
control and regulate immune response and help end immune response
(opposes helper T cells)
define inflammation
the response to tissue damage involving swelling, heat, pain and redness of infected area
4 functions of inflammation
- mobilise defensive cells
- limits spread of pathogens
- kills pathogens - removing damaged cells/cell debris
- initiates repair of damaged cells
4 signs of inflammation
- redness
- swelling
- heat
- pain
define 4 functions of fever
- inhibits growth of bacteria / viruses
- speeds up rate of chemical reactions in body
- increases heart rate and blood flow (WBC reach site quicker)
- increases effect of interferon (interfering with viral reproduction)
how is fever produced
during inflammatory response, some white blood cells release PYROGENS which act on HYPOTHALAMUS to reset body’s thermostat to a higher temp
when body’s thermostat is raised what does a person do?
persons body temp - LOWER THAN NORMAL ( new thermostat temp)
feels cold - shiver/vasoconstrict
when thermostat is raised, what type of activities does the body do
heat conserving and producing activities are done to drive temp up rapidly
= breaks fever
when fever breaks what does a person do?
FEVER BREAKS
persons body temp - HIGHER THAN USUAL ( @ fever )
feels cold - sweat / vasodilate
define the function of the lymphatic system
collects fluid that escapes from blood capillaries and returns it into the circulatory system
BODY’s INTERNAL DEFENCE
what is a lymphocyte
white blood cell that is responsible for immune response
define an Antigen
any substance capable of causing the formation of antibodies when introduced into the tissues
capable of causing specific immune response
define self antigen
molecules that don’t trigger an immune tesponse
define non-self antigen
foreign molecules that trigger an immune response
define an Antibody
a substance produced in response to a specific antigens
combines with antigen to neutralise and destroy it
ANTIGEN-ANTIBODY COMPLEX
define Antibiotics
drugs used to fight BACTERIAL infections
what are broad-spectrum antibiotics
effective at killing wide range of bacteria
what are narrow spectrum antibiotics
only effective at killing specific disease causing microorganisms
define Bacteriocidal
KILLS BACTERIA by changing structure of cell membrane, or by disrupting the action of enzymes
define Bacteriostatic
STOPS BACTERIA FROM REPRODUCING through disrupting protein-synthesis or inhibiting DNA replication
what are antivirals
drugs used to specifically treat viral infections
define immunisation
programming the immune system
define a vaccination
artificial introduction of antigens of pathogenic organisms so that the ability to produce antibodies is acquired without person having to suffer disease
4 types of artificial immunisation (vaccine)
- living attenuated microorganisms
- dead microorganisms
- toxoids
- sub-unit
2 types of immunity
natural immunity
artificial immunity
define immunity
resistance to infection by invading microorganisms
what is natural immunity
occurs without human intervention
what is artificial immunity
results from giving an antibody/antigen
2 characteristics of ACTIVE immunity
produced own antibodies (given antigens to produce antibodies)
exposed to antigens (self/nonself)
4 characteristics of PASSIVE immunity
given antibodies
no exposure to antigens
no immune response
no memory cells
define Living attenuated microorganisms
Attenuated - reduced ability to cause disease symptoms
Pro’s for Living attenuated microorganisms
stimulates excellent immune response / can replicate
Cons for Living attenuated microorganisms
microorganisms can mutate, living bacteria can be contaminated by virus
define what is in the Dead microorganism vaccines
Dead pathogen microorganism is injected into to patient
Pro of dead microorganism vaccines
no live components so no risk of developing disease
Cons of dead microorganism vaccines
not living - may not induce strong immune response
What does a Sub-unit vaccine include
a fragment/particular protein of a particular pathogen used and injected
Subunit vaccine Pro
components aren’t living
response can be safer/more stable
Subunit vaccine cons
effort/cost requires to research the particular fragment that will produce the effective response
What is a Toxoid vaccine
Bacteria produce their effects on human by releasing toxins - teach body how to kill toxin, not bacteria
toxin from a pathogenic organism that is altered so that it is no longer toxic
Toxoid vaccine Pro
cannot cause disease
vaccine antigens not actively multiplying
Toxoid vaccine cons
may require several doses / booster shots
define Herd Immunity
resistance to the spread of an infectious disease within a population that is based on pre-existing immunity due to an increased proportion of individuals as a result of a previous infection/vaccination
define a booster shot
additional dose of the vaccine needed to periodically ‘boost’ immune system
2 Social concerns of vaccines
- internet/media - misinformation about risks/benefits on immunisation
- recent growth in popularity of alternative medicine gives the beliefs that vaccines are greater risk than benefit
2 cultural concerns of vaccines
religious beliefs
traditional medicine is considered superior to conventional medicine
2 economic concerns of vaccines
developing countries (average income - lower parent education)
costs associated with vaccines my be too expensive
