6B Flashcards
What is non specific response
Same regardless of the pathogen that invades the body
What’s is specific
Specific to particular pathogen
Able to recognise specific pathogen due to the presence of antigens on their cell surface
What steps of inflammation
Non specific
Mast cells respond to tissue damage by secreting histamine
This causes blood vessel to dilate leading to redness reducing the reproduction rate of pathogen
Histamine makes the cell forming the walls of the capillaries separate slightly thus making the Capillary walls become more permeable allowing fluids to enter the tissue and create swelling
—> releasing plasma contains leukocytes out forcing antibodies out of the capillaries
Disabling pathogens
The antibodies disable the pathogens and macrophages and neutrophils destroy them by phagocytosis
Phagocytes leave the blood and enter the tissue to engulf foreign particles
What do interons do
They inhibit the production of viral proteins preventing the virus from replication
They activate white blood cells involved with the specific immune response to destroy infected cells
They in case the non specific immune respe
How does fevers
Why does the Hypothalamus reset the body temperature higher
Non specific
Many pathogens reproduce quickly at 37c can’t below so higher temperatures will reduce their ability to effectively reproduce
Specific immune response function better at higher temperature making combat against the infection more successful
How is fever beneficial
Patient will start to sweat to cool the body down releasing fluid and electrolyte
If not replaced this could lead to severe dehydration it can cause enzyme to denature resulting permanent tissue damage
Phagocytosis
1)Chemicals released by pathogens as well as chemicals released by the body cells under attack
2)They move towards pathogen and recognise the antigens on the surface of the pathogen as Beng non-self
3) the cell surface membrane of phagocytes extend out and around the pathogen, engulfing it and trapping the pathogen within a phagocytes vacuole
—> endocytosis
4) enzyme are released into the phagocytic vacuole when lysosome fuse with it
5) these digestive enzyme, which includes lysosomes digest the pathogens
6)after digesting the pathogen , the phagocytes will present the antigens of the pathogen on its cell surface membrane
Where is T cell produced from
Produced in the bone marrow and activated in the thymus gland
What’s is T killer cell used for
Produce chemicals to destroy infected cells
What is helper T cell usedfor
Activate plasma cell to produce “ antigens - specific” antibodies and secrete opsonin to label pathogens for phagocytosis
T memory cell
Where is B cell produced and what it produces
Produced in the bone marrow
These cells have globular receptor proteins sued in producing immunoglobulin (antibodies
What does B effector cells do
Divide to form plasma clones
What does plasma cell
Produce antigen specific antibodies
B memory cell
Provide immunological memory (secondary response)
What does humoral response
Production of antibodies
Humoral response
T helper activation stage
Effector stage
T helper activation stage
1)Bacterium with antigens on surface
2) bacterium engulfed by a macrophages
3)macrophages present the antigens from the bacterium on major his to compatibility complexes (MHCs) it becomes an antigen presenting cell (APC)
4) a macrophages APC binds to T helper cell. Once the T cell is activated, it divides to form T memory cells and active T helper cell
Effector stage
1)Bacterium with antigens on surface
2) antigens binds to B a cell with complementary receptor. The B cell engulfs the bacterium by endocytosis and enzyme break it down to leave antigen fragments
Effector step 3
B cells becomes an APC
Effector step 4
An activated T helper cell with a complementary receptor binds to the APC. It produces cytokines that stimuli the B cell
Effector stage 5
The B cell divides to give B memory and B effector cells
Effector stage 6
B effector cells differentiate into plasma cell
Plasma cells secrete antibodies these bind to the antigens on other similar pathogens identifying them so they are easier to destroy
What is agglutination
Binding to antigens on pathogens to make them stick together
What is opsonisation
Antibodies act as an opsonin making pathogens more easily recognised by phagocytosis
What neutralisation
Binding to bacterial toxins to reduce their effect
Cell mediated response step 1
A bacterium infects a host cell
Cell mediated response step 2
Host cell present the antigens on MHCs and become an APC
Cell mediated response step 3
T killer cell with complementary receptor binds to the APC
Cytokines from activated T helper cells
Cell mediated response step 5
Stimulated by cytokines from the T helper cell the T killer cell divides and differentiate to form two clones one of the active T killer cells and one of T killer memory cells
Cell mediated response step 6
The active T killer cells bind to infected cells presenting antigens on MHCs
Cell mediated response step 7
The T killer cells releases chemicals causes lysis in the infected cell as pores form in the membrane the infected cell dies
What happens in primary response
Number of T and B cells with correct membrane receptors are Low
To be activated and divide and differential into different cell types
It can take several days before plasma cells develops and are able to start producing antibodies against antigen
—> infected person will experience symptoms
Both B and T cells produce memory cells during the primary respe which will remain in the blood after infection is over
Secondary response
Faster and stronger than the primary response
Memory cells are present in larger quantities tha the mature lymphocytes at the start of the primary response so the correct memory cell are able to detect an antigen activate divide by mitosis and differentiate much more quickly
Antibodies are produced more quickly and are in larger quantities
Natural active immunity
When your body comes into contact with a foreign antigen, causing the immune system to be activated to produce antibodies against the pathogen to destroy it
What is natural passive immunity
Temporary immunity given from the mother to the fetus , through the transfer of pro formed antibodies through placenta or the mother milk and this last until the fetus immune system become active
Artificial passive immunity
Where antibodies from one individual are extracted and injected in another , which prevents development of the disease , but not give long term immunity
Artificial active immunity
Small amount of a safe form the pathogen are used to grant immunity
- injection of detoxified form of toxin
-inactivated viruses or dead bacteria
-attenuated pathogens
-using fragments of outer coat of viruses
Eradication of disease
Disease not found in either people animals or anywhere in the environment
Elimination of disease
Disease disappears but remains in animals, the environment or mild infection so immunisation must continue regardless of the number of cases
Here immunity
Large portion of the population is vaccinated against a disease, so that it becomes very difficult for the disease to keep affecting who can be vaccinated is vaccinated, so that those who cannot be vaccinated don’t catch the disease. It is important to provide herd immunity when there is a serious outbreak of a disease
Drugs against micro-organism
Antibiotics destroy microorganisms or prevent them from reproducing, and along with immunisation this has cured many diseases.
Antibiotics work based on selective toxicity, by interfering with the chemistry or metabolism of the bacteria without affecting the human host
What is bacteriostatic
Inhibit the growth of bacteria
Define Bactericidal
Kills bacteria
What are the 2 actions of bacteriostatic
Interrupting metabolic pathways to block nucleic acid or viral nutrients synthesis
Protein synthesis inhibition or prevention of transcription and translation of microbial genes
What are Bactericidal 3 actions
1) prevent formation of cross linking cell walls to kill bacteria by lysis
2) damage the cell membrane so water moves in to metabolite or move out killing the bacteria
3) stop bacterial DNA winding into rings so that it can no longer fit inside the cell
Factors that affect the antibiotics
- concentration of drug around infected area
-local pH
-whether the pathogen or host cell destroy the antibiotics
-susceptibility of pathogens to the antibiotics used
Dose of drug
If the standard dose of drug destroy the pathogens and cures the disease, the pathogen is said to be sensitive to the antibiotic.
Drug resistant
1) a group of bacteria include genetically resistant ones, are exposed to an antibiotic
2) most of the sensitive bacteria die
3) the genetically resistant bacteria starts multiplying
4) eventually the resistant strain replaces the strain affected by the antibiotics
How to reduce selection pressure
- use antibiotics only when strictly necessary
-making sure people complete their antibiotics course
-using as few different antibiotics as possible and introduce new antibiotics when possible
MRSA
S.aureus can be the skin or inside nasal passage without affecting, once inside the body it can have negative effect
Treated with methicillin but has now develop3d a resistance
High dosage with narrow of drugs
Clastrrdium difficile
This is an anaerobic bacteria which can be present in the body and not cause harm as they’re their number are limited
Controlling the use of antibiotics
Antibiotics should be used carefully only when necessary
—> full course should be completed
If not completed the immune system will not be able to destroy all the bacteria, and so they can infect other people and grow resistant
Hand washing
Wash their hands with alcohol based gels and chlorine disinfectant to destroy any pathogens. In addition they should wear appropriate clothing to avoid spreading pathogens
Isolation of patients
HAI infected patients need to be isolated in high level of hygiene and disinfect rooms as to prevent the spread of infection
Prevention of infection coming into the hospital
Patients carrying communicable disease need to be treated of them first before they are treated of the main infection
As to not spread infection. Moreover unwell people should not visit patients and when visiting visitors should maintain a high level of hygiene
Monitoring levels of HAI
Measuring and reporting is important as it is attracts attention so that more effort are put to solve the problem
Explain how a mutation in the genome could lead to the host suffering from influenza more than once
On the first infection the host immune system makes antibodies and memory cells against the virus antigens
If the same antigens are detected a secondary response is rapid and prevents symptoms developing
A mutation will alter the shape of the antigens
The host memory cells will no longer recognise the antigens
Suggest why this might lead to secondary infection by bacteria
Ciliated cells move mucus up the respiratory tract
Infected cells die and the mucus stops moving
Bacteria are caught in the mucus
Ence ideal conditions and reproduce quickly
Bacteria experi
Decomposition in nature
Conditions for recycling nutrients
Warm and moist
—> higher temperature —> greater enzyme activity
—> not too high it going to denature
Moist
- makes dissolving easier
-prevent microorganisms from completely drying
Plenty of oxygen
-decays faster as decomposed respire faster
Factors that affect the time of death fat level
Body fat slows down cooling because it acts as an insulator, and so a fatter person will cool slower than the thinner one
Factors that affect the time of death mode of death
Someone who died in a cold area will cool faster than in a warm area
Factors that affect the time of death surrounding temperature
Someone who died in a cold area will cool faster than in a warm area
Factors that affect the time of death surface area ; volume
Smaller people cool faster as diffusion is more sufficient
Factors that affect the time of death clothing
Clothes and covering insulate the body and so it cools slower
Rigor mortis
What are vaccine
Contains antigens whichare put into the body for active artificial
Vaccines contain dead or weaken pathogen less harmful strain
How vaccination work
Vaccination produce long term immunity as they cause memory cell to be created
The immune system recognise the antigens when re-encountered and produce antibodies in a faster, stronger secant response
