Immunity Flashcards
What is innate immunity?
First line of defence from infection
Limited specificity
Does innate immunity change over time or after exposure?
No
Is innate immunity different in individuals of the same species?
No it is exactly the same in all individuals of the same species
Does innate immunity have an immunological memory?
No
Is the innate immune system only in operation when infection occurs?
No it is present in all individuals all the time
What does our adaptive immune response respond to?
Specific non-self antigens
What is required by the adaptive immune response for a fully effective response?
Prior exposure
How long after infection will the adaptive immune response start working?
4-5 days
Does the adaptive immune response have an immunological memory?
Yes
What physical barriers does innate immunity provide?
Keratinised epithelium
Mucosal tissues - trap pathogens and cilia waft into airways to breathe out
What chemical barriers does innate immunity provide?
Extremes of localised pH - change in pH kills bacteria
Biochemicals in tears and saliva
Increase body temperature during infection to kill bacteria
Is phagocytosis an innate or adaptive immune response?
Innate
What cells carry out phagocytosis?
Neutrophils, macrophages, eosinophils
What common feature do all phagocytic cells have?
Granulated cytoplasm
What is the function of monocytes?
Move around in the blood and become macrophages when activated in the tissue
Why is simple phagocytosis not enough for some bacteria?
Sometimes they are not recognised as foreign because of the polysaccharide capsule on the bacteria
How does phagocytosis combined the innate and adaptive immune systems?
Sometimes bacteria aren’t recognised because of the polysaccharide capsule so they are coated in antibodies (opsonised) so they can be phagocytosed.
Antibodies are a product of the adaptive immune system
What does the complement system do when it is activated?
Recruits inflammatory cells
Opsonisation of pathogens
Perforate pathogen cell membrane
What cell type mediated adaptive immunity?
Lymphocytes
What is humoral immunity?
Molecular immunity from antibodies from B-lymphocytes
What is cellular immunity?
Uses activate T lymphocytes to help B cell differentiation and kill pathogens
What is the function of dendritic cells?
Antigen presenting cells and present them to T-cells
What is the function of mast cells?
Filled with basophil granules - releases histamine and causes inflammatory response
How can lymphocytes be identified?
Very large nucleus
How can plasma cells be identified?
Excentric nucleus
Lots of RER - so lots of proteins can be made
How do antibodies work to kill bacteria?
Opsonisation
Agglutination –> can swallow and kill in stomach acid
Neutralisation –> neutralise toxins
Activate complement system
What is a monoclonal antibody?
Manufactured in lab to be highly specific to 1 antigen
Why is antigen presenting a key step in adaptive immunity?
It starts the cycle
Antigen presenting activates the T-cells
They differentiate into T-killer cells which kill pathogen
T-helper cells stimulate differentiation of B-cells into plasma or memory cells
Plasma cells secrete antibodies
Why is the major histocompatibility complex (MHC) gene highly polymorphic?
To provide the population with a variety of ways to handle infection so more are likely to survive
What gene is sequenced when matching a donor for a transplant?
MHC
What is the difference between the primary and secondary immune response?
secondary antibody production is quicker, more substantial and better quality
Why does inflammation occur?
To move neutrophils to the site of infection
How are degraded neutrophils removed?
Macrophages
What is a consequence of chronic inflammation in teeth?
Too many neutrophils for too long, degrade collagen this leads to periodontitis
What are the pillars of inflammation?
Pain, redness, heat, swelling and loss of function
