Immunology Flashcards
What are the physical barriers of the immune system?
Skin
Cilia
Sneezing and coughing
What are the chemical barriers of the immune system?
Tears
Breast milk
Sweat
Saliva
Acidic secreitions
Semen
What are leukocytes?
White blood cells
How are white blood cells derived?
From undifferentiated stem cells in the bone marrow
What are the 5 white blood cells?
Neutrophils
Eosinophils
Basophils
Monocytes and macrophages
Natural killer cells
What are neutrophils? What is their role?
Engage in phagocytosis
Short-lived and can only engulf a few pathogens before breaking down or being exuded as pus
What are Eosinophils? What is their role?
Secrete agents that destroy larger pathogens, especially parasite
What are basophils? What is their role?
They secrete heparin and histamine
They perform some signalling roles shared with other leukocytes
What are monocytes and macrophages? What is their role?
Monocytes are large and mobile. They have adaptive immune functions and can perform phagocytosis.
Some monocytes embed in tissue and become macrophages.
What are natural killer cells? What is their role?
Rare in blood, more prevalent in lymph
Through activating and inhibiting receptors they are able to identify cells infected by certain viruses and tumour cells
Secrete granules of proteins capable tricking the cell to kill itself
What is acquired immunity?
Immunity that we acquire as we go through live.
Where are T-cells matured?
Thymus
What is the role of T-cells? (3)
- Cell destruction -
T-cells bind to the target cell and release toxic substances which are capable of destroying it. - Control of the immune system -
Stimulate the immune system - Memory -
They remember antigen receptors which have been previously detected in the immune system.
They then produce a group of lymphocytes which can stimulate the parts of the immune system that are able to counter these antigens.
Where do B-cells mature?
Bone marrow
What is the role of B-cells?
They can detect novel pathogens but also secrete antibodies
What are antigens?
Antigens are on the outside of a cell or virus which if the body does not recognise can provoke an immune response.
What are antibodies also known as?
Immunoglobulins
What are immunoglobulins made of?
Y shaped structures that have two paratopes, one on each tip.
Each paratope is specific to one antigen but the main body of the antibody is identical to all the other in its class.
Paratopes are the lock to the epitope, key. The epitope is usually a part of a protein found on the cell membrane.
What do immunoglobulins do? (3)
- Neutralise -
Physically grab on to viral or bacterial cell surfaces, making them unable to attack host cells - Agglutinate -
Make target cells stick together, producing a bigger target for phagocytosis - Precipitate -
Make soluble targets into an insoluble clump to create an easier target for phagocytosis
What are vaccinations?
Used to prevent the spread and damage of several diseases.
How do vaccinations work?
Vaccines contain either dead or attenuated strains of a pathogen.
They stimulate the innate immune response.
This stimulates the acquired system to recognise the pathogen and make antibodies.
These are then stored by B-lymphocytes for later.
If you are exposed to the pathogen again, the acquired immune system responses within 2 days and prevents it fully taking hold.
What is antimicrobial resistance?
Ability of a microbe to resist the effects of medication previously used to treat them.
What are the 3 causes of antimicrobial resistance?
Overuse
Misuse
Other factors
E.g., inadequate monitoring, Infection prevention, Overcrowding in hospitals, Travel
What is humoral immunity?
Humoral immunity is the process of adaptive immunity manifested by the production of antibodies by B lymphocytes
