Non-Specific Defences Flashcards
What are the two types of innate (non-specific) defence?
Internal and external.
Compare specific and non-specific defences.
Non-specific defences are not selective, and occur during the early immune response. They are ready to go from the moment of birth. Specific defences are the opposite, they need to know what exactly they are dealing with (so they can know if they are capable of dealing) and do not begin to work until after the non-specific defence has tried to eliminate the threat. They must also be trained by lymphocytes to act on threats, are present, but not ready, at birth.
What are the specific defences mediated by?
Lymphocytes drive the specific response.
What are the cells/ processes involved in the non-specific defence?
- Cytokines.
- Complement.
- Inflammation.
What are the cells/ processes involved in the specific defence?
- Cytokines.
- Antibodies.
- B & T lymphocyte cells.
What is the ‘self’ and what happens if our immune system targets it?
The self is out body, our tissues and cells. The immune system should not target the self as it is US, and if it does, it is referred to as an auto-immune disease e.g. T1 diabetes targets beta cells in the pancreas.
What is the ‘non-self’ and what happens if our immune system targets it?
The non-self are foreign cells/ organisms within or on our bodies. If they are perceived as harmful, they are targeted and destroyed by our immune system.
List the central lymphoid tissues.
- Bone marrow.
2. Thymus.
Give the functions of the central lymphoid tissues.
- Leukocytes are formed in the bone marrow.
2. T-lymphocytes are trained in the thymus.
List the peripheral lymphoid tissues.
- Spleen.
- Tonsils & adenoids.
- Peyer’s patches.
- Lymph nodes.
- Appendix.
What is an antigen?
An antigen is any threat, which is then targeted & destroyed by our immune system.
What is an antibody?
An antibody is a protein made by B-lymphocytes to get rid of harmful things.
What is humoral immunity related to?
Humoral immunity relates to the blood, and is associated with antibodies and B lymphocytes.
What does cell-mediated immunity relate to?
Cell-mediated immunity relates to the physical contact with an antigen that is required to remove it. T -lymphocytes require hands-on contact with antigens to destroy them. There is no antibody association here.
How long should acute inflammation last?
Up to three days- longer than this is a sign of chronic inflammation.
What is the function of acute inflammation?
Acute inflammation has a beneficial function, it acts to protect against disease & enable the healing of tissue.
Why is chronic inflammation harmful?
Chronic inflammation (inflammation lasting more than three days) is harmful as it results in lasting damage to inflamed tissues. It is also a feature of many diseases, e.g. rheumatoid arthritis, cancers and any lung diseases.
What triggers inflammation?
- Microbial invasion.
2. Tissue damage.
List the five main events occurring in inflammation.
- Phagocytosis of pathogens.
- Dilation & permeability of capillaries.
- Containment of foreign matter.
- Leukocyte migration & proliferation.
- Continued leukocyte activity.
What is the purpose of pathogen phagocytosis as part of inflammation?
Pathogen phagocytosis around the site of tissue damage reduces the damage that pathogens can potentially do- bacteria and viruses are nipped in the bud.
What is the purpose of the dilation of capillaries during inflammation?
The dilation of capillaries (and other blood vessels) as part of the inflammation process results in an increase of blood flow to the area of damage, thus allowing more leukocytes, defensive proteins and healing cells to access the damaged tissue.
What is the purpose of leaky capillaries during inflammation?
Capillaries are always permeable, but during inflammation they become more so. This allows for leukocytes to exit the bloodstream, and enter the site of damaged tissue in order to aid in repair.