Week 3 - Chronic Inflammation Flashcards
In response to what substance do blood monocytes become tissue macrophages?
Gamma-interferon
What type of necrosis do the granulomas of tuberculosis show?
Caseous necrosis
What are eosinophils typically associated with?
- Allergic conditions
2. Parasites
What are the typical giant cells found in tuberculosis?
Langhans type giant cells
What is the dominant cell type in chronic inflammation?
Macrophages
What types of persisting injurious agents can trigger chronic inflammation?
- Microorganisms, e.g. bacteria
- Sterile but irritating tissue, e.g. necrotic tissue
- Foreign body/crystalline substance
- Antigen, e.g. autoimmune disease
In what ways can chronic inflammation arise?
- Carrying on from acute inflammation - most common
- Develops without preceding acute inflammation, e.g. chronic infections - TB, autoimmune conditions - RA, prolonged exposure to toxic agents - silica
- Develops alongside and is superimposed on acute inflammation, e.g. ongoing bacterial infection
Which cell types are primarily seen in chronic inflammation under the microscope?
Mononuclear cells: macrophages and lymphocytes
For how long do monocytes circulate in the bloodstream before they enter tissues?
Six days
State some functions of macrophages.
- Phagocytosis: although not always as effectively as neutrophils, better at destroying difficult to kill bacteria, e.g. Mycobacterium tuberculosis
- Secretion of substances that summon and activate other cells
- Presenting antigens to immune system + initiation of the immune response
- Inducing fibrosis
- Inducing fever, acute phase reaction and cachexia
- Stimulating angiogenesis which is important in wound healing
State the functions of lymphocytes.
- Processing antigens
- Secreting antibodies: B lymphocytes that have undergone differentiation - plasma cells
- Producing cytokines that influence other inflammatory cells
- Killing cells: NK cells - attack virus-infected cells and sometimes tumour cells
