Immune cells Flashcards
What are the functions of the immune system?
- Prevent and detect infections
- stopping living bodies from decomposing
- Rejection of tissue graphs
What are the three main components of the immune system?
- Physical barriers
- Cells and tissues
- Soluble factors
How do epithelial cells protect against microorganisms?
- Block entry of microorganisms
- Produce antimicrobial proteins and mucins
- Produce regulatory proteins such as cytokines and chemokines
What are the characteristics of neutrophils?
- Small cells of neutral staining with a lobed nucleus
- Actively phagocytic
- 50-70% of blood leucocytes
- Contains granules of elastase and antimicrobial proteins
- 5 day lifespan
What are the properties of eosinophils?
- acidic staining
- 1-6% of blood leucocytes with a lifespan of around 12 h
- Found in lower gut, spleen, lymph nodes and ovary
- Release peroxidase and anti-parasite toxins
- Involved with inflammatory response to parasites, allergies and asthma
What are the properties of basophils?
- Bi-lobate nuclei with a granular cytoplasm
- Rarest of all blood leucocyte types
- lifespan of 60-70hours
- Granules release histamine, heparin, cytokines,
serotonin & chondroitin - Involved in inflammation & allergic reactions
via IgE binding
What are the properties of monocytes?
- Unlobed with few granules
- 3-8% of blood leucocyte
- 3 subsets distinguished by surface receptors
- Phagocytic, present antigens and produce cytokines
- Migrate to tissues where they mature into other cell types
What are the properties of lymphocytes?
- Small with a large nucleus and little cytoplams
- Can be B or T
- Non phagocytic
- Main effectors of the the adaptive immune system
What are the properties of natural killer cells?
- Comprise of 15% of blood leucocytes
- Kill other cells without antibodies
- Lymphocyte-like but granules containing perforin & granzymes
- Produce cytokines, such as TNFα, interferon & some interleukins
What are the properties of macrophages?
- Large phagocytes which consume bacteria, dead cells, fragments and debris
- Live for several months
- Derived from monocytes
- Occur ar site of infection in inflammation but also aid in adaptive immune system
What are the properties of dendritic cells?
- Small with stellate appearance
- Love for few days/weeks
- Sample environment for pathogens
- Found in tissues with external surfaces
- Migrate to the lymph node when they then activate the innate immune system
What are the properties of mast cells?
- Highly granulated basophilic cells which are absent from circulation
- Found in tissue and mucose
- Rich in histamine and heparin
- Degranulate upon ingury/biding to IgE
- Involved in defense against parasites and allergies
What cells are included in the myeloid lineage?
- Cells involved in inflammation
- Mast cells
- Dendritic cells
What cells are included in the lymphoid tissues?
- Cells of the adaptive immunity (lymphocytes)
- NK cells
What sites are important for the production of immune cells?
Bone marrow: inflammocyte and B cell production
Thymus: T cell maturation and selection
Lymph nodes, appendix and lymphatic vessels
