Topic 4 - Cells and Tissues Flashcards
Lectures 12-14
How is a blood film set up?
- Drop of blood set on one end of microscope slide
- Cover slip used to spread it in a single thin layer
- Slide is air dried, fixed and stained
- Staining helps identify the different cells
What are blood films used for?
Diagnosis of haemotological disorders and parasites
What colours are blood cells dyed under Romanowsky dyes?
- RBC/eosinophil granules = pink/red
- DNA/RNA - blue/purple
- Platelets (and other cytoplasmic granules) = blue/purple
What are the 5 types of WBCs?
- Neutrophils
- Lymphocytes
- Monocytes
- Eosinophils
- Basophils
What are neutrophils?
WBC that defend against bacteria and fungi through chemotactic and phagocytic destruction.
How are neutrophils adapted to defend against fungi/bacteria?
- Granular cytoplasm with microbicidal agents
- 2-5 lobed nucleus
- 8-10 hours lifespan in circulation
- make up 50-70% of total WBC
What are lymphocytes?
WBC that function in adaptive immune responses - detect antigens and produce antibodies
What are the 3 types of lymphocytes and what do they target?
- T lymphocytes (cell mediated immunity)
- B lymphocytes (humoral immunity)
- NK cells (virus infected cells and tumour cells)
What is humoral immunity?
The aspect of immunity that is mediated by macromolecules found in extracellular fluids such as secreted antibodies, complement proteins, and certain antimicrobial peptides.
What is cell mediated immunity?
An immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen
What are monocytes?
WBCs that play a role in defense against bacteria and fungi by antigen presenting, chemotactic, phagocytic destruction.
How are monocytes adapted to defending against bacteria/fungi?
- Granular cytoplasm with vacuoles
- Nucleus in kidney shape
- Circulate for 1-3 days
How are lymphocytes adapted to adaptive immune responses?
- Large round nucleus
- Little cytoplasm
- Long lifespan (years)
What are basophils?
WBCs that defend against parasitic infection by binding IgE
How are basophils adapted to defending against parasitic infection?
- Highly granular cytoplasm that obscures nucleus
- Cytosol contains histamine, serotonin and prostaglandinds
- Bi or tri lobed nucleus
- Lifespan 1-5 days
