Flashcards in Cells of the immune system Deck (61)
where are cells of the immune system found?
- Circulate in the bloodstream
-Migrate into tissues to detect foreign antigens
-accumulate in specialised organs to develop and differentiate
Name 5 white blood cells.
where do all cells from the immune system stem from?
Haemopoietic stem cell
what is a precursor of platelets?
what is the precursor of macrophages?
Name 3 antigen presenting cells.
what leucocytes makes up the lymphoid lineage and what is its function?
- involved in recognition and effector functions
what leucocytes makes up myeloid lineage?
-Granulocytes (short lived)
Name the 3 granulocytes and their function.
-Neutrophils (comprise 60-70% blood leucocytes)
-Eosinophils (2-5% blood leucocytes)
-Basophils (Mast cells) (<0.2% blood leucocytes)
Involved in effector function
what is monocytes function?
Involved in recognition and effector functions
Remove particulate matter e.g. microbes or aged RBC
How are neutrophils characterised?
how do neutrophils enter tissues?
Adhere to endothelial cells lining blood vessels and squeeze between them to leave circulation and enter tissues (diapedesis)
what is neutrophils predominant role?
phagocytosis and destruction of pathogens
what do neutrophil granules contain?
arsenal against microbes:
- Lysosomes - acid hydrolases, myeloperoxidase, lysozyme, defensins
- 2o granules - lactoferrin, lysozyme
what is the role of lactoferrin?
retians iron and makes into a form that the body can use
What type of nucleus does an eosinophil have?
what stains many cytoplamic granules in eosinophils?
what do the crystalloid core of granules in eosinophils contain?
-Major basic protein
= potent toxin for helminth worms
- Eosinophil cationic protein
- Eosinophil-derived neurotoxin
what happens when eosinophils are activated?
-release of granules which leads to killing of large pathogens that cannot be phagocytosed
what cells share characteristics with basophils but are only found in tissues?
what are basophils and mast cells triggered by?
By allergens to release the contents of their granules = allergic response
what type of nucleus does a basophil have?
what is a mast cell's cytoplasm packed full of?
granules filled with histamine and other inflammatory mediators
what type of nucleus does a monocyte have?
Horse shoe-shaped nucleus
Describe the contents of a monocyte.
Many pinocytic vesicles and lysosomal granules
Describe lysosomes importance.
Lysosomes contain peroxidase and acid hydrolases – important for killing phagocytosed microorganisms
what is the major function of macrophages?
disposal of microbes and
dead body cells through phagocytosis
Name the cells of the mononuclear phagocyte system (macrophage like cells).
Liver- Kupffer cells
Kidney- Mesangial cells
Lungs- Alveolar macrophages
Brain- microglial cells
spleen/lymph nodes- sinus macrophages
Peritoneal cavity - serial macrophages
Name 4 accessory cells and their functions.
-Platelets -involved in blood clotting and inflammation
-Antigen presenting cells (APC) - present antigens to T cells
-Mast cells-Structurally and functionally similar to basophils
In connective tissues & close to mucosal surfaces
-Endothelial cells- Receptors recognise certain lymphocytes -
Control lymphocyte traffic and distribution