Defence Cells Flashcards
What is immune dysregulation?
When the immune system is not functioning normally (impairment of the immune system)
Where do nearly all defence cells originate?
In the bone marrow
What are haematopoietic cells?
Cells that can differentiate into any type of blood cell: RBC, WBC or platelet
Where do lymphoid cells originate?
In the lymph glands
Where do myeloid cells originate?
In the bone marrow
What are common myeloid precursors?
- Macrophages
- Neutrophils
- Mast cells
- Basophils
- Eosinophils
- RBC
What are common lymphoid precursors?
- B cells
- T cells
Are neutrophils granulocytes?
Yes, they have secretory granules in them
- these contain degradative enzymes and antimicrobial substances within them
Which cells are the most numerous and important cells in innate immune responses?
Neutrophils
Where are neutrophils found in the body?
- They circulate in the blood and move into tissues when requires
- Healthy people will have millions of neutrophils in the body
What is meant by neutrophils being phagocytic?
They take up and destroy organisms by phagocytosis
What is chemotaxis?
The movement of an organism in response to a chemical stimulus
Which cells circulate in the blood as precursors called monocytes?
Macrophages - they become macrophages once they migrate into the tissue
Are macrophages early responders to infection or tissue damage?
Yes, they are long lived with multiple functions
What is it meant by macrophages being ‘antigen presenting cells’?
They are able to phagocytose but can also present antigens to other cells
Are mast cells granulocytes?
Yes, they are best known for their role in allergy as they produce histamine
Are mast cells early responders to infection or tissue damage?
Yes, they migrate from blood and differentiate into tissues
What to mast cells protect against?
Pathogens - particularly larger pathogens e.g. parasitic worms
Are Eosinophils granulocytes?
Yes, they contain degradative enzymes and antimicrobials
Do eosinophils contribute to allergy?
yes
Why are eosinophils thought to play a major role in defence against parasites?
Because they are larger than neutrophils so can ingest larger threats