Lecture 2 - Cells and Tissues of the Immune System Flashcards
Does lymph circulate like blood?
No. It is an open-ended system
Parts of a lymph node 1) 2) 3) 4) 5)
1) Capsule
2) Cortex
3) Follicle
4) Paracortex
5) Medulla
Which cell is predominant in the paracortical areas of lymph nodes?
T cell
Which cell is predominant in the follicular areas of lymph nodes?
B cell
Which cell type is predominant in the medullary cords of lymph nodes?
Macrophages and dendritic cells
What happens in the red pulp of the spleen?
Old erythrocytes are digested by macrophages
Types of granulocytes
1)
2)
3)
1) Basophils
2) Eosinophils
3) Neutrophils
Function of basophils
1)
2)
1) Promote allergic response
2) Promote anti-parasitic immunity
Where are neutrophil granulocytes normally found?
In blood
In infected tissue
Where are neutrophils produced?
Bone marrow
How long do neutrohphils live?
7-10 days
Neutrophil disorders
1)
2)
1) Myeloid leukaemias
2) Chronic granulomatous disease
Why do eosinophils stain purple with eosin stain?
Granules contain arginine-richbasic protein
How common are eosinophils?
~5% of cells in blood
Where are eosinophils most commonly found?
In tissues
Types of granules in eosinophils
1)
2)
1) Microbicidal - toxic proteins, radicals
2) Immunomodulatory - Leukotrienes, prostaglandins, cytokines
Which cytokines do basophils release?
IL-4, IL-13
Possible role of basophil
Bias T cell differentiation to Th2
Where are mast cells most commonly found?
Connective tissues
Cytokines released by mast cells
IL-4, IL-13
Factors released by mast cells
IL-4, IL-13, histamine
Functions of dendritic cells
1) Antigen presenting
2) Bias T cell type through signalling molecules
Natural killer cell role
Kill cells without self identification surface markers (MHCI)
What restricts CD4 T cells?
MHCII restricted
What restricts CD8 T cells?
MHCI restricted
What endows T cells with high specificity to antigen?
Alpha/Beta TCR
