009 Cells and tissues of the immune system Flashcards
List the innate immune cells
Granulocytes (neutrophils, eosinophils, basophils)
Neutrophils
Macrophages (monocytes)
List the adaptive immune cells
Lymphocytes (T, B cells)
What is the main innate immune response?
Neutrophils (80%)
What are primary lymphoid organs?
Bone marrow and thymus
What are secondary lymphoid organs
Encapsulated: Spleen, lymph nodes
Unencapsulated: MALT
What do eosinophils target against and how?
Their granulocytes contain alkaline substances (cationic granules), which can target worms.
What do basophils contain and what effect does it produce?
Their granulocytes contain heparin and vasoactive agents that causes inflammation.
What are lymph nodes made of?
Thin collagen fibre that acts as a sieve to trap antigens in the lymph nodes.
What occurs in the paracortex of the lymph node?
T-cell activation by interdigitating dendritic cells
How do lymphocytes leave circulations into lymph nodes?
Through high endothelial venules by homing system. Addressins on the blood vessel will home the integrins found on the lymphocyte, slowing it down.
How long do neutrophils live for?
<24 hours
How can you identify neutrophils on a histology slide?
They have irregular nuclei that may look like there are a few large nuclei.
How do neutrophils attack pathogens?
Secrete granules containing hydrogen peroxide. This converts oxygen into hypochlorous acid.
What is the main function of macrophages?
Cleaning up cell debris from the body system
Where are macrophages present?
In tissues. In blood, they are mainly in their precurser monocyte form.
