Lymphoid Tissues Flashcards
What are primary lymphoid tissues responsible for?
Development of lymphocytes like B and T cells.
What are secondary lymphoid tissues do?
Provide residence for B and T cells, so that antigens brought by professional APCs (Antigen Presenting Cells) can stimulate these cells to fight the pathogen.
What are the two primary lymphoid tissues?
- Bone marrow
2. Thymus
What is stem cell is in the bone marrow that gives rise to progenitor cells for B and T cells.
Pluripotent hematopoietic stem cells.
Where do B cells change into plasma cells?
In secondary lymphoid tissue when they become activated by antigens, they then become plasma cells.
Where do T cells continue their maturation before they take residence in secondary lymphoid tissue?
Thymus
T cells start development within the bone marrow then migrate to the thymus.
Name some examples of secondary lymphoid tissues.
Gut-associated lymphoid tissue (GALT).
Adenoids,
Spleen,
Lymph nodes,
Appendix
Bronchial-associated lymphoid tissue (BALT)
Skin-associated lymphoid tissue (SALT), etc.
What happens to a person’s thymus’ size as they age?
It decreases in size.
Does an aging person’s changing thymus impact their immune response as they age?
No, it is still able to produce enough functional T cells.
What makes the spleen unique as a lymphoid tissue?
- Creates the largest quantity of B and T cells. (or rather it must activate)
- Filters out pathogens in blood system (whereas other 2nd-ary lymph tissue filters lymph draining from infected tissues.
What is the fluid called that circulates in lymphatic vessels?
Lymph
Only difference between lymph, extracellular fluid, and plasma is location.
T/F. Lymphocytes (B and T cells) travel through both blood and lymph.
True, even though the majority reside in 2nd-ary lymphoid tissue awaiting activation many are in peripheral circulation.
What happens if a lymphocyte does not become activated?
It will leave the 2nd-ary tissue through the lymphatic vessels searching out any potential infections. If still not activated by the time it makes its way to a vein where it enters the blood circulatory system it will go through the blood then back to tissue and do the cycle all over again until it becomes activated or dies.
