Immune System: Anatomy & Function Flashcards
What is the positive and negative of the mobility in lymphoid cells?
positive: if have infection in one part of the body, lymphocytes have ability to mobilize & see if are other areas of infection ion the body
negative: if have autoimmune disease against specific antigen, the immune system can find all those sites in the body & cause havoc
why is the heart one of the most important organs?
-because it pumps lymphocytes through the blood
what are the two types of cells in lymphoid tissues?
1) migratory cells (transient)
2) resident stroll cells
* immune response depends on interactions between them*
migratory cells
- in lymphoid tissues
- consist of T & B lymphocytes, dendritic cells, macrophages & differentiated plasma cells
- granulocytes, erythrocytes
lymphoid tissues
-means tissue with many lymphocytes
granulocytes
- bone marrow derived migratory cells in lymphoid tissue
1) neutrophils
2) basophils
3) eosinophils
what are some of the resident stroll cells?
1) epithelial cell populations (thymic epithelium & follicle epithelium)
2) mesenchyme derived
3) connective tissue, smooth muscle, forming capsule & other structures
4) blood supply (endothelium, pericytes)
thymic epithelium function
- a resident stromal cell
- assit in T lymphocyte repertoire selection
follicle epithelium
- a resident stromal cell
- in mucosal lymphoid tissues
- assists in immune surveillance
mesenchyme derived stromal cells?
- resident stromal cells
- provide structural support and cytokines
what does the stromal do?
- is way station for migratory cell populations
1) help provide environment for education of lymphocytes
2) involved in organization of the lymphocytes
3) help lymphocytes know who they need to be communicating with
the bone marrow?
-where most of hematopoiesis takes place
hematopoiesis in adults vs babies?
- process of producing new blood cells
- in adults occurs in bone marrow
- during early develop begins in the yolk sac (early) & fetal liver (later)
- in adults can occur in spleen, but rare unless have pathological conditions which effect bone marrow
what does early fetal liver resemble? why?
-resembles bone marrow since undergoing hematopoiesis (Stem cells differencing into different blood cells)
bone marrow structure?
- has matrix of bone, fat (adipocytes) , and blood vessels
- has diverse cells types, clusteres of myeloid (neutrophil, macrophages) & RBC
How do the hematopoietic stem cells differentiate?
- is not one hematopoietic stem cells that creates many different types of cells
- typically one stem cell makes one type of cell (RBC vs. neutrophil etc)
- end up with clusters where mainly one type of cell is being generated
Megakaryocytes
- specialized bone marrow cells also found in spleen
- multi-nucleated large cells
- produce platelets
Where do plasma cells take up residence?
- differentiated plasma cells working as antibody factories often return to the bone marrow and release abs from there
- are also in many other tissues
primary lymphoid tissue?
- Thymus, Bone Marrow, Spleen (sorta)
- sites of hematopoiese & lymphocyte production/maturation
why is thymus a primary lymphoid tissue?
-even though T cells are made in the bone marrow, they mature in the thymus making it a primary lymphoid tissue
secondary lymphoid tissue?
-where adaptive immune responses are induced by association of lymphocytes & myeloid cells
-lymph nodes, tonsils, spleen
-
1) myeloid cells
2) lymphoid cells
1) include monocytes, macrophages, neutrophils, basophils, eosinophils, erythrocytes, and megakaryocytes to platelets
2) T cells, B cells, and natural killer cells
- dendrites can be derived from BOTH*
why is spleen a secondary lymphoid tissue?
- immune responses immune responses can originate in the spleen
- but can also have some primary functions since is capable of mild hematopoiesis w/ hematopoietic stem cells
tertiary lymphoid tissue?
- lymphoid accumulations organize into this type of tissue at sites of chronic immune responses
- accumulations eventually start to look like secondary tissue, is why considered lymphoid tissue
- doesnt occur normally in peripheral tissues; only occur in chronic immune response