Lymphatic organs Flashcards
Types of lymphoid organs
Primary and secondary
Primary lymphoid organs
Bone marrow and thymus
All lymphatic cells originate in
Bone marrow
Where are two possibilities for a lymphoid progenitor after it has been formed
- Stay in bone marrow and differentiate into mature naive B cell or 2. Migrate to thymus where it will mature into a naive T-cell
What is a thymocyte, and where are most of them found
An immature T-cell found in cortex of thymus (mainly)
What the two main structures of the thymus
Cortex, Medulla
where are stromal thymic cells located, and what three types of cells can they be
Located amongst immature t cells(thymocytes) in cortex of thymus, epithelial cells, dendritic cells and macrophages all form part of stromal thymic cells
what is Hassall’s Corpuscle, what does it do
A secretory gland (paracrine) that secretes chemical signals indicating dendritic cells in thymus to induce activation of T cells
What is the main CD in a maturing B cell in bone marrow
CD9
Main CD on Hematopoyetic Progenitor. Cytokines for diferentiation into myeloid germline, cytokines for differentiation into lymphoid progenitor
CD48, Myeloid–GM-CFS and G-CSF and IL-3, Lymphoid IL-7
Another name for secondary lymphoid organ, whats the main thing that happens in them
Peripheral lyphatic organs, the presentation of antigaens to naive T and B cells completing their activation
what is a naive B or T cell, what do they differentiate to with the correct signals?
Differentiated cells that haven’t been presented an antigen yet, with correct signals and interactions the will differentiate into B cells or Effector(cd4+) or Cytotoxic(cd8+) t cells respectively
two main types of peripheral lymphoid organs
Organs (spleen, lymph nodes, malt) and Vessels carrying lymph
Location of pathogen and active lymphoid organs; a.lymph nodes b. spleen c.Malt
a. tissue, b. blood c. mucosae (gastrointestinal, genitourinary, respiratory, oral and head)
Main 2 functions of Lymphatic vessels
Transport of Ag´s and APC’s and drainage of fluid for interstitial space
The______Drains the lymphatic system into the_____ of the heart
Thoracic Duct, Vena cava
Three layers of lymph node
Outer to inner–Cortex, Paracortex, Medulla
Last stop for activated B and T cells or macrophages found in lymph node.
Medula, then leave through efferent lymphatic vessels
function of secondaary lymphoid organss
Antigen presentation and thus, activation of naïve B and T cells gas
What can we find in cortex of the lymph node
Primary follicles composed of mainly b cells and secondary (mature ) follicles with germinal centers, where B cells differentiate and mutate for clonal selection
The t cell zone in lymph nodes and in spleen
Paracortex and periarterial lymphatic space (PALS) respectively
naive t and b cells enter through ____ And leave through the ______ APC´s and antigens enter the lymph node through______
artery, efferent lymphatic vessel, afferent lymphatic vessels
Two main functions of the spleen
Filtration of blood and thus antigens in blood, erythrocyte clean up
What happens in red pulp, What can we find in this pulp
Erythrocytes go here to die, macrophages and erythrocytes can be found here
