1 / 16

Secondary (2 o ) Lymphoid Tissues

Secondary (2 o ) Lymphoid Tissues. Adapted from Roitt’s Immunology 7-1. What happens in 2 o lymphoid tissues?. Highly efficient in trapping and concentrating foreign substances carried in the blood and lymph

stuart-greene
Télécharger la présentation

Secondary (2 o ) Lymphoid Tissues

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Secondary (2o) Lymphoid Tissues Adapted from Roitt’s Immunology 7-1

  2. What happens in 2o lymphoid tissues? • Highly efficient in trapping and concentrating foreign substances carried in the blood and lymph • They are the main sites of production of _antibodies_ and induction of antigen-specific T cells Why is that important? In a naïve (non-immunized) animal, only 1 in a 1,000 to 1 in 100,000 lymphocytes can recognize the typical foreign invader

  3. Lymph Nodes -The lymph node has specific region for bothT cells (Paracortex) andB cells (Follicle). -Lymphocytesenter the nodevia the bloodwhileantigensenter via the lymph vessels. -Both cell types encounter and respond to antigens in their respective zones. Abbas & Lichtman’s Basic Immunology 1-14 & 1-16

  4. Lymph Nodes Native T cells migrate into the lymph node via the bloodstream and become activated by antigens. The activated T cells exit the nodes via both the bloodstream and the lymph system where they can migrate to peripheral sites of infection. Abbas & Lichtman’s Basic Immunology 1-17

  5. Lymph Nodes • Lymph fluid • Lymph fluid from tissues drains into regional lymph nodes. • APC • APC in the lymph nodes can sample microbial antigens from the lymph fluid. Roitt’s Immunology 7-3

  6. Lymphocyte Recirculation • Naïve lymphocytes • Migrate from lymph node to lymph node looking for an APC to present the correct antigen to it. • Effector lymphocytes • Migrate to the site of infection (T cell) • Secrete antibody from lymphoid organ (B cell) • 80% of lymphocytes migrate to a different lymph node each day Abbas & Lichtman’s Basic Immunology 1-17

  7. Spleen • The T cellsare segregated to theperiarteriolar lymphoid sheath (PALS) • The B cellsare segregated to thesecondary follicle • Same role for blood-borne antigen as lymph node does for lymph-borne antigen. Abbas & Lichtman’s Basic Immunology 1-15

  8. Mucosa-associated Lymphoid Tissue (MALT) • Mucous - acts to trap microorganisms, allowing them to be swept away by ciliated epithelial cells towards external openings • Loose lymphoid aggregates that line mucosal epithelium • Non-encapsulated lymphoid tissues (as opposed to spleen and lymph nodes) • Cells of the MALT tend to recirculate only to other mucosal tissues • Typically found in the GI system where it is termed GALT (Gut-associated Lymphoid Tissue)

  9. Tissues of the Immune System Adapted from Sherwood’s Human Physiology Table 12-1

  10. Next Time • Describe the innate immune system. • Compare and contrast the innate immune system with the adaptive immune system. • Readings: Abbas & Lichtman, Chapters 1 & 2

  11. Objectives • Describe the normal functions of the immune system. • Describe the cells and tissues of the immune system. • Describe the maturation process of lymphocytes.

More Related