1. A specific immune response singles out one particular agent that can harm us and responds to that. For example if we catch a certain virus, our specific immune system will destroy that particular virus. Specific immune responses in our body are carried out by two main types of cells: Specific Immune Response

2. One type are called B lymphocytes, or simply, B Cells. B Cells Specific Immune Response

3. And another type are called T lymphocytes, or simply T cells. T Cells B Cells Specific Immune Response

4. B cells and T cells are both types of white blood cells. T Cells B Cells Specific Immune Response White Blood Cells

5. Here, we’ll introduce you to B cells and what they do. B cells are made in the bone marrow, and circulate in both the lymphatic system and the blood stream.

6. The lymphatic system is a system of vessels which carries a fluid called lymph around the body. The lymphatic system plays a very important role in immunity. Many B cells are found here. The Lymphatic System

7. The circulatory system is just another name for our blood stream. B cells also circulate through the bloodstream to all parts of the body. They can quickly be carried to places they are needed. The Circulatory System

8. An antigen is defined as any substance that causes an immune response in the body. Antigens can be such things as toxic chemicals, bacteria, viruses, pollen, or mold. An antigen is defined as any substance that causes an immune response in the body

9. These diagrams can represent antigens that have made their way into our body. An antigen is defined as any substance that causes an immune response in the body

10. These little red marks represent special molecules antigens have on their surface. These little red marks represent special molecules antigens have on their surface. These can be called markers. Each type of antigen has its own specific markers which can be used for identification.

11. These can be called markers. These little red marks represent special molecules antigens have on their surface. These can be called markers. Each type of antigen has its own specific markers which can be used for identification.

12. Each type of antigen has its own specific markers which can be used for identification. These little red marks represent special molecules antigens have on their surface. These can be called markers. Each type of antigen has its own specific markers which can be used for identification.

13. All of the antigens shown here are the same type, so they have identical little red markers shown on them. These little red marks represent special molecules antigens have on their surface. These can be called markers. Each type of antigen has its own specific markers which can be used for identification.

14. Here is a B cell

15. The surface of B cells has Y-shaped molecules attached to it. These are called antibodies. These antibodies are attached to the cell’s outer membrane. As we will see, free antibodies that are not attached, can also exist. Antibodies

16. On the ends of these antibodies there are special receptors. Our bodies produce thousands of different varieties of B cells. Each variety has it’s own special receptors. Receptors

17. This particular B Cell has receptors that will (click) bind to the molecules on the surface of this antigen. No other type of B cell will have receptors that will bind to this particular antigen. (CLICK) antigen I’m SPECIAL!

18. We can watch our B cell binding to these antigens. When it is connected to antigens, this B cell is ready to be activated.

19. Chemical signals are sent to this B cell from other cells called T cells. You will learn more about T cells in another video. Being connected to antigens and receiving these signals from T cells, stimulates this B cell to make many clones, or identical copies of itself. chemical signals from T-Cells

20. Here are a couple of those copies.

21. Some of the copies that are made become factories which can produce thousands of free antibodies. A factory for producing antibodies

22. Watch as this cell keeps on producing these Y shaped antibodies. Notice, these antibodies are free to move around at this point. (At the end say  )They can, however, bind to the molecules on the surface of an antigen they are matched to.

23. Watch as three antibodies bind to this antigen

24. After this B cell has produced enough antibodies, it will self-destruct.

25. (watch then click)

26. This antigen now has antibodies sticking to it. These can disable it from doing harm in our body. They also identify it as something that can be attacked by other white blood cells. disabled and marked for an attack

27. Here is a macrophage that comes along and destroys this structure.

28. Antiobdies can also do other things with antigens. Here is an antibody and two antigens.

29. This single antibody can connect to both of these antigens.

30. So this antibody has clumped two of these antigens together. What is formed is quite a large structure. This structure is too large to pass through cell membranes, so the antigen is now unable to infect new cells. This structure is too large to pass through cell membranes.

31. It is also identified as being able to be attacked and destroyed by other white blood cells. Marked for attack!

32. Most of these particular B cells that were made will self-destruct once the immune response is over and the antigens have been destroyed. However a few B cells of this variety remain in the body for a long time.

33. These are called memory B cells. A Memory B Cell

34. So if that same antigen ever enters our body again, at a later time (click), we already have some B cells that (click) have just the right receptors to attach to it and disable it before it does any harm (click). A Memory B Cell Gotcha! I’m back!

35. As we are exposed to more types of antigens, our body responds with B cells that will :  Bind to them.  With the help of T-Cells, make many copies of themselves.  Some of these copies produce antibodies which disable the antigens and identify them for attack.  Some copies of these B cells will stay in the body as Memory B Cells.  These will increase the body’s immunity to future attacks by the same antigen.

36. Bind to them. As we are exposed to more types of antigens, our body responds with B cells that will :  Bind to them.  With the help of T-Cells, make many copies of themselves.  Some of these copies produce antibodies which disable the antigens and identify them for attack.  Some copies of these B cells will stay in the body as Memory B Cells.  These will increase the body’s immunity to future attacks by the same antigen.

37. and with the help of T-Cells, make many copies of themselves. As we are exposed to more types of antigens, our body responds with B cells that will :  Bind to them.  With the help of T-Cells, make many copies of themselves.  Some of these copies produce antibodies which disable the antigens and identify them for attack.  Some copies of these B cells will stay in the body as Memory B Cells.  These will increase the body’s immunity to future attacks by the same antigen.

38. Some of these copies become factory cells which produce antibodies. These antibodies disable the antigens and identify them for attack. As we are exposed to more types of antigens, our body responds with B cells that will :  Bind to them.  With the help of T-Cells, make many copies of themselves.  Some of these copies produce antibodies which disable the antigens and identify them for attack.  Some copies of these B cells will stay in the body as Memory B Cells.  These will increase the body’s immunity to future attacks by the same antigen.

39. And some copies of these B cells will remain in the body and act as what are called Memory B Cells. As we are exposed to more types of antigens, our body responds with B cells that will :  Bind to them.  With the help of T-Cells, make many copies of themselves.  Some of these copies produce antibodies which disable the antigens and identify them for attack.  Some copies of these B cells will stay in the body as Memory B Cells.  These will increase the body’s immunity to future attacks by the same antigen.

40. These will increase the body’s immunity to future attacks by the same antigen. If the same antigen enters our body at a future time, these memory B cells will recognize it and disable it before it can do much harm. As we are exposed to more types of antigens, our body responds with B cells that will :  Bind to them.  With the help of T-Cells, make many copies of themselves.  Some of these copies produce antibodies which disable the antigens and identify them for attack.  Some copies of these B cells will stay in the body as Memory B Cells.  These will increase the body’s immunity to future attacks by the same antigen.

41. If you like, you could pause the video, take a screen shot of this and copy it to study from. As we are exposed to more types of antigens, our body responds with B cells that will :  Bind to them.  With the help of T-Cells, make many copies of themselves.  Some of these copies produce antibodies which disable the antigens and identify them for attack.  Some copies of these B cells will stay in the body as Memory B Cells.  These will increase the body’s immunity to future attacks by the same antigen.

42. Acknowledgements for Images Used "Diagram of the lymphatic system CRUK 041" by Cancer Research UK - Original email from CRUK. Licensed under CC BY-SA 4.0 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Diag ram_of_the_lymphatic_system_CRUK_041.svg #/media/File:Diagram_of_the_lymphatic_syste m_CRUK_041.svg

43. Acknowledgements for Images Used "Circulatory System en" by LadyofHats, Mariana Ruiz Villarreal - Did myself based in the information and diagrams found in:"gray's anatomy" thirty sixth edition by Williams & Warwick."Sobotta Atlas der Anatomie des menschen" volume 1 and 2 18.Auflage by Urban & Schwarzenberg"Atlas fotografico de anatomia del cuerpo humano" 3a edicion by Yokochi, Rohen & Weinrebmultiple websites included:[1], [2], [3], [4], [5], [6], and others.This file has Outlined text. if you seek an Editable text version please use File:Circulatory System en edited.svg. or open one of the older versions of this file (down on the file history)-LadyofHats (talk) 21:42, 30 March 2010 (UTC). Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Circulatory_System_ en.svg#/media/File:Circulatory_System_en.svg