Lymphocytes a limp fuh site is a specialized white

Info icon This preview shows pages 643–645. Sign up to view the full content.

View Full Document Right Arrow Icon
Lymphocytes A (LIMP-fuh-site) is a specialized white blood cell that coordinates and performs many of the functions of specific immunity . There are two types of lymphocytes: T cells and B cells. T CELLS AND B CELLS There are different types of T cells with different functions. They all work together to protect against infection. Helper T cells trigger the production of B cells and killer T cells. Killer T cells attack and destroy infected body cells. Killer T cells don’t attack the pathogens themselves, only the infected cells. lymphocyte immunity antigen 630 Chapter 24 Communicable Diseases The immune response is a complex interaction between your body and an invading pathogen. It can be broken down into eight distinct stages. 1. Pathogens invade the body. 2. Macrophages engulf the pathogen. 3. Macrophages digest the pathogen and T cells recognize antigens of the pathogen as an invader. 4. T cells bind to the antigens. 5. B cells bind to antigens and helper T cells. 6. B cells divide to produce plasma cells. 7. Plasma cells release antibodies into the bloodstream. 8. Antibodies bind to antigens to help other cells identify and destroy the pathogens. 1 2 3 4 health.glencoe.com TOPIC The Immune System Go to health.glencoe.com and click on Web Links to find out more about how the immune system works. ACTIVITY Using the informa- tion you find at these links, write a short story about an immune system fending off an infection, from the point of view of a lymphocyte.
Image of page 643

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Suppressor T cells coordinate the activities of other T cells. They “turn off” or suppress helper T cells when the infection has been cleared. In conjunction with the work of T cells, lymphocytes called B cells produce antibodies. An is a protein that acts against a specific antigen . Each B cell is programmed to make one type of antibody, specific to a particular pathogen. Some antibodies attach to foreign antigens to mark them for destruction. Some destroy invading pathogens. Others block viruses from entering body cells. The Role of Memory Lymphocytes our immune system actually has a “memory.” Some T cells and Y B cells that have been activated by antigens become memory cells . These memory cells circulate in your bloodstream and through the lymphatic system, shown in Figure 24.4 on page 632. When memory cells recognize a former invader, the immune system uses antibodies and killer T cells in a quick defense to stop it. For exam- ple, if you have had measles or an immunization against measles, your immune system remembers the antigens for the measles virus. If it enters your body again, antibodies will attack the virus imme- diately, protecting you from becoming ill. Active Immunity The immunity your body develops to protect you from measles and from other diseases is called active immunity. Naturally acquired active immunity develops when your body is exposed to antigens from invading pathogens. Artificially acquired active immunity develops in response to a a preparation of dead or weakened
Image of page 644
Image of page 645
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern