Sarah's third line of defence, also known as the immune response, played a crucial role in fighting off the hepatitis B virus. Here's how it happened:

1. **Recognition of the Virus**: When the hepatitis B virus entered Sarah's body, her immune system recognized it as a foreign invader. This is primarily done by white blood cells called macrophages, which engulf the virus and present its antigens (unique proteins on the surface of the virus) to other immune cells.

2. **Activation of Lymphocytes**: The antigens presented by the macrophages activate specific types of lymphocytes (another type of white blood cell) - B cells and T cells. B cells are responsible for producing antibodies, while T cells are responsible for killing infected cells and regulating the immune response.

3. **Production of Antibodies**: Once activated, B cells start producing antibodies specific to the hepatitis B virus. These antibodies bind to the antigens on the virus, marking them for destruction.

4. **Destruction of the Virus**: The marked viruses are then destroyed by other immune cells, such as cytotoxic T cells and natural killer cells.

5. **Memory Cells**: Some of the activated B and T cells become memory cells. These cells remain in the body long after the infection has cleared, ready to respond quickly and effectively if the same virus tries to infect the body again.

6. **Recovery**: As the immune system successfully destroys the hepatitis B virus, Sarah's symptoms start to clear up. Her liver begins to heal, and she recovers from the illness.

This is a simplified explanation of a very complex process, but it gives a general idea of how Sarah's third line of defence fought off the hepatitis B virus.

Question

Sarah's third line of defence, also known as the immune response, played a crucial role in fighting off the hepatitis B virus. Here's how it happened:

1. **Recognition of the Virus**: When the hepatitis B virus entered Sarah's body, her immune system recognized it as a foreign invader. This is primarily done by white blood cells called macrophages, which engulf the virus and present its antigens (unique proteins on the surface of the virus) to other immune cells.

2. **Activation of Lymphocytes**: The antigens presented by the macrophages activate specific types of lymphocytes (another type of white blood cell) - B cells and T cells. B cells are responsible for producing antibodies, while T cells are responsible for killing infected cells and regulating the immune response.

3. **Production of Antibodies**: Once activated, B cells start producing antibodies specific to the hepatitis B virus. These antibodies bind to the antigens on the virus, marking them for destruction.

4. **Destruction of the Virus**: The marked viruses are then destroyed by other immune cells, such as cytotoxic T cells and natural killer cells.

5. **Memory Cells**: Some of the activated B and T cells become memory cells. These cells remain in the body long after the infection has cleared, ready to respond quickly and effectively if the same virus tries to infect the body again.

6. **Recovery**: As the immune system successfully destroys the hepatitis B virus, Sarah's symptoms start to clear up. Her liver begins to heal, and she recovers from the illness.

This is a simplified explanation of a very complex process, but it gives a general idea of how Sarah's third line of defence fought off the hepatitis B virus.

Knowee AI · Accepted Answer