B CELLS and T CELLS EXPLAINED!

Summary

This video explains the adaptive immune system's response to viral and bacterial infections, focusing on the roles of B cells and T cells. It covers two branches of immunity: innate and adaptive. The innate system is quick but nonspecific, while the adaptive system is highly specific, targeting particular pathogens. B cells produce antibodies that neutralize infections in body fluids, while T cells target and destroy infected cells. The video emphasizes the specificity of adaptive immunity, highlighting its effectiveness in combating infections but also its limitations in dealing with diverse pathogens.

Takeaways

• 😀 The immune system consists of two main branches: innate and adaptive immunity.
• 😀 The innate immune system provides a quick but non-specific response to infection.
• 😀 The adaptive immune system is more specific and effective, providing immunity against particular pathogens.
• 😀 B cells and T cells are the key players in the adaptive immune response.
• 😀 B cells provide humoral-mediated immunity by secreting antibodies that circulate in the body's fluids.
• 😀 T cells offer cell-mediated immunity by killing infected cells directly.
• 😀 B cells use antibodies to opsonize pathogens, marking them for destruction by phagocytic cells.
• 😀 T cells, specifically CD8 cytotoxic T cells, kill infected cells, halting viral replication.
• 😀 Both B cells and T cells must work together for a complete immune response.
• 😀 The adaptive immune response is highly specific, with antibodies and T cells targeting only certain pathogens.
• 😀 The specificity of the adaptive immune system, though powerful, limits its ability to respond to multiple pathogens at once.

Q & A

What are the two main branches of the immune system?

The two main branches of the immune system are the innate immune system and the adaptive immune system.

How does the innate immune system respond to infections?

The innate immune system is the immediate and quickest response to an infection, but it is not very specific and often does not contain the infection completely.

Why is the adaptive immune system necessary?

The adaptive immune system is necessary because it provides a more specific and effective response to infections that the innate immune system cannot handle alone.

What are the two types of immunity provided by the adaptive immune system?

The two types of immunity provided by the adaptive immune system are humoral-mediated immunity (by B cells) and cell-mediated immunity (by T cells).

How do B cells contribute to the adaptive immune response?

B cells contribute by secreting antibodies into the body’s fluids. These antibodies bind to pathogens such as bacteria and viruses, preventing them from spreading.

What is opsonization, and how does it work in the immune system?

Opsonization is the process where antibodies bind to pathogens, marking them for destruction by phagocytic cells, which are part of the innate immune system.

What is the role of T cells in the adaptive immune response?

T cells, particularly CD8 cytotoxic T cells, kill infected cells in the body to stop the replication of viruses and, in some cases, cancer cells.

What is the difference between humoral-mediated immunity and cell-mediated immunity?

Humoral-mediated immunity is provided by B cells and involves antibodies circulating in body fluids to neutralize pathogens, while cell-mediated immunity involves T cells killing infected or cancerous cells.

Why is specificity important in the adaptive immune response?

Specificity allows the immune system to target a particular pathogen. Each antibody or T cell receptor is specific to one pathogen, ensuring a focused and effective immune response.

What is the limitation of the adaptive immune system's specificity?

The limitation of specificity is that each antibody or T cell can only respond to one specific type of pathogen, meaning that multiple types of B cells and T cells are required to protect against a wide range of infections.