IMMUNOLOGY- Innate Immunity and Adaptive Immunity (FL-Immuno/01)

Summary

This video lecture provides an overview of immunology, focusing on immunity, immune responses, and the immune system. It explains the two types of immunity: innate (natural) immunity, which offers an immediate defense against a wide variety of pathogens, and acquired (adaptive) immunity, which is specific and adaptive, forming the third line of defense. The lecture also covers antigen recognition, the components involved in immune responses, and the consequences of immune system failure, including allergies, autoimmune diseases, and immunodeficiency diseases. It emphasizes the importance of understanding immune mechanisms in protecting against infections.

Takeaways

• 😀 Immunity is the body's ability to resist infections and diseases, derived from the Latin word 'immunis', meaning 'exempt'.
• 😀 The immune system is a network of cells, molecules, tissues, and organs that work together to defend against pathogens like bacteria, viruses, and fungi.
• 😀 An immune response is the coordinated reaction of the immune system to pathogens, involving recognition and defense strategies.
• 😀 Phagocytosis is a key immune response where cells like phagocytes ingest and neutralize pathogens.
• 😀 Immunology is the science that studies the immune system, its functions, and its response to infections or diseases.
• 😀 There are two main types of immunity: innate immunity (inborn) and acquired immunity (adaptive).
• 😀 Innate immunity is the first line of defense, present at birth, and provides rapid, non-specific defense against a broad range of pathogens.
• 😀 Acquired immunity is highly specific and develops after birth, with immunological memory that allows the immune system to respond more efficiently to repeated infections.
• 😀 Antigens are substances on the surface of pathogens that are recognized by the immune system as foreign.
• 😀 Failure of the immune system can lead to consequences such as allergies, autoimmune diseases, and immunodeficiency diseases like HIV/AIDS.

Q & A

What is the definition of immunity?

Immunity is the general ability of a host to resist infections or diseases. The term 'immunis' in Latin means exempt, which refers to being free from burden, specifically the protection from pathogens and diseases.

What is the immune system and how does it function?

The immune system is the collection of cells, molecules, tissues, and organs that work together within an organism to resist infections. It acts as a defense mechanism against pathogens, neutralizing or eradicating infections once established.

How is an immune response defined?

An immune response is the coordinated reaction of the host's immune system to a foreign agent or pathogen. It involves the recognition and defense strategies against invaders, such as pathogens, through processes like phagocytosis.

What is phagocytosis and how does it work?

Phagocytosis is the process where a cell, such as a phagocyte, recognizes a pathogen like bacteria, ingests it, and internalizes it. Once inside, the pathogen is killed in a separate compartment, a key aspect of the immune system's defense.

What are the two types of immunity?

There are two main types of immunity: innate immunity and acquired (or adaptive) immunity. Innate immunity is the body's first line of defense, while acquired immunity develops after birth and provides a more specific response.

What is the role of innate immunity?

Innate immunity is the first and second line of defense, providing physical and chemical barriers to prevent pathogens from entering the body. It is non-specific and responds quickly, but it does not have immunological memory of past encounters.

How does innate immunity recognize pathogens?

Innate immunity recognizes structural features shared by various microbes, such as lipopolysaccharides found in gram-negative bacteria. The immune system can detect these common features and mount a defense without needing to know the specific pathogen.

What is acquired immunity and how is it different from innate immunity?

Acquired immunity, also known as adaptive immunity, is a specific and slower response to pathogens that an individual acquires during life. Unlike innate immunity, acquired immunity has immunological memory, allowing it to respond more effectively upon subsequent encounters with the same pathogen.

What are the key components of acquired immunity?

The main components of acquired immunity include B lymphocytes (B cells), T lymphocytes (T cells), and antigen-presenting cells. These cells work together to recognize and eliminate specific pathogens.

What happens when the immune system fails?

When the immune system fails, it can lead to various conditions, such as allergies, autoimmune diseases, and immunodeficiency diseases. For example, allergies occur when the immune system overreacts to harmless substances, while autoimmune diseases like rheumatoid arthritis involve the immune system attacking the body’s own tissues.