What is the tissue macrophage system
The tissue macrophage system is a network of immune cells that play a crucial role in the defense against infections and in the maintenance of tissue homeostasis.
- The tissue macrophage system consists of macrophages and dendritic cells
- These cells are derived from monocytes and are found in various tissues
- They are involved in the phagocytosis of foreign particles and microorganisms
- They also play a role in the presentation of antigens to T cells
Describe the morphology and functions of lymphocytes and plasma cells
Lymphocytes are a type of white blood cell that plays a key role in the immune system.
- Lymphocytes are divided into two main types: B cells and T cells
- B cells are responsible for producing antibodies
- T cells are involved in cell-mediated immunity
- Plasma cells are mature B cells that produce large amounts of antibodies
- Lymphocytes have a large nucleus and a small amount of cytoplasm
- They are found in the blood, lymphoid organs, and lymphoid tissues
Explain the functions of spleen
The spleen is an organ that is located in the upper left region of the abdomen.
- The spleen filters the blood and removes old, damaged red blood cells
- It also stores red blood cells and platelets
- The spleen is involved in the immune response and produces antibodies
- It filters the lymph and removes pathogens and other foreign substances
- The spleen is also involved in the production of white blood cells
Discuss the formation and functions of lymph
Lymph is a clear fluid that is formed from the interstitial fluid.
- Lymph is formed when the interstitial fluid enters the lymphatic capillaries
- The lymphatic capillaries are blind-ended tubes that are found in the tissues
- The lymph is transported through the lymphatic vessels and eventually enters the bloodstream
- Lymph plays a crucial role in the immune response and helps to defend the body against infections
- It also helps to remove waste products and other foreign substances from the body
Define immunity
Immunity is the ability of the body to defend itself against infections and diseases.
- Immunity is mediated by the immune system, which consists of various cells, tissues, and organs
- The immune system recognizes and responds to pathogens, such as bacteria, viruses, and other foreign substances
- Immunity can be innate or adaptive
- Innate immunity is non-specific and provides immediate protection against infections
- Adaptive immunity is specific and provides long-term protection against infections
Explain different types of immunity
There are two main types of immunity: innate immunity and adaptive immunity.
- Innate immunity is non-specific and provides immediate protection against infections
- Adaptive immunity is specific and provides long-term protection against infections
- Active immunity is acquired through the production of antibodies
- Passive immunity is acquired through the transfer of antibodies from one person to another
- Cell-mediated immunity involves the activation of T cells
- Humoral immunity involves the production of antibodies by B cells
Discuss development of immune response
The development of an immune response involves several steps: step 1 → recognition of the pathogen by the immune system step 2 → activation of immune cells, such as macrophages and dendritic cells step 3 → presentation of antigens to T cells step 4 → activation of T cells and B cells step 5 → production of antibodies and activation of immune cells step 6 → elimination of the pathogen
Discuss autoimmunity and hypersensitivity
Autoimmunity occurs when the immune system mistakenly attacks the body's own cells and tissues.
- Autoimmunity can result in various diseases, such as rheumatoid arthritis and lupus
- Hypersensitivity is an exaggerated immune response that can result in tissue damage
- There are four types of hypersensitivity reactions: type I, type II, type III, and type IV
- Type I hypersensitivity reactions involve the release of histamine and other chemical mediators
- Type II hypersensitivity reactions involve the production of antibodies that bind to cell surface antigens
- Type III hypersensitivity reactions involve the formation of immune complexes
- Type IV hypersensitivity reactions involve the activation of T cells
Discuss immunodeficiency diseases
Immunodeficiency diseases occur when the immune system is impaired or deficient.
- Immunodeficiency diseases can be congenital or acquired
- Congenital immunodeficiency diseases are present at birth
- Acquired immunodeficiency diseases are acquired through infection or other factors
- Examples of immunodeficiency diseases include HIV/AIDS, severe combined immunodeficiency (SCID), and common variable immunodeficiency (CVID)
- Immunodeficiency diseases can increase the risk of infections and other diseases
- Treatment of immunodeficiency diseases depends on the underlying cause and may involve medications, bone marrow transplantation, or other therapies