What is Immune Response? Primary Immune Response The immune response can be divided into four distinct phases when the body encounters an antigen for the first time. These phases include the lag phase, exponential phase, plateau phase, and decline phase. Each phase plays a crucial role in the overall immune response. In addition to the … Read more
What is The Rh blood group? Nomenclature of Rh blood group Antigens of the Rh blood group The Rh blood group system consists of 49 antigens, with the most significant ones being D, C, E, c, and e. The specificity of most Rh antigens is determined by the sequence of amino acids in the proteins. … Read more
What is Autoimmunity? General Features Of Immunologic Tolerance Autoimmunity, encompassing more than 80 different conditions, affects approximately 5% of the population. While each autoimmune disease may have unique characteristics, there are several common features shared among them: Autoimmune diseases can be classified into two broad categories based on the nature of the targeted self-antigens: organ-specific … Read more
What is Type I Hypersensitivity Reaction? Definition of Type I Hypersensitivity Reaction? Type I hypersensitivity reaction, also known as immediate hypersensitivity, is an exaggerated immune response triggered by the re-exposure to a specific allergen. It involves the rapid release of inflammatory mediators from mast cells and basophils sensitized with IgE antibodies. This type of reaction … Read more
What is Type II Hypersensitivity? Definition of Type II Hypersensitivity Type II hypersensitivity is an immune response characterized by the destruction of healthy cells mediated by antibodies, specifically IgG or IgM, targeting antigens on the surface of host cells. This antibody-mediated reaction can lead to cell lysis, tissue damage, or loss of function. Mechanism of … Read more
What is Type III Hypersensitivity? Definition of Type III Hypersensitivity Type III hypersensitivity is an allergic reaction characterized by the accumulation of immune complexes (antigen-antibody complexes) in tissues, leading to inflammation and tissue damage. Types of Type III hypersensitivity reaction Type III hypersensitivity reactions can be categorized into localized and generalized reactions. The manifestation of … Read more
What is Class I MHC (Major Histocompatibility Complex) molecules? Cellular Distribution of Major Histocompatibility Complex I (MHC I) Major Histocompatibility Complex I (MHC I) Structure The majority of nucleated cells have an assortment of MHC class I proteins. The peptides bound by these MHC class I molecules are typically endogenous, or derived from the breakdown … Read more
What is Type IV or Delayed-Type Hypersensitivity (DTH)? Definition of Type IV or Delayed-Type Hypersensitivity (DTH) Type IV or Delayed-Type Hypersensitivity (DTH) is an immune response mediated by T cells rather than antibodies, characterized by a delayed onset (usually 24-72 hours) after exposure to an antigen. It involves the interaction of CD4+ T cells, monocytes, … Read more
What is Major Histocompatibility Complex II (MHC II molecules)? Cellular Distribution of Major Histocompatibility Complex II (MHC II molecules) Structure of Major Histocompatibility Complex II (MHC II molecules) As stated previously, MHC class II molecules are nearly exclusively located on APCs. The peptides bound by MHC class II are produced from the breakdown of proteins … Read more
What is Lymph Nodes? Definition of Lymph Nodes Lymph nodes are small organs in the lymphatic system that filter lymph and play a critical role in the body’s immune response. Location of Lymph Nodes Size of Lymph Nodes The size of lymph nodes can vary depending on their location within the body. Here are some general guidelines … Read more
