Found 30 Articles for Immunology

Introduction Immunology is basically the study of immune system of an organism which protects the organism from physical, chemical and biological invasions. Immunity: Immunity is our body’s protective mechanism against pathogens which includes the disease inducing micro-organisms like bacteria, virus, fungi, protozoa etc. We do need immunity as our body constantly attacked by several pathogens in a day to day life. How Does Our Immune System Works? Immune system includes a complex set of tissues, cells and specialized molecules which protects our body from any foreign particles like microorganisms that enter our body. For effective functioning of our ... Read More

Basics of Immunology: Immune System Immunology is the study of an immune system which provides resistance to disease caused by the micro-organisms and their products like toxins. This resistance is termed as immunity and this also provides resistance even to cancer cells. Immune system mainly works on following principle strategies − It prevents the pathogen entry into the body Eliminates the invaded pathogens by involving different immune cells. Preventing the attack on the host’s own or self-cells. Stored memory of previously invaded pathogens by T and B cells. Should able to limit its immune response once the pathogen is ... Read More

Introduction Memory cells are long-lived immune cells capable of recognizing foreign particles that they had encountered previously. Memory cells capture the antigen or components of foreign antigen that invades our body and provides protection against them very fast when compared to the initial attack. Antigen exposure and its immune response usually 2 types Initial Exposure – Primary immune response, here the memory does not take part in providing an immune response. Secondary Exposure (when a similar kind or same antigen attacks the immune system) – Here memory cells start initiating the secondary immune response Here the time ... Read More

Introduction Natural killer cells or NK cells are a type of lymphocytes derived from lymphoid stem cells. These are the important components of innate immunity and eliminate pathogens by releasing some chemicals called cytokines which are similar to the ones produced by the T cells. Natural killer cells are indeed the lethal weapons of the immune system. Properties of NK Cells A few properties of NK cells are discussed below − NK cells constitute only 5-10% of the lymphocytes. These NK cells are large granular lymphocytes that contain a large round nucleus when compared to RBC. NK cells ... Read More

Introduction Lymphocytes are the type of white blood cells in the immune system. These are the main type of cells found in the lymph of a lymphatic system. These constitute about 18-42% of the circulating leukocytes present in the lymph. Usually, lymph contains waste products from the tissues, pathogens from the infected tissues, and also some proteins. Lymphocytes are mainly produced in the bone marrow through mitosis. Some of the cells remain in the bone marrow where as some lymphocytes move to the thymus, a primary lymphoid organ where its maturation occurs. Upon maturation, these cells move to the secondary ... Read More

What is Lymphatic System and How Does it, Work? Within the human body, there is a system that works as a drainage network helping to keep the fluids balanced while also helping to fight against infections. This network is called the lymphatic system which works with the circulatory system. The lymphatic system is mainly involved in the removal of excess fluid from the body tissues and returning it to the bloodstream. Hence the lymphatic system is a subsystem for the both circulatory and immune systems. Lymphatics are usually present all over the body except the areas like CNS, bone, teeth, ... Read More

Lymph Nodes in Relation to an Immune System Lymph nodes are the secondary lymphoid organs of the lymphatic system. Usually the term lymphoid belongs to immune system-related functions. The lymphatic system which is an extension of the circulatory system usually carries the lymph back to the bloodstream. This lymphatic system does not have any pump but the motion of the lymph mainly occurs due to muscular movements. As the lymphatic system dumps back the lymph into the circulatory system it is said to be a backup drainage system to prevent excess fluid retention in the tissues which can lead to ... Read More

What is an Infection? In clinical microbiology, to have knowledge of the basics one should learn to know a few very important terms like infection, immunity, disease, etc. The main terms infection and immunity are the effects which are resulted from an interaction between the host and a micro-organism. Infection occurs when organisms find their way into the host body and grow in numbers beyond the level that the immune system is able to defend against. So infection usually occurs when the natural host’s defenses like cilia, intact skin, gastric acid, and the immune system are compromised or overpowered. Infections ... Read More

Introduction Normally our immune system shows a response towards the foreign antigen and does not act against self-antigens. This phenomenon is known as self-tolerance. It refers to the lack of responsiveness to the individual’s self-antigens. Hence tolerance is antigen-specific. Immune Response Immune tolerance or immunological tolerance is the state of unresponsiveness of the immune system to the substances or tissues that are capable to induce an immune response. It differs from the conventional methods of immune-mediated elimination of foreign antigens. Due to random genetic recombinations, immune cells genetically express receptors for the specific self and foreign antigens in the ... Read More

Introduction Our immune system produces a nearly infinite number of lymphocytes and each of these expresses unique antigen-specific receptors on its cell membrane. These receptors are encoded by the random re-arrangement of pre-existing gene segments. Antigen-specific receptors are usually generated in the early development stages of lymphocytes which is prior to the encounter with the specific antigens. These antigen-specific receptors on the T-cells are called TCR and on B cells called BCR. These lymphocyte receptors when encounters a specific antigen, get stimulated and undergo proliferation to produce the clone of specific lymphocytes, and at last these get differentiated into effector ... Read More