Admin Table of Contents
Where does the antigen challenge occur?
The antigen challenge is the first encounter between an immunocompetent lymphocyte and an invading antigen. It usually takes place in the spleen or a lymph node, but may happen in any lymphoid tissue.
What is antigen effect?
According to the allosteric model, antigen by virtue of its chemical structure induces conformational changes distal to the combining site. These changes would in turn lead to changes in the molecule (receptor) which was activated by the antigen-antibody complex.
What is an antigen short answer?
An antigen is any substance that causes your immune system to produce antibodies against it. This means your immune system does not recognize the substance, and is trying to fight it off. An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen.
What is antigen determination?
The small area of chemical grouping on the antigen molecule that determines specific immune response and reacts specifically with antibody is called an antigenic determinant.
Why is phagocytosis not always successful?
Phagocytosis differs from other methods of endocytosis because it is very specific and depends on the cell being able to bind to the item it wants to engulf by way of cell surface receptors. Phagocytosis won’t happen unless the cell is in physical contact with the particle it wants to engulf.
What is immunocompetent patient?
Scientifically, to be immunocompetent simply means that the immune system is working properly and that the body is capable of mounting an appropriate immune response, when necessary.
What are 3 types of antigens?
There are three main types of antigen The three broad ways to define antigen include exogenous (foreign to the host immune system), endogenous (produced by intracellular bacteria and virus replicating inside a host cell), and autoantigens (produced by the host).
What are the 4 steps of phagocytosis?
The process of phagocytosis involves several phases: (i) detection of the particle to be ingested, (ii) activation of the internalization process, (iii) formation of a specialized vacuole called phagosome, and (iv) phagosome maturation.
What are the 5 stages of phagocytosis?
Terms in this set (5)
- Chemotaxis. – movement in response to chemical stimulation.
- Adherence. – attachment to a microbe.
- Ingestion. – engulfing pathogen with pseudopodia wrapping around pathogen.
- Digestion. – phagosome maturation.
- Elimination. – phagocytes eliminate remaining pieces of microbe via exocytosis.