Understanding Immune Defense Mechanisms: Specific and Nonspecific
Nonspecific Defense Mechanisms
Nonspecific Defense Mechanisms:
- Skin (mechanical barrier)
- Mucous secretions
- Microflora
Specific Defense Mechanisms
Specific Defense Mechanisms:
The cells involved in the immune process are leukocytes, found in the blood or tissue.
- Granulocytes: Leukocytes with cytoplasm granules loaded with substances that may be released.
- Agranulocytes: Cells that are absorbing or danticossos.
Nonspecific Immune Response
The nonspecific immune response depends on the type of infecting agents. It is immediate, urgent, and requires no prior sensitization.
Acute inflammation is a response to the presence of foreign agents in the organism.
After stimulation, the affected cells release substances called inflammation mediators.
This produces vasodilation and increased capillary permeability, which facilitates diapedesis.
The absorbing cells reach the site of infection, and phagocytosis of infectious agents occurs. The primary absorbing cells are neutrophils and macrophages.
Complement System
The complement system is a system of serum proteins that carry out three important functions:
- Acts as a mediator of inflammation.
- Favors phagocytosis.
- Raises cell lysis by membrane rupture.
Components activate early in contact with the surface of foreign cells, which can occur through:
- The presence or union of danticossos with the polysaccharides present in bacteria.
Late components join activated primarencs components, and the way meets datac membrane protein complex called.
Specific Humoral Immune Response
(Which is done using specific antibodies)
Antibodies
Antibodies are glycoproteins that are synthesized in response to a specific antigen.
Antigens
Antigens are molecules that provoke an immune response and interact with a T cell receptor.
Types of Antibodies
There are 5 types of danticossos:
- Immunoglobulin G (IgG): The most abundant in the blood. Can cross the placental barrier and immunize the fetus against antigens.
- Immunoglobulin M (IgM): Effectively activates complement and is capable of agglutinating, neutralizing, and precipitating soluble antigens.
- Immunoglobulin A (IgA): Occurs in the blood or secretions, such as mucous.
- Immunoglobulin E (IgE): Appears in the blood and extracellular fluid, causing the expulsion of contents from their granules.
- Immunoglobulin D (IgD): Acts as an antigen receptor. Joins dantígens recognition and antibody production daltres.
Macrophages and Lymphocytes
Macrophages and other cells are capable of processing and presenting Lantig inespecificament cells in T. However the cells are more efficient than present Lantig B lymphocytes. Aquets have the surface antigen receptor, which in suneixen Lantig. Then this will be recognized by a lymphocyte antigen with which sunirà Th. After the union, the Th lymphocyte interleukins segregarà mission which will make the B cells proliferate and create clones of activated B cells that are differentiated into two types:
- Plasma cells: Short-lived but sagreguen danticossos large quantities.
- B cell memory: Become long-lived plasma cells secreting specific danticossos if there is a new exhibition at Nha Lantig that induced the formation.
Specific Immune Responses
T lymphocytes are the cellular elements responsible. Because it is carried out lactivació Th lymphocytes are necessary two signals:
- The 1st contact is made between the compliance of antigen presenting cell and Lantig of lymphocyte antigen receptor.
- The 2nd type of signal was by using chemical or interleukin protein contact between the cell and presented Lantig of lymphocyte membrane proteins.
Vaccination
Vaccination is an artificial example dimmunitat active, ie lorganisme triggers a specific immune response following the introduction of killed or attenuated microorganisms. It preventive measure dune dune disease.
The changes in hereditary material involving changes in protein vaccination makes creating dunes memory cells that produce antibodies specific to an antigen (protein) to determine whether changes Lantig (albeit only a small part) of the vaccine disappears lacció