What is the primary immune system?

Answer 1

The immune response occurring on the first exposure to a foreign material in the body.

This reaction is by both the innate and acquired immune system, the innate acting first (non specific) and the acquired developing to produce antibodies and T killer cells specific to the invading microorganism.

The innate immune system (that which is always active and is non specific) primarily involves neutrophils, a type of white blood cell specialised to release many different chemicals for signalling and is able to phagocytose (engulf and digest) foreign materials such as bacteria. On doing this is dies. At a site of infection under microscopy you will see lots of dead neutrophils, they are the main component of pus. Another of the primary responses is swelling, caused by vasodilation and increased permeability of blood vessels in the area/site of the tissue and cell damage.
When undergoing an innate response it is (unless caused by an autoimmune disease) a response to cell damage. When cells are damaged (such as by trauma, virus or bacterium) they release arachidonic acid, which is used by neutrophils when present to create substances to help vasodilate and increase the permeability of venule and capillary walls near the area. This is acute inflammation and initial neutrophil response. Coagulation factors and increased platelet synthesis also occurs (responsible for sealing off bleeding and creating a barrier if necessary to temporarily replace skin lost at the site of the wound).

The acquired response is a specific response based on the invading material. If a bacterium or virus is present and detected, macrophages will engulf and digest it, and present antigens/epitopes of the invader on their surface and 'alert' the B and T lymphocytes using these. The B and T cells reside in lymph nodes. The B-lymphocytes with the correct paratopes (receptors) will differentiate to memory cells and generate antibodies specific to shapes on its surface (antigens/epitopes) which will agglutinate and help destroy the invading cells or organisms.The T killer cells will destroy affected cells, T helper cells will assist B cells in multiplying and differentiating to plasma cells, that can then produce the specific antibodies.

The secondary response involves mainly memory cells, this is the response that occurs on the second entrance of a microorganism or virus that has been encountered before and dealt with by the primary response. I mentioned that B cells differentiate to plasma cells when triggered by the macrophages presenting the foreign epitopes (recognition sites). Well they also differentiate into long lived memory cells. Memory cells can differentiate straight into plasma cells in the secondary response and produce antibodies straight away without having to wait for the macrophages to present and B cells to multiply and so on. This makes the secondary response faster, more efficient, more specific and produce more antibodies in total. This is the theory of vaccinations, you will develop memory cells specific to the injected material so that if you contract the microorganism or virus in a real situation you will be able to kill it off before it accumulates to a serious level.

See a graph for a visual explanation. It takes less time and has more antibodies generated during the secondary response that the first.

Answer 2

The immune response occurring on the first exposure to a foreign material in the body.

This reaction is by both the innate and acquired immune system, the innate acting first (non specific) and the acquired developing to produce antibodies and T killer cells specific to the invading microorganism.

The innate immune system (that which is always active and is non specific) primarily involves neutrophils, a type of white blood cell specialised to release many different chemicals for signalling and is able to phagocytose (engulf and digest) foreign materials such as bacteria. On doing this is dies. At a site of infection under microscopy you will see lots of dead neutrophils, they are the main component of pus. Another of the primary responses is swelling, caused by vasodilation and increased permeability of blood vessels in the area/site of the tissue and cell damage.
When undergoing an innate response it is (unless caused by an autoimmune disease) a response to cell damage. When cells are damaged (such as by trauma, virus or bacterium) they release arachidonic acid, which is used by neutrophils when present to create substances to help vasodilate and increase the permeability of venule and capillary walls near the area. This is acute inflammation and initial neutrophil response. Coagulation factors and increased platelet synthesis also occurs (responsible for sealing off bleeding and creating a barrier if necessary to temporarily replace skin lost at the site of the wound).

The acquired response is a specific response based on the invading material. If a bacterium or virus is present and detected, macrophages will engulf and digest it, and present antigens/epitopes of the invader on their surface and 'alert' the B and T lymphocytes using these. The B and T cells reside in lymph nodes. The B-lymphocytes with the correct paratopes (receptors) will differentiate to memory cells and generate antibodies specific to shapes on its surface (antigens/epitopes) which will agglutinate and help destroy the invading cells or organisms.The T killer cells will destroy affected cells, T helper cells will assist B cells in multiplying and differentiating to plasma cells, that can then produce the specific antibodies.

The secondary response involves mainly memory cells, this is the response that occurs on the second entrance of a microorganism or virus that has been encountered before and dealt with by the primary response. I mentioned that B cells differentiate to plasma cells when triggered by the macrophages presenting the foreign epitopes (recognition sites). Well they also differentiate into long lived memory cells. Memory cells can differentiate straight into plasma cells in the secondary response and produce antibodies straight away without having to wait for the macrophages to present and B cells to multiply and so on. This makes the secondary response faster, more efficient, more specific and produce more antibodies in total. This is the theory of vaccinations, you will develop memory cells specific to the injected material so that if you contract the microorganism or virus in a real situation you will be able to kill it off before it accumulates to a serious level.

See a graph for a visual explanation. It takes less time and has more antibodies generated during the secondary response that the first.

Answer 3

The primary immune system is also called innate immunityor auxiliary immunity because it is unspecific and present in everyone. These include physical and chemical barriers that protect the body from many different microscopic organisms.

--Skin (and hair) acts as a large physical barrier. The skin produces chemicals that make the surface harder for bacteria to live on. It is relatively salty, has layers that constantly flake away, and even has some antibacterial chemicals such as lysozyme.

--Mucous lining the internal cavities, such as the respiratory tract, helps trap microbes. Cells with little beating hairs called cilia also line many body cavities and sweep away the mucous-trapped microbes and debris.

--Tears flush across the eyes with every blink; they also contain the enzyme lysozyme.

--Saliva helps protect the mouth and throat. It physically washes bacteria away. (When you sleep you produce less saliva, which is why people have morning breath.)

-Digestive acids and enzymes in the stomach and small intestine destroy most microbes.

-- Microphages are white blood cells that will engulf (eat) any invader they bumb into. They roll along the blood stream and can be called to a certain area through chemical signals. Inflammation is when damaged or distressed cells release the chemical histamine. The histamine causes blood vessels to dilate (expand and allow more blood flow) and attract white blood cells.

--Antibodies are large molecules in the blood that attach to specific proteins on the surface of invaders. They are usually developed immunity but there are some that people are born with without yet being exposed to the antigen that they attack.

--Natural flora is a population of helpful bacteria that often times will suppress the growth and repopulation of harmful bacteria. They can be found on the skin, genitourinary tract, mouth, throat, and intestines.

*You are not born with these microbes; they must be obtained from the environment. For this reason they are not always counted as part of the innate immune system.

*The primary immune system should not be confused with the primary immune response. That would be specific to when the body is first exposed to certain protein markings (antigens) on the invading microbe. They body must learn to identify and destroy the specific invaders.

Answer 4

The first injection of an antigen into an animal induces the transformation of only a small number of small lymphocytes into lymphocytes (plasma cells). Circulating antibodies 0 the antigen appear after a time interval, called the latent period, which varies from I to 30 days (average fifth to the fourteenth day) us when bovine serum albumin is injected into a rabbit, antibodies an be detected in the rabbit's serum after a few days. This type of response in known as the primary response, and occurs when an animal has not previously come into immunological contact with an antigen.

The circulating antibody level increases exponentially to a peak during the next 5 to 6 days and then declines. The antibody produced during the primary response is mainly 19M, although IgG antibodies appear later. A second injection of antigen given during the decline period, or after the antibody from the primary response disappears, brings about a more vigorous response, called the secondary response.

More cells participate in this response than the in the primary response. The secondary response is more rapid and produces a greater amount of antibody. Moreover, the antibody concentration remains high for a much longer period. The main antibody produced during the secondary response is IgG. The secondary response is due to the activity of the B-lymphocytes (memory cells) stimulated during the primary response. The increased secondary response indicates the presence of immunological memory.

Answer 5

The secondary response comes subsequently to the primary immune response and it is also more rapid and effective.