The Immune System
1. What Is The Human Immune System Comprised Of?The human immune system is comprised of, white blood cells (lymphocytes), thymus, spleen, lymph nodes, lymph vessels.
-Cells: Lymphocytes or White Blood Cells T cells and B cells White blood cells are called lymphocytes, they originate in the bone narrow but immigrate to parts of the lymphatic system (lymph nodes, spleen, and thymus). The two main lymphatic cells are the T cells and B cells. The lymphatic system has a transportation system called lymph vessels for storage of lymphocyte cells. The lymphatic system kicks out dead cells and invading organism like bacteria. T cells: t cells come in two different types, helper and killer cells. They are named t cells after the thymus. T cells are produced in the bone marrow and later they move to the thymus were they mature. B cells: b cells search antigens, when it finds one it connects to it, and inside the B cell a triggering signal is set off now, B cells need protein to become fully activated. Proteins are carried by T cells. During this process the B cell starts to make clones of itself. Two new cell types are created after this process, plasma cells and b memory cells. -Thymus The thymus is located between your lungs and behind your sternum, the i were t lymphocytes develop. The T stands for thymus to reflect this origin. In young people and teenagers this organ is active, while the person is older the organ becomes less active. -Spleen The spleen is a lymphatic organ that plays a fundamental role in protecting the body from invading pathogens. Its the largest blood filter. It releases an immediate innate reaction to microbial penetration. It also recognizes particular antigens. -Lymph Nodes And Lymph Vessels Lymph Nodes: Lymph nodes are garrisons of a lot of immunity cells (including B and T cells). They act as traps for foreign and help to make the immune system function.
Lymph Vessels: Lymph vessels are reservoirs for plasma and other substances. Without lymph vessels, lymph can not be effectively drained and, edema is the result. |
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2. What Are Pathogens?
A pathogen is an infectious agent that causes disease to its host. Most pathogens are microbes, the most common are bacteria or viruses which are capable of causing disease. Fungi and protozoans are also considered pathogens. Not all microbes are harmful, pathogens refer just to those who cause disease.
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Types of Pathogens:
Prions: infectious protein that causes the degeneration of brain tissue in mammals. A form of proteins that have undergone alteration form their normal shape to an abnormal shape, however, the chemical composition of the protein remains unaltered.
Viruses: ultramicroscopic infectious agent that replicates itself only within cells of living hosts; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein).
Bacteria: prokaryotic cells that are present in the soil, air, water and in many humans body parts, such as the skin.
Fungi: eukaryotic organisms, most composed of a system of microscopic tubular filaments or threads which branch to form a mycelium structure. Fungi are saprophytes (live on dead plant and animal materials).
Macro Parasites: Multicellular organisms that are visible to the naked eye, also called parasites.
Protozoa: Unicellular organisms that are usually categorized according to their locomotion.
Prions: infectious protein that causes the degeneration of brain tissue in mammals. A form of proteins that have undergone alteration form their normal shape to an abnormal shape, however, the chemical composition of the protein remains unaltered.
Viruses: ultramicroscopic infectious agent that replicates itself only within cells of living hosts; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein).
Bacteria: prokaryotic cells that are present in the soil, air, water and in many humans body parts, such as the skin.
Fungi: eukaryotic organisms, most composed of a system of microscopic tubular filaments or threads which branch to form a mycelium structure. Fungi are saprophytes (live on dead plant and animal materials).
Macro Parasites: Multicellular organisms that are visible to the naked eye, also called parasites.
Protozoa: Unicellular organisms that are usually categorized according to their locomotion.
3. How Do Bacteria And Viruses Infect Cells?
When the bacteria enters the host in finds a cell, it will attach to it and introduce its DNA leaving the cell with its DNA, when the cell makes copies of what it thinks its DNA, is producing more bacterial DNA and will be destroying cells until medicine is proportioned.
Viruses are in our environment just waiting to host a cell. They can enter us through the nose, mouth or brakes in the skin. The first thing they will do after entering to us is to find a cell to infect.
Regardless of the type of host cell, all viruses follow the same basic steps in what is known as the lytic cycle:
Viruses are in our environment just waiting to host a cell. They can enter us through the nose, mouth or brakes in the skin. The first thing they will do after entering to us is to find a cell to infect.
Regardless of the type of host cell, all viruses follow the same basic steps in what is known as the lytic cycle:
- A virus particle attaches to a host cell.
- The particle releases its DNA into the host cell.
- The injected genetic material recruits the host cell's enzymes.
- The enzymes make parts for more new virus particles.
- The new particles assemble the parts into new viruses.
- The new particles break free from the host cell.
4. How Is A bActerial and A vIRAL INFECTION Treated?Bacterial Infection:
The body reacts to the disease by increasing local blood (inflammation) and sending cells of the immune system to attack and destroy bacteria. Antibodies attach to the bacteria and help in their destruction. Serious infections can be treated with antibiotics, which work by disrupting the bacterium’s metabolic processes, although antibiotic-resistant strains are starting to emerge. Immunisation is available to prevent many important bacterial diseases such as Hemophilus influenza Type b (Hib) and tetanus. |
Viral Infection:
Antiviral drugs are used against viral infection, because viruses are simple so they use their host cells to make their activities for them. Antibiotics are useless against them. Antiviral drugs are currently only effective against a few viral diseases, such as influenza, herpes, hepatitis B and C and HIV – but research is ongoing. A naturally occurring protein, called interferon (which the body produces to help fight viral infections), can now be produced in the laboratory and is used to treat hepatitis C infections. |
5. Discoveries that led to the understanding of the Immune System Today?
The earliest known reference to the immune system was during the plague of Athens in 430 BC. Thucydides saw that people who had recovered from a previous disease could not contract the same illness a second time. In the 18th century, Pierre-Louis Moreau de Maupertuis made experiments with scorpion venom and observed that certain dogs and mice were immune to this venom. This and other observations of acquired immunity were later exploited by Louis Pasteur in his development of vaccination and his proposed germ theory of disease. Pasteur's theory was in direct opposition to contemporary theories of disease. It was not until Robert Koch's 1891 proofs, for which he was awarded a Nobel Prize in 1905, that microorganisms were confirmed as the cause of infectious disease. Viruses were confirmed as human pathogens in 1901.
6. How Does The Immune System Protect A Person? WHAT ARE IMMUNE SYSTEM DEFENSES?
The immune system protects against disease with steps called the immune response. The responsible cells for the body reaction to a disease are the white blood cells or leukocytes. Leukocytes are circulating around the body on the lymphatic vessel and blood vessels allowing to seek out and protect the body from any disease that is present. The first types of Leukocytes called phagocytes are responsible for attacking and destroying the virus or bacteria. The second type: lymphocytes, recognize and remember invading virus and bacteria and help coordinate the body’s response to these organisms. Our immune system protects us from disease by first detecting and recognizing a foreign body or antigen. The B lymphocytes produce antibodies, which are special proteins designed to lock onto the antigen and neutralize it. Once the immune system has identified and destroyed an antigen the antibodies remain in the blood stream and protect the body against further invasion. This is how we become immune to disease.
7. Common Diseases
The immune system common diseases are:
1. Asthma is a chronic lung disorder that is caused when there is inflammation of the air passages. Allergens and even physical exertion can cause asthmatic symptoms such as wheezing, shortness of breath, coughing, and chest tightness.
2. Another one of the most prevalent of immune system diseases and disorders is HIV/AIDS. HIV/AIDS is a major breakdown in the immune system that leads to death. There is no known cure to HIV/AIDS.
3. Food, drug, and insect allergies are a result of the immune system becoming aggravated by a normally harmless substance. There are countless allergens such as pollen, mold, latex, food items like peanut butter and eggs, and prescription drugs like penicillin. Immune system diseases and disorders such as allergies have many allergic responses.
4. Another of the most common symptoms of immune system failure are skin allergies. Skin allergies are very similar to other allergies in which the immune system becomes aggravated by seemingly common substances. Skin allergies manifest themselves by itchy skin, redness, and lesions.
5. Repeated sickness/illness is also one of the most common immune system diseases and disorders. Immune system vitamins and minerals like antioxidants can help the immune system defend against sickness.
1. Asthma is a chronic lung disorder that is caused when there is inflammation of the air passages. Allergens and even physical exertion can cause asthmatic symptoms such as wheezing, shortness of breath, coughing, and chest tightness.
2. Another one of the most prevalent of immune system diseases and disorders is HIV/AIDS. HIV/AIDS is a major breakdown in the immune system that leads to death. There is no known cure to HIV/AIDS.
3. Food, drug, and insect allergies are a result of the immune system becoming aggravated by a normally harmless substance. There are countless allergens such as pollen, mold, latex, food items like peanut butter and eggs, and prescription drugs like penicillin. Immune system diseases and disorders such as allergies have many allergic responses.
4. Another of the most common symptoms of immune system failure are skin allergies. Skin allergies are very similar to other allergies in which the immune system becomes aggravated by seemingly common substances. Skin allergies manifest themselves by itchy skin, redness, and lesions.
5. Repeated sickness/illness is also one of the most common immune system diseases and disorders. Immune system vitamins and minerals like antioxidants can help the immune system defend against sickness.
8. Difference Humans And Animals
All vertebrates (including humans) have an immune system that is structured basically the same way. Most other multicellular organisms have an immune system, with a simpler variant. Comparing both systems are like comparing planes, some planes are bigger than other, but they make the same purpose. Similarly, each species creates immune cells and molecules that function in basically the same way, but have variations here and there that make them incompatible with one another.
When it comes to animal testing, the immune system of mammals is for most purposes, functionally identical, which is why it is often possible to model the immune response to human diseases in rats or monkeys, for instance. However, the tiny differences in cell receptors or markers means that there are still differences in responses which can actually turn out to be quite dramatic. That's why all medications or vaccines or whatever have to eventually be tested in humans, regardless of how wonderfully they work in lab animals.
When it comes to animal testing, the immune system of mammals is for most purposes, functionally identical, which is why it is often possible to model the immune response to human diseases in rats or monkeys, for instance. However, the tiny differences in cell receptors or markers means that there are still differences in responses which can actually turn out to be quite dramatic. That's why all medications or vaccines or whatever have to eventually be tested in humans, regardless of how wonderfully they work in lab animals.