Origins And Roles Of B Cells And T Cell

The immune system is made up of several types of cells that work together to fight infections. Lymph cells (called lymphocytes) are the main type of cell in the adaptive immune system. There are 2 types of lymph cells: T cells and B cells. When B cells respond to an infection, they change into plasma cells. The plasma cells are found mainly in the bone marrow—the soft, inner part of some bones. The plasma cells

contaminated water or food
17. For each pathway listed in question #16, explain the relationship of the mode of transmission to the virulence of the invader.

The immune system depends on the body’s structures to help it function. For instance, the skin acts as the “body’s first line of defense.” If a pathogen finds a breach in the skin barrier, it is the circulatory system that must now signal the immune system of the invader. Shortly after, white blood cells will be notified of the infection and will target and destroy the pathogen.

51) What activity does cell 1 undertake to contribute to the body's defense against injury and infection? phagocytosis of foreign materials

One defence mechanism of the human body is that when a person gets ill or is infected the person will get a fever, this is a method of notifying the person. This is a bodily defence mechanism produced by the immune system, its main purpose is to make it difficult for the virus to multiply prepare for the virus. The body’s pH level will also change to make it less optimal for the virus. The immune system’s mechanism will change depending on the body’s condition. If the body gets cut the immune system will causes inflammation, this will cause red blood cells to come to the

a. This function is mediated by T cells and B cells (memory cells) in our body via adaptive immunity. The adaptive immune system evolved in early vertebrates and allows for a stronger immune response as well as immunological memory, where each pathogen is “remembered” by a signature antigen. The adaptive immune response is antigen-specific and requires the recognition of specific “non-self” antigens during a process called antigen presentation. Antigen specificity allows for the generation of responses that are tailored to specific pathogens or pathogen-infected cells. The ability to mount these tailored responses is maintained in the body by memory cells. Should a pathogen infect the body more than once, these specific memory cells are used to quickly eliminate it. So basically killer T cells will identify antigens present on foreign cells. These antigens are not found in any of the cells inside our body. Therefore, T cells will identify them and kill them.

Overwhelming, deleterious host immune response to an infection due to release of chemicals to fight the infection 2• 1

B-cells develop from pluripotent hematopoietic stem cells, which give rise to lymphoid progenitor cells in the bone marrow. These stem cells have become Pro-B cells when they have begun to express B-cell marker proteins such as CD34 and rearrange the genes that code for the

The organs that make up the lymphatic and immune system are the tonsils, spleen, thymus gland, lymph nodes, and lymphatic vessels. White blood cells (leukocytes), red blood cells (erythrocytes), plasma, and platelets (thrombocytes) make up the blood. Lymphocytes are leukocytes (white blood cells) that help the body fight off diseases. Two types of lymphocytes are B cells and T cells. Lymphocytes recognize antigens, or foreign substances/matter, in the body. Lymphocytes are a classification of agranulocytes, or cells (-cytes) without (a-) granules (granul/o) in the cytoplasm. B cells are created from stem cells, which are located in the bone marrow. B cells respond to antigens by becoming plasma cells. These plasma cells then create antibodies. Memory B cells produce a stronger response with the next exposure to the antigen. B cells fight off infection and bacteria while T cells defend against viruses and cancer cells. A hormone created by the thymus gland called thymosin changes lymphocytes into T cells. The thymus gland is active when you are a child and slowly shrinks, as you get older. T cells bind to the antigens on the cells and directly attack them. T cells secrete lymphokines that increase T cell production and directly kill cells with antigens. There are three types of T cells: cytotoxic T cells, helper T cells, and memory T cells.

The immune system utilizes enzymes to clean up debris as well as fight foreign living pathogens. One immune cell type engulfs microbes and debris and injects one or more of its “living enzyme packets” to destroy them. Once an immune cell’s enzymes become depleted, it dies a normal death.

The skin is the body's first line of defense it acts as a physical barrier and when there are breaks in the barrier, such as cuts the body reacts to produce blood clots and a mesh work of fibrous tissue. The opening is blocked, which prevents germs or pathogens that can cause disease, from entering the body. One important defensive mechanism involving blood is clotting. These pathogens may breach this first line of defense and enter the body. Some white blood cells called phagocytes, move out of the blood and to the infected areas. They surround the invading micro-organisms, killing and removing them from the body before they can cause disease. If more dangerous, specific pathogens enter, then an immune response is activated. Another kind of

Physical barriers and the Immune system defend the body against organisms that can cause infection (Tunkel, 2015). The first line of defense is the physical and chemical barriers. Some barriers include the skin, and urine flow. The skin being a primary barrier is

Normally the body is protected by the immune system. When the immune system detects an unwelcome visitor such as fungi, bacteria and or viruses

If a pathogen breaches barriers: innate immune response result into an immediate effect of non- specific response. All Innate immune systems derived from plants and animals, when a pathogen evades the innate response, a third layer of protection is possessed by vertebrates in which activation of adaptive immune system takes place. The immune system response adopts itself within an infection and pathogen recognition is improved. As a result of the improved response, its then retains itself when the pathogen is eliminated in form of an immunological memory and allows the adaptive immune system to mount faster and stronger when pathogen is encountered each time.

For the immune system to able to keep us healthy it needs to be able to recognise what is a danger to our body and therefore needs to be removed, and what is safe. Proteins are used to do this. Pathogens have proteins on their surface called antigens, which activate the immune system. Our own cells also have surface proteins which the immune system recognises as part of the body and therefore doesn’t attack. (1)