https://padlet.com/kshah29_4/2142ab93lvvhjdvx Made with ♥ en-us 2022-05-25 15:22:55 UTC 2022-05-26 01:49:12 UTC hello@padlet.com kshah29_4 https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199557032 2022-05-25 15:25:50 UTC https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199557032 kshah29_4 https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199557317 Innate immunity is the body's generic response to any kind of pathogen. It is made up of external and chemical barriers, or the "first line of defense" against pathogens, and internal defenses, or the "second line of defense".]]> 2022-05-25 15:26:03 UTC https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199557317 kshah29_4 https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199557496 Adaptive immunity is the body's specific, evolving response to a particular pathogen. It occurs after exposure to a specific antigen. Adaptive immunity also includes memory cells, which remember a certain virus and help the body be prepared to attack it quicker and more effectively the next time it is encountered.]]> 2022-05-25 15:26:11 UTC https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199557496 kshah29_4 https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199754633 The body's first line of defense is physical barriers, such as skin and mucus membranes. Keratin in the skin prevents pathogens from entering the cells, and mucus membranes in openings to the body trap viruses and prevent them from moving deeper into the body. Other physical barriers the body possesses are hair and Cilla that trap and move pathogens.

The body also has generic chemical responses to invading pathogens. The surface of the skin is acidic, and mucus, saliva, and tears from the eyes contain enzymes that break down bacteria. The stomach is also an acidic environment that is harmful to pathogens in the digestive tract.

The microbiome of the body is also part of its innate immune system, fighting against disease-causing organisms and outcompeting them for the body's resources.]]> 2022-05-25 17:59:32 UTC https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199754633 kshah29_4 https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199754794 The innate immune system also contains internal defenses which activate when pathogens breach its physical barriers and enter the body. White blood cells identify foreign invaders and release cytokines, signaling a viral infection to other cells. 

Cytokines then trigger an inflammatory response, which induces redness, swelling, heat, and pain at the sight of a physical trauma to the body. White blood cells are then attracted to the inflamed areas. One early-arriving white blood cell is a neutrophil, which devours and digests pathogens. Macrophages, which also engulf and digest foreign invaders and clean up cell debris, soon follow. Cytokines also raise the body's temperature, causing a fever which increases the metabolic processes of cells, allowing them to heal faster, and inhibits pathogen growth.

The body can also employ NK (natural killer) cells, which kill cells in the body which are infected with viruses. They identify infected cells by their altered expression of MHC 1 molecules, which are proteins present on the surface of every cell that express the state of its internal environment. Infected cells express altered forms of MHC. An NK cell will induce programmed cell death, or apoptosis, in cells it identifies as infected. ]]> 2022-05-25 17:59:40 UTC https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199754794 kshah29_4 https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199755198 An example of passive adaptive immunity would be the antibodies one receives from an outside source. A naturally acquired example would be antibodies one receives as a fetus from their mother's placenta, and as a baby from their mother's breast milk.]]> 2022-05-25 18:00:00 UTC https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199755198 kshah29_4 https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199755351 One part of active adaptive immunity is the body's humoral immune response, which attacks pathogens in the blood and lymph. This response involves B cells, cells that mature in the bone marrow. When antigens are identified in the body, B cells release antibodies that bind to the antigen and mark it as something to be attacked. Antibodies also neutralize by preventing a virus or toxin from binding to their target. B cells are highly specified to certain antigens - they don't produce a generic response to any invader. B cells devour and digest the antigen, and then, with the help of a matching T cell, the B cell multiplies and produces even more antibodies which lock onto antigens and mark them to be eliminated. This immunity is active because it is an active response from the immune system to an infection or vaccination.

In a cell-mediated response to infection, T cells attack self-cells that are infected. Cytotoxic T cells will attack and destroy infected cells before the pathogen can replicate and escape.

The immune system's memory cells are very important in ensuring a rapid and effective response to antigens. If memory cells have already identified an antigen, the body engages a secondary immune response, wherein there is a more rapid production of immune defenses. Vaccination can contribute to immune memory, making sure the response to the disease the vaccination for is swift, and the symptoms less severe.]]> 2022-05-25 18:00:08 UTC https://padlet.com/kshah29_4/2142ab93lvvhjdvx/wish/2199755351