Lymphatic System I. Non-specific Defenses The immune system is a body wide network of cells and organs that have evolved to defend the body against attacks by invaders. The targets of the immune defenses are infectious organisms such as,, parasites, fungi, and some protists. A. First line of defense- 1. Skin- tough and when intact. 2. Sweat- gives skin a ph of. 3. Mucus membranes- found along the and, and tracts. B. Second line of defense- 1. White blood cells- also called cytes. There are types, four are WBC s (a-d below), one is (II. on the next page). a. - they are the WBC s to go to the site of an injury to ingest an invader. They engulf a foreign invader by before they themselves self-. Neutrophils are lived / they only live a few days. b. - they are the WBC s to go to the site of an injury to ingest an invader. They too utilize phagocytosis + fuse with a to digest a foreign organism. The difference is that monocytes are lived. One type of monocyte is called a / big eater. c. - unlike neutrophils and monocytes, eosinophils fight off. They do this by discharging into a parasite to digest it. d. - these WBC s release that blood flow to an injured area / causes blood vessels to and makes capillaries so that blood clotting elements like can form a clot and so that phagocytes like and can engulf. In part one of the image, a penetrates the skin and brings bacteria along with it. The injured cells release
signals. Basophils detect these signals and release. This causes an response-redness, heat,. In part two and three, the capillary dilates and permeability allowing the 2 and blood elements to the site of the injury. In part four, the phagocytes have engulfed the bacteria and the wound is sealed so the capillary returns back to normal. Injured cells release chemicals histamine proteins (20 proteins that attract phagocytes) (mostly dead short-lived neutrophils + plasma that leaked out from the inflammatory response). 2. Natural killer cells- another non-specific second line of defense, but they are not WBC s. They work on infected cells and cells (i.e. like a ) and cause them to by attacking their cell membranes. 3. Body s thermostat- a fever helps to some invading microbes and increases of tissues / reactions in the body. 4. Anti-microbial - there are 3 types. a. have an / protein called that breaks apart the cell of bacteria. b. Complement - as previously mentioned are proteins that attach to a target invader to attract phagocytotic WBC s (neutrophils and monocytes). c. Interferons- when a cell is infected with, the infected cell secretes interferon proteins to body cells which alert and prepare the body cells to the invader. Interferons are important in stopping the spread of and viruses. II. Specific Defenses Specific defenses attack targets and are the line of defense. This is the 5 th type of WBC. They are called. C. Third line of defense- 1. Lymphocytes- there are two kinds. a. B-cells- are formed and finished in red. B-cells make -shaped proteins called that they then secrete to specific targets. b. T-cells- are formed also in red bone marrow, but are finished in the gland (located above the ). T-cells do secrete antibodies. Instead, they have on them to specific invaders.
A foreign molecule that elicits a response is called an. Specific because the antigen has unique poly and/or poly on its surface. The immune system is equipped to respond to or possibly of different specific. III. Immune System Anatomy The lymphatic/ immune system is made up of lymph which return fluid and to the circulatory system. Lymph are masses of honeycombed spongy tissue located primarily in the,, and. Some other organs of the immune system include the,, and. IV. When Antigens Enter At the heart of the immune response is the ability to distinguish between and. In other words, what belongs in the body and what is foreign. Every cell in us carries surface (proteins and sugars) that are recognized as self and are not attacked by the immune system. molecules / antigens also carry distinctive markers called that protrude from their surfaces. The immune system is able to recognize millions billions of distinctive non-self molecules and to respond by producing molecules such as that can match up with and counteract molecules.
Steps to how both a non-specific and specific immune response happen: 1. First the (i.e. a virus) enters the body through the or mouth. This notifies the non-specific WBC s and (i.e. a macrophage) to come and engulf the virus/es by phagocytosis. 2. The macrophage now does two things- it off a fragment from the virus then it on its own surface and it emits a chemical signal called. IL-1 will both the body s temperature and attract / activate a specific cell. The helper T has a on its surface that will bind with the displayed virus fragment / it is very. The activated helper T is just a, it cannot destroy the antigen. 3. After binding to the displayed fragment, the helper T emits out a chemical signal called to alert the troops. 4. IL-2 can causes 3 things to happen depending upon what type of antigen enters: A) IL-2 causes more specific cells to arrive. It then clones both short-lived helper T cells and longlived helper T cells. This occurs in both a response (humors = + ) and in a cell- response. B) With a humoral response, IL-2 notifies the and they begin to clone specific. Like before there are short-lived effector / B-cells and long-lived B-cells. The effector / plasma B-cells are able to antibodies into the. The antibodies then the antigens so they are easier for the macrophages to locate them and antibodies the antigens from infecting other cells by their surface proteins/carbohydrates. Plasma cells are able to release antibodies / second for 4-5 days. C) With a cell-mediated response, IL-2 notifies the / and they arrive at the body cells. Killer T cells are able to latch onto the infected body cell,, or a cell (like with donation) and secrete an called. Perforin pokes holes in the membrane, then fluids rush in causing the cell to. Like before there are both effector killer T cells and memory killer T cells.
The immune response is turned off after an infection ends by. The first time the body gets exposed to an antigen is called the immune response. In a period of about days the body creates thousands of effector and memory cells. The second time the body gets exposed to that same antigen is called the immune response. In a period of about days the memory cells respond. Q: While it is rare to get the same virus twice, why do some people get a virus twice? V. Antibodies Recall that antibodies bind to the on an antigen and that each antibody binds to a epitope. Another name for an antibody is an, abbreviated as. Antibodies are just that bind antigens at two binding sites located at the of the Y. This area is called the region because it differs for each antibody. The region that is the same for each antibody is called the region. There are different regions to antibodies, but millions if not billions of different regions.
is able to cross the and thus gives immunity to the fetus. is passed through breast which helps protect newborns. is involved with an response. Antibodies bind to antigens in several ways. Two important ones are called and. With neutralization, the antibodies the antigen so it cannot attach to cells. With agglutination, the antibodies together several antigens. In both cases, then digest the invaders. VI. Types of Immunity immunity relies on a person s immune system. immunity means that are from person to person. A) Active immunity- 1) This can be acquired when a person gets sick and the body creates effector and memory cells. 2) This can be acquired through a. A vaccine is just an antigen, given a person gets sick. It s often a / weakened form of an antigen, of an antigen, or the produced by the antigen. By giving the body a vaccine, it produces both effector and memory cells so if later on an / live antigen enters the body, the body can easily fight it off. B) Passive immunity- 1) Pregnant women passively pass immunity to their babies through the, then through breast milk. However, this is
-term protection (few weeks-few months) because antibodies break down. 2) Also, can be from a person who is already immune to a disease into a person who is immune. Once again, this is short-term protection due to antibodies breaking down. Q: If a person gets bit by a rabies infected animal, what would be in the shot the doctor gives to the patient? Q: What is a booster shot / why should you get a tetanus booster every 10 years? VII. Transfusions and transplants If you have type A blood, this means your RBC s have a on their surfaces for blood type only. This surface sugar is considered a. Which means the A molecule is not an antigen to its, but would be recognized as foreign in the body of person with a blood type. If you have blood type B, your RBC s have self-antigens on their surface. If you have blood type AB, you have both and self-antigens on your RBC s. If you have blood type O, you have of the self-antigens on your RBC s. Therefore, if a person with blood type receives a blood transfusion of blood type, the body will destroy the foreign A antigens by using. Blood Group O A B AB Antibodies present in the blood stream Will clumping/ agglutination occur if the following types were added: O A B AB Q: Which blood type is most common in the US? Q: Which blood type is the universal donor? Which is the universal receiver? Also present on the surface of some RBC s is the. This is a. If you have this self-antigen on your RBC s you are, if you do not have it you are. It was named after the monkey where it was first discovered. Problems arise when a is and her developing baby is (baby got it from the dad). Normally this shouldn t be an issue because blood doesn t cross the placenta. However, sometimes during delivery blood across and triggers the mom s immune system to make against the
Rh factor. The first baby is fine and healthy, but if the next child is the mom s immune system will think an invader is in the body and mount an attack against the fetus / cause it to naturally by sending out antibodies. Nowadays this situation is under control because doctors inject Rh- women with antibodies soon after delivering the first Rh+ baby. Recall this is just a -term way to stop her own immune system from responding (creating memory cells) because antibodies down. When it comes to or tissue transplants it is difficult to prevent the body from attacking the new organ. To increase the chances of it not being rejected, the transplant should be as of a match as possible. are also used that the immune system or parts of the immune system (like helper T cells) to increase the chances of the body accepting the transplant. VIII. Malfunctioning Immune System are a sensitive response to antigens called. An example-you re allergic to pollen ( ). Your body s cells release pollen antibodies ( ) into the bloodstream where they attach to a cell called a cell. Pollen enters through your tract and attaches to the located on the cells. Like basophils, mast cells are also full of the inflammatory agent. The bound allergens trigger the release of histamine into your bloodstream and the typical symptoms occur-watery eyes and, swollen passages/ difficulty, and. An example-you re allergic to / / / stings. The difference now is that with extreme allergies, mast cells release histamine. So blood vessels so quickly that your blood pressure and you go into shock or you die. Because of this, people with extreme allergies often carry an pen. Epinephrine/ adrenalin causes blood pressure to / blood vessels to.
IX. Autoimmune Diseases and Immunodeficiency Diseases immune diseases are when the immune system attacks molecules. Some examples of autoimmune diseases are: A) -the pancreas is attacked/ stops making insulin. B) -the body attacks its own DNA. C) -body attacks nerves of the central nervous system. D) Rheumatoid -the body attacks joints and cartilage. Immuno diseases mean the immune system is not combating antigens. An example of an immunodeficiency disease is (Acquired Immunodeficiency Syndrome). Caused by the retrovirus (Human Immunodeficiency Virus). HIV mostly targets the cells. Helper T cells bear a surface molecule on them called and this is what HIV looks for and infects. There are two major strains of HIV, and. HIV is a retrovirus because it has, not DNA. HIV enters the body through or semen and attaches itself mostly to helper T cells. It its RNA into the host helper T cell. RNA then gets into thanks to the enzyme located inside HIV called. This newly formed DNA then becomes a part of the DNA. It remains hidden inside the host s DNA for possibly. During this time, viruses off from the host cell and go make copies of themselves in other host cells.
The reason why HIV is so hard to combat is that each time the virus does inside a host cell, occur. This is because going from RNA DNA is backwards and thus has no steps. With normal DNA replication, checks to make sure DNA is copied correctly. Therefore finding a cure for HIV is challenging when the target keeps changing. Another reason HIV is difficult for the body to destroy is because as previously mentioned it inside the host s. In addition, when it does bud off from a helper T cell, it takes part of the cell s plasma! Once again, this helps it to go undetected. Not to mention that the cells that are supposed to be combating HIV (the helper T s) are the very ones that HIV has set out to. This is why most people infected with HIV die from infections like the because these infections take advantage of a weakened immune system. Q: When is HIV considered full blown AIDS? Q: Which drug is most commonly used to combat HIV?