Study sets, textbooks, questions
Upgrade to remove ads
The Immune System
Terms in this set (74)
-protects the body from foreign substances and pathogenic (germs) organisms.
-anything that generates an immune response.
-usually consist of portions of proteins found on the exterior of pathogens.
-non-infectious particles to which the body lacks tolerance.
-non-living infectious particles. They consist, at minimum, of an outer protein shell and inner nucleic acid.
Viral Life Cycle
-the outer protein coating (capsid) binds to specific proteins/receptors on the exterior of a cell. Then the genetic material is injected into the cell. The viral genetic material hijacks the cell, forcing it to make viral components. The virus particles assemble into viruses. The cell ruptures and many viruses escape to infect other cells.
-just like in the other cycle, the virus binds to a cell, and injects its genetic material. The viral DNA inserts itself into the host DNA. When the host cell replicates its DNA, it also replicates the viral DNA. After some time, the viral DNA excises itself from the host DNA, and then hijacks the cell turning it into a virus factory. The host cell lyses, letting many viruses escape to infect other cells.
Nonspecific (Innate) Defenses
-Intact Skin,Mucus Membranes (Mucosa) Defenses, Natural Flora, Phagocytic Cells, Natural Killer Cells, Granuloocytes
-the skin is a physical barrier to the invasion of microorganisms. The skin is dry/dead, and is covered in slightly acidic secretions. This inhibits microbial growth.
Mucus Membrane (Mucosa) Defenses
-the flushing action of urine helps to prevent pathogens from reaching the bladder. Mucus entraps foreign substances in the bronchi and throat. The action cilia carries up the trachea and down the stomach. The movement of bolus, digestive enzymes, and the low pH of the stomach all help limit most microorganisms to the colon. Blinking and the presence of lysozyme in tears help prevent bacteria from colonizing the eye. Lysozyme destroys bacterial cell walls.
-the skin, mouth, colon, sinuses, and the throat have been colonized by bacteria. These bacteria can provide vitamins and caloric intake to the host. In addition, they physically prevent pathogenic bacteria from having room to grow.
-Macrophages and Dendritic Cells
Macrophages and Dendritic Cells
-these cells devour bacteria and other foreign substances. They can activate other immune cells. Dendritic cells are primarily found in the skin and mucosa.
-are activated to become macrophages when they leave the blood and enter the tissue.
Natural Killer Cells (NK Cells)
-these cells examine the surface of other host cells. Cancerous and virally infected cells often have unusual receptors on their surfaces. If the host receptors are unusual, the NK cell triggers apoptosis.
-program cell death
-contain granules and have lobed nuclei
-Neutrophils, Eosinophils, Basophils
-the most common phagocytic cell in the body. They also produce some antimicrobial compounds. (They are the major component of pus).
-these cells release large amounts of toxic substances, including lysozyme, acids, and peroxide compounds. They are particularly useful in fighting multicellular parasites.
-these cells help regulate the inflammatory response, activate other grandulocytes, and produce some antimicrobials.
-proteins in the blood begin to activate and bind to the surface of the bacteria. The binding of these proteins to bacteria makes it easier for phagocytes to 'eat' them. This is called opsonization. These proteins can bind in the shape of a ring, forming the membrane attack complex (MAC). This burrows a hole in the bacteria cell membrane, leading to bacterial cell death.
-the binding of these proteins to bacteria makes it easier for phagocytes to 'eat' them.
Membrane Attack Complex (MAC)
-burrows a hole in the bacteria cell membrane, leading to bacterial cell death.
-this is produced by a virally infected cell. It activates proteins in nearby cells, which can inhibit protein syntheses and other cellular functions used by viruses. This leads to the premature death of virally infected cells. This also calls immune cells to the area and activates them.
-these proteins are found on the surface of many immune cells. They specifically bind substances not found on mammalian cells, but commonly found on/in pathogens. Once binding occurs, this activates the white blood cell.
-inflammation is characterized by redness, swelling, heat, and pain. Inflammation can cause fever (which may inhibit some viral replication and increase T cell activity), and summons many immune cells to the area.
-swelling caused by excess fluid in the body tissues
-inflammation can cause fever and summons many immune cells to the area.
Specific (Adaptive) Defenses
-these bind to cancerous and virally infected cells. It then triggers them to undergo apoptosis.
-these coordinate the body's defenses. They start the cell-mediated response by activating cytotoxic t-cells and they start the antibody-mediated response by activating b-cells.
-these cells make antibodies.
-each antibody have four parts; two light chains and two heavy chains. The chains are held to one another by disulfide bonds. At one end, the antibody is always the same. The other end has two unique antigen-binding sites. These binding sites will bind to a specific part of a molecule. Each different B cell makes a different antibody.
-the antibody that is always the same.
-has two unique antigen-binding sites.
Types of Antibodies
-the main type of antibody. It is important mid-to-late in fighting an infection. It binds to antigens (preventing them from binding to host cells), activates complement, and performs opsonization. It crosses the placenta
-this is a pentomer. It is early in fighting an infection. It is excellent at activating complement and clumping microbes together for easy disposal.
-this antibody is secreted and it is a dimer. This passed to infants in breast milk. They also help prevent pathogens from binding to the respiratory and digestive tracts and are found in tears.
-this is usually found on the surface of B-cells. Antigen binding helps activate the B-cell.
-this is the least common type of antibody in the blood. It is particularly good at binding large objects, like multicellular parasites and allergens.
Inflammation and Fever Steps
-there are a number of ways the inflammatory response can be started. In each case, mast cells and/or basophils are activated. Histamine causes capillaries to dilate increasing their permeability. Fluid leaves the capillaries causing the area to swell, redden, heat up, and become more painful. Histamine also called phagocytes to the area, and helps them move from the capillaries to the site of infection/injury.
-are white blood cells which exist in the tissues. When activated they secrete histamine. Basophils and olamaged cells can also secrete histamine.
-histamine also called phagocytes to the area, and helps them move from the capillaries to the site of infection/injury.
-factors that are released from activated phagocytes. These travel via the bloodstream to the hypothalamus and tell it to raise the body temperature.
-a component of the outer membrane of some bacteria. Low amounts of it enhance the inflammatory response and the release of pyrogens. Large amounts of it can send these processes into overdrive. Shock and high fevers resulting from this can be deadly.
The Lymphatic System
-a series of organs and lymph vessels which promotes homeostasis.
Lymph (Interstitial Fluid)
-the tissue fluid of the body. It contains nutrients, waste, hormones, enzymes, etc. Produced elsewhere in the body.
Functions of the Lymphatic System
-it absorbs excess body tissue fluid and returns it to the bloodstream. It absorbs lipids digested in the small intestine and transports it to the bloodstream. It produces, maintains, and distributes lyphocytes. It helps protect the body from pathogens and cancer.
-T cells and B cells
Red Bone Marrow
-homatopoesis occurs here creating all red and white blood cells. B-cells matures here.
-immature T-cells migrate here to mature the 'learn' to distinguish 'self' from 'non-self'.
-immature T-cells are given a signal to live if they bind/recognize the MHC. Immature T-cells which bind the MHC too tightly and thus are likely to recognize 'self' proteins as foreign are signaled to undergo apoptosis. Only 2-5% of immature T-cells entering the thymus leave as mature T-cells.
MHC (Major Histocompatibility Complex)
-this receptor is found on all cells except RBCs. On this receptor, the cells present fragments of proteins from their cytoplasm. Strange proteins such as those made by cancerous and virally infected cells will display. 'Normal' proteins will, too. This is what natural killer and cytotoxic t-cells examine on the surface of cells.
-small sacs which filter lymph and are packed with white blood cells.
-this organ filters lymph and blood.
Mucosa Associated Lymphoid Tissue (MALT)
-aid in the defense of the intestines.
-aid in the defense of the throat.
Entry of the Immune Response
-the (new) pathogen bypasses the skin and/or mucosa and enters the tissues.
Phagocytic Action of the Immune Response
-inflammation calls the phagocytes to the site of infection. The phagocytes engulf and digest the pathogens. A small amount of parts of the pathogens is placed on receptors on the surface of phagocytes. These cells are now APCs (Antigen Presenting Cells).
Helper T cells Activation of the Immune Response
-the APC travels to a lymph node and interacts with a naive helper t-cell. Only the unique t receptor on a helper t-cell is able to bind the antigen on the APC. (Other helper t-cells with different t receptors cannot bind). Receptor binding activates the helper t-cell. After a threshold number of help t-cells are activated, the specific immune response truly begins.
Clonal Selection of the Immune Response
-the activated helper t-cell proliferate into a large number of clones. Based on the antigen, the helper t-cell either activates primarily cytoctoxic t-cells or B-cells which can bind the antigen. Thee lymphocytes are then activated and proliferate into a large number of clones.
Migration of the Immune Response
-the specific, activated lymphocytes leave the lymph nodes and migrate into the tissues. The activated clones release chemical signals which activate other white blood cells, such as macrophages.
Memory of the Immune Response
-after the pathogens are eliminated, the immune response begins to be down-regulated. Most of the cloned lymphocytes die. However, a small number of them differentiate into memory cells. These memory cells are long-lived and can circulate throughout the body. If activated by the reappearance of the antigen, the memory cells initiate a stronger and faster immune response.
AIDS (Acquired Immune Deficiency Syndrome)
-HIV (Human Immunodeficiency Virus)
HIV (Human Immunodeficiency Virus)
-target helper t-cells. The lysogenic virus kills these cells via lysis or apoptosis indused by a cytotoxic t-cell. Once helper t-cell numbers droop below a certain level, the specific immune response is stopped. The host is killed by other, opportunistic pathogens.
SCID (Severe Combined Immunodeficiency)
-this genetic disorder is caused by an error in the genes which encode the T, B, or APC receptors. As a result, there is no specified immune response. A bone marrow transplant can cure this disorder.
Allergies and Asthma
-the specific immune system recognizes certain antigens found on food, pollen, spores, etc. IgE are made in response and bind the antigen. Mast cells bind the bound IgE, and produce histamine. An inappropriate inflammatory response follows.
-a body-wide severe allergic reaction, which induces shock and can obstruct airways.
-this is a cancer of blood cells. If the white blood cells are cancerous, this can result in non-functional white blood cells (and thus a non-functional immune system) or white blood cells which attack normal cells. Chemotherapy, radiation, and bone marrow transplants are the most common treatments.
Recommended textbook explanations
Texas Science Fusion: Grade 7
Kenneth R. Miller, Levine
Kenneth R. Miller, Levine
Nelson Science Perspectives 10
Christy C. Hayhoe, Doug Hayhoe, Jeff Major, Maurice DiGiuseppe
Sets with similar terms
Test 2 - immunity
MASTERING BIOLOGY HUMAN BIOLOGY CHAPTER 9 IMMUNE S…
bio test 3 chapter 43
Other sets by this creator
The Cardiovascular System
Civil Rights and Liberties
The Immune System
The Sense Organs