Ch 45 Flashcards
monocytes
develop into microphages, they eat a lot
lymphocytes
most powerful but are saved for big reactions
immunology
study of internal defensive responses
immune response
recognizing foreign or dangerous macromolecules and responding to eliminate them, the body then tries to remember the invaders so that it can better respond if it happens again
pathogen
creates pain and sickness, bad
soluble
dissolved in blood
specific vs nonspecific
specific fights off one specific invader at a time, nonspecific is trying to keep everything out
nonspecific immune responses
provide general and immediate protection from pathogens, some toxins and drugs, and cancer cells
Which is quicker, nonspecific or specific responses?
nonspecific is quicker, specific may requires several hours to several days
specific immune responses
highly specific, include immunological memory (remembers what diseases you’ve had and how to fight them)
antigen
molecule specifically recognized as foreign or dangerous by cells of the immune system
antibodies
highly specific proteins that recognize and bind to specific antigens
invertebrate immune responses
they are always nonspecific, they use physical barriers such as cuticles, skin, and mucous membranes, they also use antimicrobial peptides which are soluble molecules that destroy pathogens, and finally they use phagocytosis which is the clean up crew that eats bad stuff
vertebrate nonspecific immune responses
1) first line defenses: physical barriers, skin, mucous linings of the respiratory and digestive tracts, 2) chemical defenses: mucin (in noses), lysosymes, stomach acid, 3) cellular defense, 4) systemic defense: getting a fever
antimicrobial peptides
shaped so that they can poke a hole in things that don’t belong, then those things slowly leak and die
soluble molecules that are important in immune responses (nonspecific)
antimicrobial peptides, proteins that destroy pathogens, regulatory peptides
cytokines (nonspecific)
signaling proteins that regulate interactions between cells, includes interferons: prevent viral reproduction and help destroy bad cells, interleukins: regulate interactions between white blood cells, can reset the body’s thermostat resulting in fever, and chemokines: signaling molecules that attract, activate, and direct the movement of various cells in the immune system like white blood cells
complement proteins
increase the chances than when the bacteria encounters a macrophage, it will be eaten, enhance the inflammatory response
interferons
interfere
interleukins
send signals to white blood cells
chemokines
induce cell movement
natural killer (NK) cells
destroy cells infected with viruses, destroy foreign or altered cells such as tumor cells
inflammatory response
triggered when pathogens invade tissues, vasodilation occurs, increased capillary permeability occurs (allows fluid and antibodies to leave the circulation and enter the tissues), and increased phagocytosis occurs
cell-mediated immunity (specific)
specific T cells are activated, proteins are released that destroy cells infected with viruses or other intracellular pathogens, uses T lymphocytes in the Thymus
antibody-mediated immunity (specific)
specific B cells are activated, these cells multiply and differentiate into plasma cells, which produce antibodies, the antibodies then bind to antigens, the B lymphocytes used are found in Bone marrow
phagocytes
destroy bacteria, includes neutrophils: the most common type of white blood cell, eats bacteria, and macrophages: large phagocyes that eat bacteria and release antiviral agents
lymphocytes
develop from stem cells in the bone marrow, T cells leave the bone marrow and mature in the Thymus, B cells mature in the bone marrow
antigen-presenting cells (APCs)
includes macrophages, dendritic cells, and B cells that function as ‘professional’ APCs, display foreign antigens as well as its own surface proteins
T cells
responsible for cell-mediated immunity, T cytotoxic cells (Tc cells) are the ‘killer T’ cells, there are also T Helper cells (Th) and memory T cells that remember the bacterial viruses your body has already fought, the thymus gland confers immunocompetence (the ability to make a specific immune response) on T cells by making them capable of distinguishing between self and non-self
B cells
responsible for antibody-mediated immunity, differentiate into plasma cells which produce antibodies, some activated B cells become memory B cells that continue to produce antibodies after an infection has been overcome
Major Histocompatibility Complexes (MHCs)
these ‘present’ the broken bits of an antigen to the other cells so they know what to look for, immune responses depend on a group of genes that encode MHC proteins, Class I MHC genes=self recognition, Class II MHC genes=APC-identification, every cell in the body can produce MHC I genes but only APCs can produce MHC II genes
cell-mediated immunity process
specific Tc cells are activate by a foreign antigen–MHC I complex on the surface of an infected cell (this is the cell’s 911 cry for help), a co-stimulatory signal and interleukins are also required, activated Tc cells multiply, giving rise to a clone, clone cells migrate to the site of infection, pathogen-infected cells are destroyed, activated Th cells give rise to a clone of Th cells, clone cells secrete cytokines, B cells and macrophages activated, the helper T cells activate Tc cells using cytokines to attack the invader, APCs express MHC 2 which activates the helper T cells
Antibody-mediated immunity process
B cells are activated when they combine with antigen, activation requirements: APC with a foreign antigen–MHC, and Th cell that secretes interleukins, APCs activate the Th cells, activated B cells multiply giving rise to clones of cells, cloned cells differentiate forming plasma cells, plasma cells produce specific antibodies, aka immunoglobulins
antigen-antibody complex
may inactivate the pathogen, stimulate phagocytosis, and activate the complement system (the complement system is like the ‘frosting’ on donuts that makes it more yummy and increases phagocytosis)
immunological memory
memory B and T cells remain in the body after an infection and can live for up to 10 years, they are responsible for long-term immunity
primary immune response
stimulate by the first exposure to an antigen
secondary immune response
stimulated by a second exposure to the same antigen, is more rapid and intense than the primary response
active immunity
develops as a result of exposure to antigens, may occur naturally after recovery from a disease, may be artificially induced by immunization with a vaccine
passive immunity
temporary condition, develops when an individual receives antibodies produced by another person or animal (such as when you get a blood transfusion or an injection of antibodies)
Human immunodeficiency virus (HIV)
attacks white blood cells, is a retrovirus (which means it injects RNA into cells), causes acquired immunodeficiency syndrom (AIDS), destroys helper T cells, severely impairs immunity
graft rejection
transplanted tissues have MHC antigens, immune response is stimulated, T cells destroy the implant
Rh incompatibility
an Rh-negative woman gives birth to an Rh-positive baby, Anti-D antibodies develop, Rh incompatibility occurs in future pregnancies but after the first the mother’s body has made antibodies against the protein that the baby makes but the mom doesn’t and her body tries to fight off the protein, injuring the baby
autoimmune diseases
diseases where the body attacks its own healthy cells, includes rheumatoid arthritis and multiple sclerosis (MS) which is an antibody response against human myelin
