47 terms

Chapter 21: Immune System

General function of the Immune System.
Identify and neutralize and destroy foreign substances.
Innate (non specific) Defense
1st line of defense: Skin, mucus membrane attack foreign substances without activating the immune system.
2nd Line of Defense: inflammation and anti -microbal, protein and phagocytes.
Adaptive (specific) defense.
includes humeral (B-cells) cell mediated (T-cells) immunity specific respone. They are systemic and require immune activation. This mya generate memory and are specific to particular pathogen.
Protective function of surface epithelia.
membrans that are difficult to penetrate . Made of stratified epithelium , keratinzed and waterproof. Sebacous glands secret sebum which is acidic and kills most bacteria.
Roles of digestive and respiratory mucosae.
Mucus traps particules before they can enter the blood.
2nd line of defense
inflammation,phagocytic cells, and nonspecific chemicals.
inflammatory process
leukocytosis( increase wbc) increase the presences of wbc which release inflammatory chemicals such as histamine.
increase leakage of blood vessels. Heat, redness, pain and swelling are a result of vasodilation.
increase white blood cell count
when the wbc stick to blood vessel endothelium at infection site.
White blood cells cross vessel wall.
WBC engulf pathogens and release inflammatory chemicals.
importance of phagocytes and natural killer cells in non specific defense.
Both and engulf pathogens and destroy cancerous cells without activating the immune system.
secreted by virus infected cells and makes other cells less likely to become infected by virus.
What causes a fever?
Is caused by pyrogen molecules released by leukocytes which reset the hypothalmus to higher temps.
fever help?
1. protect the body by increasing leukocytosis.
2. slows the reproduction of bacteria and viruses.
Complete Antigen
substances that is both immunogentic and reactive.
incomplete antigen. It must bind with a protein to become inmunogentic and reactive
Antigentic Determinate
Specific portion of an antigene which are immunogentic and reactive.
chemical "name tag" which provoke an immune response.
self peptid
are not immunogentic to our own bodies unless autoimmune disease has occur.
Foreign (non Specific) Antigen
provoke immune response.
The role of macrophages and antigen-presenting cells in adaptive immunity.
Macrophages non specifically engulf pathogen and display anti gentic determinate on there class II MHC proteins. At that point phagocytes are called APC and there job is to seek and activate lymphocytes with receptors that are complementary to the anti genetic determinate.
Immune competence
lymphocytes are programmed to fight off one specific antigentic determinate.
Self tolerance
lymphocyte are programmed to ignore body cells. baring self pepetids on there class I mhc Protein.
Antigene Challenge
occurs when an antigenetic determinate combines with a receptor on a symphocyte.
clonal expansion
mature lymphocytes rapidly reprodcue by mitosis
differation of b and t cells
is the process where lymphocytes take on specific roles.
Provide humeral immunity which is when antibodies target pathogenes in the blody fluids.
T cells
Cell mediated immunity which is when pathogenes or pathogen infected body cells are distroyed by t cells.
humoral immunity
B lymphocytes differntiate into plasma cells. which produce antibodies against pathogens in the body fluid.
recount the roles of plasma cells and memory b cells in humoral immunity.
memory b cells become active secondary immune respone. (2nd time you see the same pathogen)
Active immunity
the organism produce antibodies themselves in generate memory its systemic and its specific are antigenic determinate.
2 types of active immunity
Naturally occurred-which is getting sick
Artificial -vaccine with weakened pathogen.
Passive immunity
Another organism produces the antibodies. No Memory and immunity lasts about a week.
2 types of of Passive Immunity
Natural-passed from mother to fetus via breast milk or through palcenta.
Artificial-Injection with just antibodies.
Primary immune response
Peak 10 days after antigen challenge.
secondary immune response.
Antibody levels peak within 3 days memory b cells and anitbody levels are higher in blood plasma longer.
4 classes of organ transplant
1. autograf (self to self)
2.isograf (from identical twin)
3.allograft (among same species)
4.Zinograft (across species)
Cell mediated immunity
T lymphocyes (t-cells) directly attack pathogens or infected cells.
Helper T-cells
CD4 cells (helper tcells) They help activate cytotoxic t-cells and B cells
Cytoxic T cells
CD8 Cells Directly attack pathogens and infected t cells.
memory cells
Activate during 2nd immune response
cypressor t cells
which wind down the immune system.
HIV infects CD4 cells and weakens the immune system making you more susceptible to diseases.
Autoimmune disease
Immune system targets specific types of healthy body cells. RA, Lupus, etc.
Allergy. immune system over reacts.