They are attracted by chemical signals to infected areas. Once they arrive to an infected area they kill by respiratory burst
Tolerance
TRUE
Fever (beneficial?)
yes, kills antigens immunity replicates, speed up metabolism, kill them
Fever (Pyrexia)- A fever may develop in response to toxins produced by pathogens or due to pyrogens released by leukocytes. While a high fever is dangerous (1040F), moderate fevers inhibit the growth of some microorganisms. The high body temperature inhibits some microbial growth and speeds up body reactions that aid repair.
Eosinophils (what do they kill?)
parasitic worms
Contain destructive enzymes in cytoplasm granules which are discharged against the outer covering of the invading pathogen
Cancer cells and virus-infected body cells are killed how? (What do they kill?, who hunts down?)
Natural Killer Cells
1. Kill aberrant cells that could form tumors
2. Destroy body's own infected cells, especially those harboring viruses. Are not phagocytic, but attack membrane, causing lysis. NK cell recognizes abnormal cell then secretes perforins, which bind to the enemy cell and make holes in the membranes
3. Theory of Immunological Surveillance
Inflammatory Response (stages, sings & symptoms)
Inflammatory Response occurs when there is damage to a tissue due to physical injury or infection.
Purpose: restore tissue homeostasis by-
1. Protecting and defending by eliminating microbes, toxins, or foreign material from site of injury
2. Preventing the spreadof microbes, toxins, or foreign material to other organs
3. Preparing the site for tissue repair
Stages:
1. Vasodilation (widening)
2. Increased permeability of blood vessels
3. Phagocyte migration
4. Repair
Symptoms:
1. Redness
2. Pain
3. Heat
4. Swelling
5. Loss of function
Chemotaxis
Phagocytes are attracted to the damaged tissue by several chemical mediators (chemotaxis)
Phagocytic cells (2 main inflammatory -hystamine and protagladins)
Chemical signals are important to initiate inflammatory response:
1. Histamine- released from injured circulating basophils and mast cells in the connective tissue. Released histmaine causes localized vasodilation and the capillaries in the area to become more permeable=leakier
2. Protaglandins- released from WBC and damaged tissues. promotes increased blood flow to the injured area.
Phagocytic cells (Types of WBCs)
1. Neutrophils(60-70%)
1st to arrive at the scene
attracted by chemical signals to infected areas methods of killing 1. Phagocytosis 2. Respiratory burst *
2. Monocytes(5%)
enter tissue become Macrophages(larger)
kill: 1.Phagocytosis * 2. Respiratory Burst
Types of Macrophages:
1. Alveolar macrophages- dust cells in the lungs
2. Histiocytes- in connective tissue
3. Kupffer cells- in liver
4. Microglial cells- in neural tissue
Dentric cells- in epidermis, oral mucosa, esophagus, vagina, and lymphatic organs
3. Eosinophils(1.5%) limited phagocytic activity
1. Kill Parasitic worms
2. contain destructive enzymes in cytoplasm granules which are discharged against the outer covering of the invading pathogen.
seeNatural Killer Cells
Basophils
Basophills (<1%)
store histamine
IgE. A Y-shaped monomer. Stem regions attach to receptors on mast cells and basophils; stimulates these cells to release histamine and other chemicals that cause allergic reactions when triggered by an antigen.
against colonization by viruses and bacteria and provide a 2nd line of defense should microbes penetrate the skin and mucous membranes
released by virally infected cells
INFs also enhance the activity of phagocytes and NK cells, inhibit cell growth, and suppress tumor formation
most effective against short-term infections (colds, influenza)
Cytokines Interferon(chemical messengers)
cytokines- chemicals secreted by one cell as a regulator of neighboring cells
regulate B and Tcells
involved in both humoral and cell-mediated responses
What are antigens?
foreign to the body
Physical barriers to invasion
Complement
Complement proteins,When activated- enhance certain immune, allergic, and inflammatory reactions
antimicrobial substance,work against colonization of viruses and bacteria and provide 2nd line of defense should microbes penetrate the skin and mucous membranes
group of 20 proteins present in blood plasma and on cell membranes.
Inflammatory Response (signs symptoms and stages)
see #7
Opsonization
(complement Protein way to kill pathogenss in 3 ways 2. Oponization)
copperative mechanism in which complement proteins attach to a foreign cell and stimulate phagocytes to engulf the cell
An alarm substance that triggers an inflammatory reaction is ________.
**Histamine**
Inflammatory Response
see #7
Vaccination
Artificial Active Immunity
vaccine consists of either dead or attenuated (weakend) pathogens which can stimulate the body's immune response but normally cause little or no discomfort or disease.
long lasting due to memory cells are produced
the production of one's own specific immunity cells as a result of vaccination against disease
If a person's bone marrow were destroyed by radiation what cells would be affected?
**ALL**
Physical barrier to infection
Interleukin-1 (what type?)
what type? - *Cytokin*
Interleukin-1- secreted by leukocytes
Macrophages
derive from Monocytes
destroy pathogens by phagocytosis, clean up the remains of damaged tissue cells and dead neutrophils
Monocytes (5%) enter tissue become Macrophages (larger)
kill: 1.Phagocytosis * 2. Respiratory Burst
Types of Macrophages:
1. Alveolar macrophages- dust cells in the lungs
2. Histiocytes- in connective tissue
3. Kupffer cells- in liver4. Microglial cells- in neural tissue
Complement (how it kills?)
kills 3ways:
1. Membrane attack complex- the complex lyses the pathogen.
2. Oposonization- cooperative mechanism in which complement proteins attach to a foreign cell and stimulate phagocytes to engulf the cell
3. Immune adherence- complement proteins and antibodies coat a microbe which causes it to adhere to blood vessels walls and other surfaces' this makes the cell easy prey for circulating phagocytes
The following events occur when the immune system first encounters a pathogen. Place them in a correct sequence, and then choose the answer that indicates that sequence.
III. Antigenic determinants from pathogen bind to antigen receptors on lymphocytes
IV. Lymphocytes specific to antigenic determinants from pathogen become numerous
II. Lymphocytes secrete antibodies
V. Only memory cells remain
Plasma cells (function, what pathway AMI plasma cells are effector cells)
Antibody Mediated Immunity (AMI) plasma cells are effector cells
function- produce and secrete antibodies by other means
spleen is a site of B cell proliferation into plasma cells
Cytokines
Chemical Messengers
cytokines- chemicals secreted by one cell as a regulator of neighboring cellsregulate B and Tcells involved in both humoral and cell-mediated responses
Interferon- secreted by virally infected cells
Interlukin I&II- secreted by leukocytes
Perforin
creates holes in plasma membranes
released by Cytotoxic T cells "effector cells" (warriors)
lethal cytotoxic chemical
Helper T cells
Cell Mediated Immunity
Helper T cells promote the action of cytotoxic cells as well as playing key roles in AMI and nonspecific defense. ALL other T cells are in CMI only
Suppressor T cells (function)
down regulate the immune response
A doctor discovers that her patient can produce antibodies against some bacterial pathogens, but he is unable to protect himself against viral infections. The doctor suspects a disorder in her patient's (what type of cell)
Which of the folowing is true for both T cells and B cells?
lymphocytes
effectors
produced in bone marrow
Allergy attack
IgE- a Y-shaped monomer. Stem regiions attach to receptors on mast cells and basophils; stimulates theses to release histamine and otehr chemicals that cause allergic reactions when triggered by an antigen
AIDS
T-helper cell
Antibodies of the different classes IgM, IgG, IgA, IgD, and IgE differ from each other in ( how do they different? different functions)
different functions
add more
Clonal Selection
CMI1. a macrophage calls the T-helper cells to him by releasing interlukin-1
2. A T-helper cell with the correct surface receptor will hook up with the macrophage. When a T-helper cell binds to antigen-presenting macrophage recognition occurs which causes the T-helper cells to begin to multiply (clonal selection).
3. When the T-helpers multiply we also at this time set some of these aside to become T-helper memory cells.
4. Activated T helpers secrete interlukimn II
5. Interlukin II does two important things:
1) Calls cytotoxic T cells to the infected area so that they can become activated
2) Activates B cells that also have the ability to recognize this particular antigen.
6. Activated cytotoxic T cells go out and destroy infected host cells
7. Once the pathogen has been defeated suppressor T cells down regulate the immune response
Cell-mediated immunity is mostly the function of what type of cell
**T cell**
Active Immunity v. Active Immunity
(active-long lasting since memory cells are produced) 1. Natural Active Immunity- production of one's own specific immunity cells as a result of exposure to an antigen
2. Artificial Active Immunity- production of one's own specific immunity due to vaccination
Passive:
1. Natural Passive Immunity- temporary immunity that results from acquiring antibodies produced from another individual (ex: from mom to fetus or baby)
2. Artificial Passive Immunity- temporary immunity that results from the injection of an immune serum ontained from another or from an animal that produced antibodies against a certain pathogen (2-3weeks)
Humoral Immunity (Antibody Mediated Immunity AMI)
(AMI) B cells are responsible fro the Humoral Immunity (AMI)
B cells defend by generating specific antibodies
(2-subpathway T-independent- long chains of proteins trigger humoral immune response without macrophage or T cell involvement)
Secondary Immune Response
occurs when the body is exposed to a previously encountered antigen response is faster (3-5d) and more prolonged than a primary response.
function: produce and secrete antibodies to tag antigens for destruction by other means
some activated Bcells turn into Plasma cells (proliferation) in the spleen
protection by antibodies that cross the placenta from mother to fetus?
**passive natural**
Types of T cells
Cytotoxic T cells- (EFFECTOR CELLS) of CMI
1. Perforin 2. Lymphotoxin- destroys targets cell's DNA 3. Tumor necrosis factor (TNF) kills cancer cells by unknown mechanisms
Helper T cells (ON switch)- promote action of cytotoxic Tcells as well as playing key role in AMI and nonspesific defense. (all others involved in CMI only)
Suppressor Tcell (OFF switch)- limit CMI attack and keep the immune system from running out of control (regulatory lymphocytes)
Memory T cells- are descended from helper T and cytotoxic T cells and are responsible for memory in CMI
Antigen Presenting Cells (APC's)= macrophages and infected body cells
Lymphocytes (characteristics)
made in the bone marrow
antigen receptors present on both
mature- lymph nodes, spleen, other lymph organs
B cells- Humoral immune response or AMI generate antibodies, membrane bound antibdy molecuels which recognize specific antigens
T cells- CMI response, only respond to antigenic epitopes displayed on surfaces of the body's own cells. T cells cannot detect free antigens in the body fluids. receptors are proteins embedded in the membrane which recognize specific antigens
Function of CD4 and CB8
CD4- interactions T helper and APCs (antigen present cells)
CB8- enhances recognition Cytotoxic T cell and infected cell
Interleukin-I
Interleukin I&II- Cytokins
Macrophages release Interleukin-I to call T-helper cells to come to him for recognition for clonal selection
Interleukin-II
Interleukin II-released by (Activated T-helper cells)
1. calls Cytotoxic T-cells so they become activated too
2. activates B cells that also have the ability to recognize the particular antigen
Perforin Mechanism
released by Cytotoxic T-cell
creates holes in the plasma membranes
Plasma cells
see #28
Antibody production by plasma cells
Antibodies made up of Immunoglobulins (Ig)
Y-shaped, 4 amino acid chains
(V) VARIABLE REGION not stem
Characteristic of specific defenses include (omit)
immunoglobulins
immunoglobulins
immunoglobulins
immunoglobulins
variable region of an antibody (function) BCR recognition
(V) is the variable region of an antibody
The binding of an antigen to an antibody can result in?
replicate stimulate immune response
form antigen-antibody complex which tags the invader for destruction by:
1. Neutralization- simple, blocks viral attachment sites or coats a bacterial toxin, making them ineffective
2. Agglutination- antigens cross-link and hold back clumps of bacteria
3. Precipitation- cross-linking of soluble antigen molecules instead of cells (corner them)
4. Complement fixation- activation of the complement system, combine with complement proteins, result in cell lysis
In order for a lymphocyte to respond to an antigen, the antigen must
*match*
When an antigen is bound to a class I MHC molecule, it can stimulate a ______ cell.
**T helper cell**
Class II MHC molecules are found only attached to which of the following
Macrophages
When an antigen is bound to a Class II MHC molecule, it can stimulate a _______ cell.
T-helper cell**
B cells are primarily activated by the activities of
Secreting T-helper cell of Interleukin II
The following are steps in the cell-mediated immune response
2. Antigen is engulfed and presented by a macrophage
4. Undifferentiated T cells with specific receptors recognize the antigen
1. Several cycles of mitosis occur (cloning)
5. T cells differentiate into cytotoxic T cells and T memory cells
3. cytotoxic T cells migrate to site of infection
6. cytotoxic T cells release perforin and/or lymphotoxin
Interlukins (function)
Newborn infants gain most of their immunity from (active or passive mom)