Chapter 21- Immune System Flashcards
Innate Immunity
- Functional at birth
- No memory (nonspecific defense)
Adaptive Immunity
- Develops as a person ages
- Memory (specific defense)
Both types of immunities..
work together to protect the body (at the same time, not individually)
Components of innate immunity:
Species Resistance
Mechanical Barriers
Chemical Mediators
Natural Killer Cells
Phagocytes
Inflammatory Response
Fever
Pathogen
Harmful or disease-causing organism
Species Resistance
Some diseases are unable to spread to individuals of different species. Pathogens are almost always species-specific
Zoonotic
When a pathogen affects multiple species
ex: Rabies
Mechanical Barriers
- Considered the body’s 1st line of defense
- Skin- protective as long as it’s unbroken
- Mucous membranes are also protective: stomach (HCL), saliva and tears (lysozyme)
______ is an enzyme that destroys bacteria and is a part of ____ and _____
Lysozyme
Saliva and tears
Chemical Mediators
- 2nd line of defense
- Includes interferon and complement
Interferon
Antiviral substance produced by cells (toxic to viruses)
NOT virus specific
How do interferons work?
It protects neighboring unaffected cells
Complement: group of..
Group of 20 plasma proteins that circulate the blood
Examples of complement activites (summary)
- Membrane Attack Complex
- Inflammatory response (chemotaxis, histamine)
- Opsonization
Complement activity (1)
- Alters membrane chemistry and causes lysis. MEMBRANE ATTACK COMPLEX
Complement activity (2)
- Serves as chemotaxis agents during inflammation. Stimulates the release of HISTAMINES. This increases permeability of blood vessels in injured area.
Complement activity (3)
- Helps phagocytes to adhere to the pathogen (OPSONIZATION)
Opsonization can also be termed as
enhancing phagocytosis
Natural Killer Cells
Unique WBCs that police the body in the blood/lymph
Attaches themselves to the target cell and destroys the membrane (and the cell)
Natural killer cells are ___ ____
not specific
Natural killer cells secrete..
perforins (creates a hole and then everything leaks out)
Natural killer cells work well against..
viruses and cancer
Phagocytes: pathogens that get through the skin and mucosa will be confronted with phagocytes. The chief phagocytes are ____, which..
Macrophages which derive from circulating monocytes
2 types of macrophages:
Wandering macrophages- wanders through the interstitial spaces in search of invaders
Fixed macrophages- remains within organs. ex: kupffer cells in liver
Also apart of phagocytes are _____ and ______. Sometimes the phagocytes are unable to ____ to the invader and therefore cannot ingest it.
Eosinophils and neutrophils
Adhere
Inflammation- the inflammation response will:
- Keep the infection localized
- Dispose of debris and pathogens
- Set the stage for repair
- Alerts the adaptive immune response
4 signs of inflammation:
redness, heat, swelling, pain
*in more serious injuries, there may be a loss of function (categorized under pain)
Tissue injury leads to the release of various chemicals including:
prostaglandin, complement, histamine, and leukocytosis-inducing factors
These chemicals (PG, complement, histamine, LIF) result in a number of different effects (summary):
chemotaxis
dilation of vessels
increased permeability
These chemicals result in a number of different effects:
a. dilation of blood vessels injured tissues in area, which allows for more blood in area
_______ and ______
b. Increase permeability of capillaries to allow for emigration.
c. increase amount of blood in vessels in injured area will lead to increase pressure within capillaries,
resulting in more fluid escaping into interstitial spaces = _______
d._____ is caused when this edema puts increased amount of pressure on nerves.
e. chemotaxis of WBCs. This is primarily due to _______________ released
from injured cells and stimulate rapid release of _______(4-5x).
a. dilation of blood vessels injured tissues in area, which allows for more blood in area
REDNESS and HEAT
b. Increase permeability of capillaries to allow for emigration.
c. increase amount of blood in vessels in injured area will lead to increase pressure within capillaries,
resulting in more fluid escaping into interstitial spaces = SWELLING.
d. PAIN is caused when this edema puts increased amount of pressure on nerves.
e. chemotaxis of WBCs. This is primarily due to Leukocytosis - Inducing Factors released
from injured cells and stimulate rapid release of NEUTROPHILS (4-5x).
Within 1 hour after the inflammation response has begun, neutrophils have collected at the site of injury and are actively devouring bacteria, toxins and dead tissue cells. As the attack continues, the neutrophils will be followed by ________ that enter the area from the bloodstream. These monocytes are poor phagocytes, but within 8 - 12 hours after entering the tissues, they swell (and increase the # of lysosomes in the cytoplasm) and become very phagocytic and are called _________
Therefore, neutrophils are found in early stages of infection and macrophages arrive later to do the final cleaning of the infected area (getting rid of pathogen and dead neutrophils).
Within 1 hour after the inflammation response has begun, neutrophils have collected at the site of injury and are actively devouring bacteria, toxins and dead tissue cells. As the attack continues, the neutrophils will be followed by MONOCYTES that enter the area from the bloodstream. These monocytes are poor phagocytes, but within 8 - 12 hours after entering the tissues, they swell (and increase the # of lysosomes in the cytoplasm) and become very phagocytic and are called MACROPHAGES.
Therefore, neutrophils are found in early stages of infection and macrophages arrive later to do the final cleaning of the infected area (getting rid of pathogen and dead neutrophils).
In severely infected areas, _____ may accumulate at the sight of infection. A large area of pus is classified as an ______
In severely infected areas, PUS may accumulate at the sight of infection. A large area of pus is classified as an ABSCESS.
Pus is a mixture of..
Pus is a mixture of dead neutrophils, broken down tissue cells, pathogens, macrophages.
Fever
- Protective mechanism against ______
- Due to the release of _______
- Effects on _______ in the brain (_______)
- _______ temperature
- Protective mechanism against PATHOGEN
- Due to the release of PYROGENS
- Effects on PROSTAGLANDIN in the brain (HYPOTHALAMUS)
- RESETS temperature
Pyrogens are secreted by
lymphocytes, neutrophils, and macrophages
Explain how aspirin works:
Antiprostaglandin
2 effects:
1. fevers- lowers temperature to get rid of fever
2. inflammation- gets rid of the red/heat/swelling/pain
Adaptive Immunity:
While the nonspecific defenses all offer immediate protection to a variety of pathogens or foreign substances, adaptive immunity defends the body against ______ invaders by the production of specific cells and antibodies.
While the nonspecific defenses all offer immediate protection to a variety of pathogens or foreign substances, adaptive immunity defends the body against SPECIFIC invaders by the production of specific cells and antibodies.
Substances that stimulate adaptive immunity are called ______. Antigens can be classified as being either _____ antigens, antigens not produced by the body but introduced from the outside, ( ex. bacteria, viruses, parasites, transplanted tissue) or ____-_____, molecules produced by the body that stimulates an adaptive immune response (basis of ________ ______).
Substances that stimulate adaptive immunity are called ANTIGENS. Antigens can be classified as being either FOREIGN antigens, antigens not produced by the body but introduced from the outside, ( ex. bacteria, viruses, parasites, transplanted tissue) or SELF-ANTIGENS, molecules produced by the body that stimulates an adaptive immune response (basis of AUTOIMMUNE DISEASES).
Adaptive immunity results from the activities of 2 types of lymphocytes, the ___ cells and the ___ cells. These cells have been programmed at ____ to respond to specific antigens coded for by the genes the individual has. In a lifetime, most of the T and B cells will never be challenged
Adaptive immunity results from the activities of 2 types of lymphocytes the T cells and the B cells. These cells have been programmed at birth to respond to specific antigens coded for by the genes the individual has. In a lifetime, most of the T and B cells will never be challenged
There are 2 requirements that must be met in order for the T/B lymphocytes to be successful in their attack –
- Lymphocytes must recognize the specific antigen.
- After recognition, the lymphocytes must increase in number to effectively destroy the antigen.
- ______ after getting an infection
Memory
Adaptive immunity:
Consider species resistance- if it’s something we as a human can get, ______________.
Could the lymphocytes recognize heartworm?
Consider species resistance- if it’s something we as a human can get, T/B cells can recognize it
No
Antigenic Receptors on T and B cells: As T and B cells are produced, they develop receptors that are programmed to recognize different ________ ______/______. These specific regions of a given antigen will be recognized by specific populations of T and B cells.
Antigenic determinants/epitopes
What is the variable region of an antigen called?
Epitopes
Recognition of Antigen by T and B Cells: Although some antigens bind to their receptors and directly activate B and T cells, most lymphocyte recognition involves glycoproteins on the cells called ______ ___________ ________. MHCs are unique to each individual unless s/he has an identical twin. They are found on all cell membranes except _____ Once recognition occurs, the specific lymphocyte goes through cell division, increasing the number of cells equipped to destroy the antigen.
Recognition of Antigen by T and B Cells: Although some antigens bind to their receptors and directly activate B and T cells, most lymphocyte recognition involves glycoproteins on the cells called MAJOR HISTOCOMPATIBILITY COMPLEXES (MHCs). MHCs are unique to each individual unless s/he has an identical twin. They are found on all cell membranes except red blood cells. Once recognition occurs, the specific lymphocyte goes through cell division, increasing the number of cells equipped to destroy the antigen.
MHC 1
nucleated
found on fixed cells
MCH 2
found on wandering cells
MHC is a
surface molecule that displays antigens
Many times _____ _____ _____ are necessary in recognition between antigen and its specific cells. These include ________, which must first phagocytize the antigen. The partially digested antigen is then “displayed “ on the surface of the macrophage and “presented” to the T and/or B cells for recognition. These will be found associated with the MHC molecules.
As a result, ______ _______ is needed:
Many times ANTIGEN PRESENTING CELLS are necessary in recognition between antigen and its specific cells. These include MACROPHAGES, which must first phagocytize the antigen. The partially digested antigen is then “displayed “ on the surface of the macrophage and “presented” to the T and/or B cells for recognition. These will be found associated with the MHC molecules.
As a result, DOUBLE RECOGNITION is needed:
Recognition between the specific antigen and its T and B lymphocytes also needs __________ with cytokines and other cells called _______ __ ______. These are the type of cells that proliferate first when meeting an antigen through their secretion of ________ (a cytokine). The specific T/B cells increase and will be directly responsible for destroying the antigen by _________ of these specific lymphocytes into identical cells called a ____.
Recognition between the specific antigen and its T and B lymphocytes also needs COSTIMULATION with cytokines and other cells called HELPER T CELLS. These are the type of cells that proliferate first when meeting an antigen through their secretion of INTERLEUKIN (a cytokine). The specific T/B cells increase and will be directly responsible for destroying the antigen by PROLIFERATION of these specific lymphocytes into identical cells called a CLONE.
Clone
A population of identitical cells
Activation of T cells
Cell mediated immunity
Activation of B cells
Humoral immunity
Costimulation
Interaction between leukocytes
T lymphocyte activation cells involve:
Cytotoxic T
Helper T (Th1)
Memory T
Regulatory T
B lymphocyte activation cells involve:
B cells
Plasma cells
Memory B
Helper T (Th2)
What cell is important in autoimmune diseases?
Regulatory T
The ability to carry out immune responses if properly stimulated
Immunocompetence
Antibody effect
Phagocytosis
Lysis / Inflammation (activation of complement)
Agglutination
Neutralize (immobilization of pathogen)
5 different classes of antibodies and what it stands for
IgG
IgA
IgM
IgE
IgD
Immunoglobulin __
IgG
chronic (long term)
IgM
acute (immediate)
IgA
mucous membrane
IgE
allergies and parasites
APC
- monocytes (macrophage)
- B cell
- Dendritic cella
IL-4 does not come from
Antigen Presenting Cells (APC)- outside
