chapter 13 Flashcards
what is the Immune System’s purpose
- recognizes foreign material
- protects the body from anything that is not a part of the body
what are the 3 lines of defense
- external barriers
- cellular and chemical components
- to target specific pathogens
how is skin a line of defense
- physical barrier
- resident microorganisms
- acidic pH and fatty acid content of sweat
how are mucous membranes a line of defence
- cilia and mucus in respiratory system
- acidity of stomach
- fluids such as tears, saliva, and urine
how does the spleen form a line of defense
- white pulp has immunological functions:
phagocytic cells react to antigens in bloodstream - macrophages in red pulp remove worn, damaged
blood cells
how is the lymphatic system part of a line of defense
responsible for collecting and returning excess
interstitial tissue fluid to cardiovascular system
major lymph nodes
⚪ submandibular
⚪ prescapular
⚪ axillary
⚪ inguinal
⚪ popliteal
what is Mucosa-Associated Lymphatic Tissue (MALT)
⚫clusters of lymphoid tissue in various areas
throughout the animal’s body
⚫located near mucosal surfaces: CALT, NALT, and GALT
⚫not encapsulated like a lymph node
⚫function:
-identify antigens, mount immune response
are tonsils part of
MALT
yes
what are peyer’s patches
⚫aggregations of lymphoid in small intestine
⚪ cattle, sheep, pigs, horses, dogs
what type of WBC are found in the thymus
T lymphocytes
what do T lymphocytes do
⚪ programmed to fight specific antigens
⚪ produced throughout life of the animal
is the innate immune system specific
no
what types of barriers does the innate immune system have
provides anatomical
and cellular barriers
what anatomical barriers are on surface of body
- keratinized epithelial tissue of skin
- mucous membranes
line respiratory, digestive, urinary, and reproductive systems - tears, saliva, and nasal discharge production
- acidic environment of the stomach
what is the second line of defense
when a pathogen
makes its way past
physical barriers,
the body controls
spread of infection
through acute
inflammation
what is a fever
a systemic inflammation response where chemical
mediators are carried throughout the body
what cells can do phagocytosis
neutrophils, monocytes, macrophages, dendrite cells
what are the 5 steps of phagoocytosis
activation and
chemotaxis
attachment
ingestion
destruction
exocytosis
what is compliment cascade
when one complement
protein is activated, it
activates the next
complement protein in the
series final result is
antigen cell lysis, or body cell apoptosis
what are the 3 types of cytokines
⚪ interleukins
⚪ interferons
⚪ chemokines
what are cytokines
- attract immune cells to specific site
- act as inhibitor molecules
- enhance the immune processes
- play a major role in hematopoiesis
interleukin actions
promotes inflammation
affects metabolism
kills cells
affects leukocytes
affects cell growth
affects blood flow
affects metalbolism
affects the brain
what are natural killer cells (NK)
- found in blood and lymph
- part of both innate and
adaptive immune systems - do not ingest target cell
- bind to cell to induce cellular changes leading
to apoptosis
what are the 2 types of receptors on NK cell membranes
- killer inhibitory receptor (KIR)
- killer-activating receptor (KAR)
what is Adaptive
Acquired Immunity
B lymphocytes and T lymphocytes are programmed to remember and to respond only to specific pathogens
B Lymphocytes characteristics
- formed in the bone marrow
- programmed to secrete a specific antibody
immunoglobulin (Ig) - migrate to lymph nodes and spleen
- precursors are the thymocytes
- enter bloodstream as T cells
what are Memory Cells
- clones of T cells and B cells that have been activated in an immune response
- stay in lymph nodes or circulate in blood
IgM characteristics
- the largest antibody
- temporary
- produced when animal
is first exposed to an
antigen
IgG characteristics
- smallest and most common
- produced and released by plasma cells bacterial and viral infections
- indicative of a chronic
infection - can produce passive
immunity to fetus
IgA characteristics
- protects body surfaces from foreign substances
mucosal surfaces (intestinal tract and lungs)
IgE characterisitics
- binds to allergens and triggers histamine release
from mast cells and basophils - protects against parasitic helminth infections
IgD characteristics
activates basophils and mast cells
what is cell mediated immunity
- controlled by T cells
- does not depend on antibody production
- provides immunity against intracellular pathogens
- T cells attach directly to antigen markers on surfaces of phagocytes that have already processed the pathogen
- cannot recognize antigens on their own
- first stimulated by APC cell
what Cells Formed from Sensitized T Cells
- memory cells
- helper cells (TH )
- help immune system by secreting cytokines - cytotoxic T cells (TC)
- also known as effector cells, killer cells, killer T cells
- attach to antigenic markers on cells and destroy those cells - regulatory T cells (TS)
- inhibit helper T cell and cytotoxic T cell function
- prevent B cells from transforming into plasma cells
what is active immunity
the result of an active immune process
⚪ natural immunity
⚪ vaccines: modified live (attenuated), killed virus
what is passive immunity
- receiving antibodies from an external source
⚪maternal antibodies
across the placenta via colostrum - offers protection
⚪ no activation of immune system - protection lost once antibodies disappear from the animal’s system
what are Factors in Determining Likelihood of Disease
1 exposure
2 mode of infection/transmission
3 virulence
4 immune system strength
5 resistance
⚪ acquired resistance
exposure or vaccination
⚪ species resistance
what is Hypersensitivity Reaction
an overreaction of the immune system
what is hypersensitivity type 1
- animal is sensitized
- antigens bind to IgE antibodies
- second exposure to same antigen is severe
- fatal without immediate medical intervention
what is type 2 hypersensitivity
- occurs when infection is present
- immune system is cause of the disease, rather than the cure
- cross-reactive antibodies form
- body’s own cells are destroyed
what is type 3 hypersensitivity
- antibody and antigen form an immune complex
- trapped in small blood vessels
- activated complement cascade sends chemicals to site
- tissue is damaged
what is type 4 hypersensitivity
- cell-mediated reactions
- systemic inflammatory response syndrome (SIRS)
