Immunology Flashcards
What are the functions of the lymphatic system?
to scree the interstitial fluid for pathogens in area of your body most likely to get infected
It aids in the absorption of dietary fats and vitamins from the digestive system
what is lymph?
The fluid of the lymphatic system
how is lymph made?
from the plasma that leaves the cardiovascular system and enters the tissues that becomes interstitial fluid, about 20% of the remaining IF enters lymphatic capillaries as lymph
Where does lymph go?
lymph gets delivered to lymphatic capillaries nodes through lymphatic vessels
describe lymphatic capillaries and their function
the smallest of the lymphatic vessels and the origin of lymph flow
describe red bone marrow and the function
the site of production and differentiation of many formed elements of the blood.
It is the primary lymphoid organ, a site where lymphocytes mature and proliferate
describe the thymus and its function
a bi lobed, h shaped glandular organ, located just above the heart, surrounded by a fibrous capsule of CT
A primary lymphoid organ, a site where lymphocytes mature and proliferate
describe lymph nodes and their function
bean shaped organs found associated with the lymphatic vessels
Houses many leukocytes that bind foreign particles present in the lymph and initiate an immune response
describe the spleen and its function
primarily responsible for filtering blood, it is often considered the body’s largest lymph node
describe the tonsils and their function
lymphoid nodules associated with the nasopharynx
Describe mucosa- associated lymphoid tissue (MALT) and the function
Lymphoid tissue associated with the digestive tract and respiratory system
describe lacteals and the function
specialized lymphatic capillaries associated with the gut
They absorb bile and lipids from the digestive tract
Why are the bone marrow and thymus considered primary lymphoid organs?
they are both involved in leukocyte development
What is innate immunity?
the processes you are born with that provide resistance to pathogens entering, binding, and causing disease to the body
What are the first lines of defense in innate immunity?
skin and mucous membranes
How do skin and mucous membranes work?
These boundaries contain chemical substances that resist pathogens adherence and propagation
What are the second lines of defense in innate immunity?
PAMPs, DAMPs, PRRs, the cells of innate immunity
How do Pathogen associated molecular patterns (PAMPs) work?
They are molecular patterns on pathogens your innate immune system can recognize.
Lipopolysaccharide (LPS)
Peptidoglycan
How does Damage associated molecular patterns (DAMPs) work?
damaged tissue may elicit these molecular patterns that your innate immune cell receptors can bind to.
How do pattern recognition receptors (PRRs) work?
the receptors on innate immune cells that bind PAMPs and DAMPs
What are the cells of innate immunity?
neutrophil, eosinophil, basophil
Explain phagocytosis
the process of cells engulfing other cells, bacteria, or debris
What cells perform phagocytosis?
neutrophils, macrophages, and dendritic cells
Describe the 4 phases of inflammation
- Tissue injury causing inflammatory chemical release
- Vasodilation
- Increased vascular permeability
- Phagocyte mobilization
What Is the function of histamine in the inflammation process?
histamine promotes vasodilation, bronchoconstriction, smooth muscle contraction, increased secretion, and mucus production
What is complement?
a cascade of events initiated by either the classical, alternative or lectin pathways
How is complement activated?
it begins with several proteins becoming activated by enzymatic fragmentation in the presence of a pathogen
What does the complement process ultimately lead to?
the destruction of bacteria, enhanced inflammation, and mobilization of leukocytes
describe fever
increased body temperature, part of a normal innate immune response
How is a fever triggered?
pathogens and leukocytes release pyrogens (chemicals that signal the hypothalamus to increase body temperature) that signal the hypothalamus to raise body temperature
How is fever helpful?
fevers inhibit the production of viruses and bacteria, increasing the metabolic rate of your cels, and enhance the actions of immune system protein such as interferons and some enzymes
Explain extra action (diapedesis) of leukocytes
leukocytes stop completely and squeeze through the clefts between endothelial cells
What is adaptive immunity?
designed to recognize self from non self, it mounts reactions that are specific to the particular substance or pathogen presented. The cells and chemical factors involved in adaptive immunity come into play when first and second line defenses fail
What is an antigen?
any substance that causes antibody formation, also known as immunogen
Describe major histocompatibility complex
a gene cluster whose proteins present antigens to T cells
There are 2 distinct membrane bound proteins that play roles in antigen presentation
What is antibody mediated immunity?
also known as humoral immunity. Primarily involves B cells and neutralizes threats outside human cells
How are antibodies produced?
Produced by plasma cels which are differentiated B cells
-B cells become activated, proliferate, and differentiate into plasma cells that secrete large quantities of antibodies
Describe antibody structure
Y shaped molecule made up of 2 heavy chains and 2 light chains
The Fc region determines the antibody class and function
Describe immunological memory
the first time you are exposed to an antigen, long lived memory lymphocytes are generated providing an army of defense in case you are exposed to the same or similar pathogen again, this is the primary adaptive response, the secondary adaptive response occurs upon reexposure
describe clonal selection
when a B cell or T cell binds its specific antigen, it is selected for activation
Describe clonal expansion
the selected cell proliferates, creating clones that are identical and specific to the same antigen. some of these clones differentiate into effector cells while others become memory cells
What is cell mediated immunity?
Adaptive immunity
activated by helper T cell subclass Th1
What cells carry out cell-mediated immunity?
cytotoxic T cells:
-CD8-TC
Describe helper T cells and their function
Also known as CD4+
-or
What do antibodies do?
-Neutralization
-Opsonization
-Agglutination
-Activation of complement
-Antibody dependent cell mediated cytotoxicity
