HLTH module 3: immunity Flashcards
structures of the lymphatic system
lymph nodes, spleen, tonsils, intestinal lymphoid tissue, and lymphatic circulation
what does the immune system consist of?
the lymphoid structures, immune cells, tissues concerned with immune cell development, and chemical mediators
what structures remove foreign materials
lymphocytes and macrophages
what structures produce and develop immune cells?
the bone marrow and the thymus; all cells originate in the bone marrow and the thymus is significant during fetal development
role of thymus in immune cells
it programs the immune cells to ignore self-antigens
chemical mediators
include chemicals such as histamines and interleukins that can play a role in the immune reaction
anitgen
a foreign substance that stimulates immune response
antibody
specific protein produced in the humoral response to bind with an antigen
autoantibody
antibodies against self-antigens; body attacks itself
function of neutrophils
phagocytosis
function of basophils
releases histamine during anaphlylaxis
eosinophils
participate in allergic reactions and are defence against parasites
monocytes
migrate from the bloodstream to become macrophages
B lymphocytes
humoral immunity-activated cell that becomes an anti-body producing plasma cell or a B memory cell
what are T lymphocytes involved in?
cell-mediated immunity
memory T cells
remember antigen and quickly stimulate an immune response
helper T cells
activate B and T cells to control or limit specific immune responses
complement proteins
group of inactive proteins in the circulation that, when activated, stimulate the release of other chemical mediators, promoting inflammation, chemotaxis, and phagocytosis
prostaglandins
group of lipids with varying effects; some cause inflammation, vasodilation, and increased permeability
leukotrienes
group of lipids, derived from mast cells and basophils; causes contraction of bronchiolar smooth muscle and have a role in inflammation
cytokine examples
lymphokines, monokines, interferons, and interleukins
cytokines
produced by macrophages and activated T lymphocytes; stimulate activation and proliferation of B and T cells, communication between cells, and are involved in inflammation, fever, and leukocytosis
chemotactic factors
attract phagocytes to area of inflammation
what are antigens composed of?
usually a combination of complex proteins or polysaccharides, or glycoproteins
what are specific antibodies produced by?
B lymphocytes
major histocompatibility complex
antigen molecules present in genes (chromosome 6); has an essential role in activation and regulation of the immune response
autoimmune diseases
occur when the immune system no longer recognizes self from non-self and begins to attack its own cells and structures
mononuclear phagocytic system
occurs when monocytes develop into macrophages
where are macrophages present?
the liver, lungs, and lymph nodes
what occurs after macrophages engulf materials?
they display the antigens on their cell membranes, allowing the lymphocytes to respond to this display and initiate the immune response
what do macrophages secrete?
monokines and interleukins
primary cell in the immune response
the lymphocyte
where do T lymphocytes develop from?
stem cells held in the thymus
what type of immunity are T lymphocytes involved in?
cell-mediated
what do T lymphocytes do?
recognize antigens and create an army of more T and B lymphocytes to attack the invader
two subgroups of T cells
CD4 (helper) and CD8 (killer)
what secretes cytokines?
T lymphocytes
B lymphocytes role
produce antibodies
where do B lymphocytes come from?
the bone marrow then proceed to the spleen and lymphoid tissue
natural killer cells
destroy tumor cells and virus cells without any prior exposure and sensitization
another name for antibodies
immunoglobulins
anatomy of antibodies
each has a unique sequence of amino acids attached to a common base
how do antibodies destroy antigens?
they bind to a specific matching antigen and through this, destroy it
where are antibodies found?
the general circulation
5 classes of antibodies
IgG, IgM, IgA, IgE, and IgD
most common antibody in the blood
IgG
how is the complement system activated?
when an anitgen-antibody complex binds to the first complement component (C1), a sequence of activating steps will occur
result of the complement system?
destruction of the antigen by lysis
two steps of the immune response
primary response (first exposure to the antigen) and secondary response (repeat exposure to the same antigen_
4 types of acquired immunity
natural active, artificial active, natural passive, and artificial passive
natural active immunity
acquired by direct exposure to an antigen
activate artificial immunity
develops when a specific antigen is purposefully introduced into the body, stimulating the production of antibodies; ex. viruses
passive immuntiy
occurs when antibodies are transferred from one person to another
passive natural immunity
occurs when IgG is transferred from mother to fetus across the placenta or through breast milk; protects the infant for the first few months of life
passive artificial immunity
results from the injection of antibodies from a person or animal into a second person; ex. rabies antiserum or snake antivenom
herd immunity
a phenomenon in which a high percentage of the population is vaccinated or has experienced a prior infection of the disease, thus decreasing the chances of spreading the disease
examples of autoimmune diseases
hashimoto thyroiditis, systemic lupus erythematosus, rheumatic fever, pernicious anemia, and hyperthyroidism
what occurs in autoimmune reactions?
inflammation and tissue necrosis due to self-antigens not being recognized
systemic lupus erythematosus
a chronic inflammatory autoimmune disease that affects a number of systems, creating a facial rash around the nose and cheeks
discoid lupus erythematosus
a less serious version of SLE affecting only the skin
who does SLE primarily affect?
women aged 10-50, higher in black, natives, asian, and hispanic individuals
cause of SLE
not established but appears to be a combination of genetic, hormonal (estrogen levels), and environmental factors (UV light)
what is SLE characterised by?
the presence of large number of circulating autoantibodies against DNA, platelets, RBCs, nucleic acid, and other cellular materials such as antinuclear antibodies
why does skin inflammation occur in SLE?
due to immune complexes (especially those with anti-DNA antibodies) are deposited in CT’s, activating the complement system, inflammation, and tissue necrosis
vasculitis
inflammation of the blood vessels and this occurs in SLE; also causes ischemia to cells, causing tissue necrosis
common sites for vasculitis in SLE individuals
the kidneys, lungs, heart, brain, skin, joints, and GI tract
diagnosis for SLE
vasculitis impacting at least four body areas
clinical signs for SLE
skin rash and joint inflammation are initial symptoms which progress to kidney and lung involvement; later symptoms include chest pain, depression, anemia, hair loss, and oral ulcers
diagnosis for SLE
looks for the presence of antinuclear antibodies in blood serum, as well as lupus erythematosus cells which are mature neutrophils containing nuclear materials; low RBC, leukocyte, lymphocytes, and platelets are also common
SLE treatment
often treated by a rheumatologist and glucocorticoids and NSAIDS are often used to treat the inflammation and decrease the immune response
how to prevent SLE flare ups?
avoidance of sun and excessive fatigue
