Exam 7 (Musculoskeletal and Immunology) Flashcards
Immunology
Study of rxns of host’s immune system when foreign substance introduced (immune response)
Antigens
Foreign substance that causes immune response
Epitope
Part of antigen body recognizes and antibodies attach.
Immunity
Resistance to infection
Immunization
Exposure to antigens which are foreign
Passive immunity
Natural
Breast milk, placenta Ab transport
Or artificial
Ab in form of injection (gamma globulin)
Innate immunity
Not specific
No memory
Active immunity
Occurs through process of making Ab in response to presence of antigen in system
Specific
Takes 1-2 weeks to start
Uses T and B cells
Humoral immunity
Antibody mediated
Major defense for bacterial infection
Uses B Cells (plasma)
Cellular Immunity
Cell mediated
Uses T cells
Cytotoxic T cells destroy cells with antigen that activated them by putting in perforins causing apoptosis
Immunoglobulin structure
2 heavy chain
2 light chain
Held together by noncovalent forces.
Disulfide bridges between chains
IgM
First immunoglobulin made in acute infection
On naive B cells
IgG
Made in chronic (long) exposure to antigen
4 subclasses
Secondary responses
Long life span
Monomer
Mostly secreted (into blood)
Good at opsonization and activating complement
Cross placenta to protect fetus
Opsonization
Marking cells for destruction
Fc fragment
Opsonization
Complement fixation
Fab fragment
Binds to antigen
C terminus
End of Fc portion
N terminus
End of Fab portion
Isotype
Unique amino acid sequence common to all immunoglobulin of a given class
Allotype
Slight generic variation of Ig sequences in membrers of species
IgD
Expressed on naïve B cells.
Synthesis ends with activation
Membrane bound (not much secreted) so we don’t test blood for it
Monomer
IgA
Appears later in responses
2 subclasses
Monomer (IgA1) or dimer (IgA2)
Dimer secreted through breastmilk, tears, saliva, mucous through specialized epithelial cells
IgE
Appears later in responses
Monomer
Bound to mast cells (not in serum)
Allergic/inflammatory responses
BCR
B cell receptor
Immunoglobulin or antibody
Surface bound or secreted
TCR
T cell receptor
Alpha and beta chains or gama and delta chains
ONLY surface bound
Pro-B cells
Undergo gene rearrangement for antibody heavy chain production.
Then mu heavy chains produced in cell cytoplasm
Pre-B cells
Mu heavy chains get surrogate light chains making a pre-B cell receptor,
only cells with this receptor survive past this point
Lasts two days
Several divisions
Gene rearrangemen occurs for light chain production
Immature B cells
Complete IgM molecules on cell surface.
No more M chains in cytoplasm
Committed to produce specific antibody
Cells that make antibodies to self-antigen undergo apoptosis
Mature B cells
Express IgD and IgM of same specificity expressed on surface.
IgD is cell marker
IgM is more functional
Live only a few days if unstimulated
Stimulated cells undergo another phase to form specific memory or plasma cells
Plasma cells
Most fully differentiated lymphocyte
Main function is antibody production
Located in germinal centers and in bone marrow
T-cell development stages
Prothymocyte
Double-negative thymocyte
Double-positive thymocyte
Mature T cell
B-cell development stages
Pro-B cell
Pre-B cell
Immature B cell
Mature B cell
When does T cell development begin
pro-thymocytes committed to becoming T cells travel to thymus.
Mature from traveling from outer cortex into inner madulla of thymus
Double negative thymocytes
Negative for CD4 and CD8
Gene rearrangement of TCR heavy chain
Appearance of functional beta chain causes it to become positive for CD4 and CD8
Double-positive thymocytes
T-cells positive for both CD4 and CD8
Gene rearrangement occurs and once TCR complete positive selection takes place.
Cells that can’t recognize MCH undergo apotosis.
If bind to MHC I become CD8
If bind to MHC II become CD4
Negative selectoin
Occurs in corticomedullary junction
Cells exposed to self peptides bound to MHC molecules.
Those that are activated undergo apoptosis.
Unactivated goes into peripheral blood
CD4+ T cells
2/3 of T cells
Helper T cells
Recognize antigen with MHC II
CD8+ T cells
1/3 of T cells
Cytotoxic T cells
Recognize MHC I
How long do resting T cells live
Several years in lymphoid organ
Mechanical barriers
Epithelium
Directional air/fluid flow
Mucus
Cilia
Chemical barrier
Enzymes
pH
Fatty acids/Microcidal molecules
Biological barriers
Commensal microbes (normal flora)
Granulocytes
Most common WBCs
Neutrophils
Eosinophils
Basophils
Monocytes
Cytoplasmic granulocytes.
Can do surface adhesion to find intracellular opening.
Diapedesis
Diapedesis
Granulocytes ability to enter cell gaps
Eosinophil
Granulocyte
Releases proteins, cytokines, chemokines to trigger inflammatory response.
Used in parasitic infections and allergic reactions
Basophil
Least common granulocyte
Induce and regulate hypersensitivity reactions.
Resemble mast cells
Release histamine in response to IgE.
Attracted to prostaglandin D2 from mast cell
Mast cell
Granulated.
Proteoglycan, histamine, proteases in granulocytes.
nflammatory intiiated by IgE and igG and TNF-alpha in response to bacteria.
Respond in seconds to minutes.
Leukotrienes, prostaglandins, platelet activating factors produced after degranulation
Monocyte
Granulocyte
Baby macrophage
Phagocytosis
Multinucleated
Kupffer cells in liver
Microglia
Macrophage
Phagocytosis
Tumor activity
Kill intracellular parasites
Secretes cell mediators
APC
Pathogen recognition receptors
Toll like receptors
Dendritic cells
Most potent phagocytotic cells
APC
Pathogen recognition receptors
Toll like receptors
Natural killer cells
Large granulated circulating
Innate immunity
Targets cells missing MHC I to induce apoptosis
Primary lymphoid organs
Where lymphocytes are made
Thymus (T-cells)
Bone marrow (B-cells)
Secondary lymphoid organs
Spleen
Lymph nodes
Tonsils
Apendix
Peyer’s patches
Mucosal associated lymphoid tissue (MALT)
Where is antigen dependent lymphocyte reproduction
Secondary lymphiod tissue
Where is antigen independent lymphocyte reproduction
Primary lymphoid tissue
Spleen
Largest secondary lymphoid organ
Upper left abdominal quadrant
Filters old cells, damaged cells, and foreign antigens from blood.
Lymph
Colorless fluid
Enters thin-walled vessels from interstitial spaces between tissue cells
Filtered by lymph nodes
Lymphadenopathy
Enlargement of lymph node.
Antigen contact is made.
Lyymphocyte traffic stopped to immobilized antigen.
Increased number of lymphocytes recirculated
Classical complement pathway
Triggered by immune response
Antibodies needed
Mannose binding lectin complement pathway
Lectin binds to mannose groups of bacteria
Alternative complement pathway
From viruses, bacteria, tumor, fungus
Main factor of complement pathway
Cell lysis
What do proteins made during complement pathway do
Opsonization
Chemotaxis
Cell lysis
Activate B cells
Discard debris from apoptosis
Cytokines
Chemical messengers made by stimulated cells.
Affect activity of other cells
Local mediators of immune response
Bind to specific protein receptors on target cells.
Some are growth factors
Interleukin 1
Cytokine
Produced by macrophages
Stimualtes bone marrow to make more neutrophils
Interleukin-6
Cytokine
Endogenous pyrogen (causes fever)
Acts on liver to make acute phase reactants (APR)
Interleukin-8
Cytokine
Recruits neutrophils to site of infection
Tumor necrosis factor alpha
Cytokine
Endogenous pyrogen (causes fever)
Recruits neutrophils to site of infection
Acute phase reactants (APRs)
Proteins made by liver and found in serum.
Quickly increases by at least 25% due to infection or trauma.
Liver increases production in response to cytokines from monocytes and macrophages
APR examples
C-reactive protein
Haptoglobin
Fibrinogen
and more
C reactive protein
APR
Most widely used indicator of acute inflammation because of rapid rise and decline.
Increased levels are significant risk factor for MI and stroke
Serum amyloid A
APR
Causes adhesion and chemotaxis of lymphs and phagocytic cells.
Contributes cleaning of inflammation
Increased levels show risk of atherosclerosis
Mannose binding protein
APR
Recognizes and binds to mannose and other sugars found on bacteria, viruses, yeasts, and parasites
Promotes phagocytosis.
Activates complement
Fibrinogen
APR
Promotes coagulation at site of injury
Acts as precursory to fibrin in coagulation cascade
Bridges platelets to assist in adhesion
Alpha-2 antitrypsin
APR
Acts to clean up effects of neutrophil invasion during inflammatory response.
Protease inhibitor.
Protects elastin in lungs from elastase released from granules in neutrophils.
Deficiency causes emphysema
Ceruplasmin
APR
Principal copper-transporting protein in human plasma.
Scavenger of superoxide radicals made by phagocytes.
Deficiency causes Wilson’s disease (Kayser Fleisher rings in eyes)
Calor
Heat in inflammation
Rubor
Redness, erythema in inflammation from increased blood flow (hyperemia).
Mediated by prostacyclin and nitric oxide
Tumor
Edema or swelling in inflammation.
Vascular permeability causes movement of fluid and protein into tisssue
Dolor
Pain in inflammation
Nitric oxide
Major componenent of vasodilation in inflammation
Serous
Few cells
Serosanguineous
Red cells
Fibrinous
Containing fibrin
Purulent
Having white cells (pus)
Prostaglandins
Released from mast cells
Neuronal stimulation causes pain
Platelet activating factor
Released from mast cells
Potent platelet aggregator
Vasodilator
Platelets
Derived from megakaryocytes of bone marrow.
Stor serotonin in dense granules used to mediate aggregation and recruitment of neutrophils.
Induce vasoconstriction but in cerebral arterioles causes vasodilation.
Aggregated by TXa2
Prostanoids
Prostaglandins and thromboxane A2
Made by COX
Nitric oxide
Made by L-Argininie through action of NO synthetases.
nNOS in neuronal
eNOS in endothelial
iNOS in inducible
Used in inflammation
Stages of tissue repair
Hemostatic
Inflammation
Proliferative
Angiogenesis
Reepithelization
Remodeling
Hemostatic phase of tissue repair
Fibrin and fibronectin provide beginning matrix that acts as initial substrate for inward micration of Mø then fibroblasts, keratinocytes, and endothelial cells.
THrombin causes release proinlfammatory cytokines.
Plateletts in provisional matrix are rich source of chemotatic factors and cytokines.
Inflammatory phase of tissue repair
Neutrophils appear and udnergo apoptosis and macrophages clear.
Contributes to scab formation.
Proliferative phase of tissue repair
Formation of granulation tissue.
Replaces provisional matrix.
Angiogenesis starts
Angiogenesis phase fo tissue repair
Production of new capillaries from other vessels activated by TNF alpha and VEGF secretion from M2 macrophages.
Activated by low oxygen, high lactate, low tissue pH
New capillaries remain leaky for healing
Re-epithelialization phase
Continued formation of granulation creates surface with re-epithelialized tissue at wound edges.
Continues to move toward center
Type-1 allergic reaction
Immediate response
Production of IgE
Onset within 15-30 mins
Systemic reactions against peanut or bee venom antigens can cause anaphylaxes.
Allergic asthma
Type II allergic reaction
Antibody mediated cytotoxic
IgG IgM Complement
NKC, Eosinophils, neutrophils, macrophages
Onset in 5-8 hours.
Immunization to erythrocyte antigens during pregnancy (mom is Rh - baby is Rh +) Mom makes antibodies against Rh and kills baby
Type III allergic reaction
Immune complex medicated reactions
Mediated by antibody formed during immune response.
When not cleared it will setlle in tissues.
Type IV allergic reaction
Delayed hypersensitivity reaction
T-cell mediated
T helper cells secrete cytokines which activate macrphages and cytotoxic T clels.
Onset is 2-3 days.
Poison ivy.
TB Skin test
Antibody mediated autoimmune disease
Majority of autoimmune diseases
IgG1 and IgG3 cause most of them by inducing complement-dependent damage attack on tissues.
IgG4 causes pemphigus.
What gender has most of the autoimmune diseases
Females (90%)
Estrogen thought to effect B-Cells
This thought supported by SLE appearance in preg
Secondary immunodeficiencies
More common than primary (genetic)
Resulted from factors that affected host with intrinsically normal immune system (drugs, disease, environment)
Most common is malnutrition
Organic component of bone
Collagen for flexibility
Ground substance made of glycoproteins, proteoglycans, and glycosaminoglycans fills around collagen and hydroxyapatite crystals
Inorganic component of bone
Hyoxyapatite made of calcium phosphate and and calcium carbonate.
Hardness and strength.
Axial skeleton
Skull
Vertebral column
Rib cage
Protects vital organs
Appendicular skeleton
Arms
Legs
Pelvis
Shoulder
Movement, blood cell production, mineral storage
Cortical/compact bone
Outer layer.
Thick, dense
Protection and strength.
Bone cells in lacunae
Nutrition from Haversian canals
80% of bone in the body
Trabecular/spongy bone
INside cortical bone
Metabolic unction
THin, porous.
Bone marrow
Composed of spicules sor plate.
20% of bone in body
Haversian cannals.
Contain blood vessels and nerve fibers.
Lamellae
Around haversian canals
Parathyroid hormone
Accelerates bone resporption
Osteoblast
Synthesize bone.
Come from osteoprogenitor cells
Osteocytes
Inactivated osteoblasts trapped in the bone they formed
Osteoclasts
Break down bone (resorption)
From monocyte cell line.
Multinucleated
Bone fracture repair order
Fracture hematoma forms
Fibrocartilaginous (soft) callus forms
Hard (bony callus forms
Bone is remodeled
Bone turnover
Balance of activity of osteoblast and osteoclasts
Why does bone resorption occur.
To release calcium and other ions into blood.
Remove old bone pieves to allow newer, better bone to form.
How does resorption occur
THrough secretion of acid and proteolytic enzymes that digest bone