exam_1_20150304202940 Flashcards
Etiology
Cause
Pathogenesis
sequence of cellular or tissue events in response to the etiologic agent, from initial stimulus to the ultimate expression of the disease
morphologic changes
structural alterations in cells and organs of the body that characterize the disease or are diagnostic of the etiologic process
clinical significance
functional consequences of the morphologic changes
Cell Adaptations
hypertrophy: increase in size (Myocardial fibers)atrophy: shrink or decrease in sizehyperplasia: increase in number of cells/increased rate of cellular divisionMetaplasia: reversible change in which one adult cell type is replaced by another adult cell type (can result in neoplasia)
Cell Injury cause and types
Causes: hypoxia, physical or chemical agents and drugs, infectious agents, immunological reactions, genetic defects, nutritional imbalance, agingTypes: metaplasia (reversible)(irreversible): disturbance in cell membrane and cell wall, mitochondrial dysfunction
What happens to the cell when it is injured and dies?
-ATP depletion-decreased ATP synthesis anaerobic metabolism and acidosis -number of Na/K pumps decrease more Na in cell pulls more water-dilation of ER causes decreased protein synthesis -accumulation of free radicals with not enough antioxidants-Ca influxes which causes more damage and can cause cell death/catabalize cell membrane-Mitochondrial damage and loss of membrane integrity results in cell death -apoptosis (cell eats self)
What are the two types of cell death?
Necrosis:-abnormal and not regulated-loss of membrane integrity-stimulates inflammation (increase leukocytes triggers lysosomes to release enzymes for digestion of cell substances)Apoptosis:-normal and regulated (can become abnormal in disease)-physiological (cell no longer needed) or pathological (cell is threat)-contents of cell shrink, membrane remains intact and does not stimulate inflammation
What are free radicals?
chemicals that have a single unpaired electron in outer orbit (unstable!)produced during mitochondrial respirationcause cell damage by reacting with nucleic acids, and other cellular proteins and lipids
What are the two types of oxygen derived free radicals?
- Reactive Oxygen Intermediates (ROS)types: O2 superoxide H2O2 hydrogen peroxideOH hydroxyl radical produced in phagocytic leukocytes and mainly macrophages and neutrophils 2. Nitric oxide Intermediates (NOS)produced by leukocytes and other cellstypes: physiological {endothelial (eNOS), neuronal (nNOS),}non-physiological {inducible (iNOS)}
What free radical causes the most damage?
OH hydroxyl radical
What regulates free radicals?
Antioxidants (physiological substances that protect the body against damage from chemical reactions caused by free radicals)Function: bind to and break down free radicals by enzymesblock formationbind to ions to take free radicals away and out of cellrepair damage they cause in cell
Types of Antioxidants
catalase (enzyme from perioxisomes organelle)superoxide dismutase (SOD)gluthione peroxidase (GSH)CoQ10Vitamin E, A, C, and Beta-CaroteneSynthetic Ones (dopamine and other meds)
What is oxidative stress?
When the balance between free radicals and antioxidants is off and there is more free radicals than antioxidants.
Which NOS is the problem/causes damage?
iNOS is induced by inflammatory cytokines and responsible for production of NO in inflammatory reactions; also critical for wound healing
What is the role of the three NOS?
vascular smooth muscle relaxation, vasodilationantagonizes platelet activationdecreases leukocyte recruitmentmicrobicidal agent
Where do all blood cells reside?
stem cell pool, bone marrow pool, and peripheral blood pool
What does thrombopoieten do?
peptide produced by liver, kidneys, skeletal muscle, and marrow stoma responsible for clotting factors and platelet production
The myeloid stem cells differentiate into…
interluekins, erythrocytes, thrombocytes, monocytes, myelocyte (granulocyte: neutrophils, eosinophils, basophils)
What cells differentiate from lymphoid stem cells?
plasma cell, NK cells, T cells, B cells
What are the types of leukocytes?
- monocytes (immature) produced in bone marrowmature to macrophages in tissuethey are the FRONT LINE because they are already there and they are more efficient than neutrophils (they can phagocytize up to a 100 before they die)replicate in tissuesecrete inflammatory metabolites and cytokinesare antigen presenting cells to activate T and B cells2. Neutrophilsmature in bone marrow (mature-segs/immature-band cells)LARGEST IN CIRCULATIONdigest 3-20 before dying release cytokines and facilitate inflammation3. eosinophils (destroy parasites, involved in allergic responses)4. basophils (release histamine, leukotrienes, prostaglandins and platelet activating factor in inflammation; have IgE receptors and bind to IgE antibody; ALLERGY)
What are the types of lymphocytes?
- T cells (most abundant)originate in bone marrow&mature within the thymusreside in the T cell zones of lymphoid tissue and spleenTypes: T helper, T cytotoxic, T suppresser, MEMORY cells2. B cellsmature in bone marrow and reside in lymph nodes of cortex and medulla and spleen B zonesantigen receptors on surface: IgM and IgD Types: plasma cell and MEMORY 3. NK cellstarget virus, malignant, and other mutant cellssecrete cytokines to activate macrophages and T cellsNO MEMORY
How many antigens can a T cell react with?
one
What is a plasma cell?
a B cell that has been activated to secrete antibodies (immunoglobulins IgG, A, E)