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Topic 1, Introduction to Clinical Dentistry - Coggle Diagram
Topic 1
Pathological stimuli causing cell changes
Oxygen depriviation
Physical Agents
Chemical Agents & Drugs
Infectious Agents
Immunologic Reactions
Genetic Abnormalities
Nutritional Imbalances
Disorders due to disturbances in body fluid flow, electrolytes and blood
Edema
Hemorrhage
Thrombosis
Embolism
Infarction
Shock
Condition of tissue to have normal function
Good blood circulation
balance between body fluids, intra and extravascular
Concentration of substances in fluids that remain
cell adaptation to permanent stimuli
Hypertrophy
increase in the affected organ size due to increase in the size of the cells.
Pathologic hypertrophy: striated muscle cells in the heart and skeletal muscles have only a limited capacity for division, and respond to increased metabolic demands mainly by undergoing hypertrophy
Physiologic hypertrophy: physiologic growth of the uterus during pregnancy results from hypertrophy of smooth muscle fibres
Atrophy
reduction in the size of an organ or tissue because of a reduction in cell size and number
Reduced trophic signals (such as those produced by growth receptors), which promote nutrient uptake and increase mRNA translation, lead to a decrease in protein synthesis.
Apoptosis
Apoptopic pathways
Intrinsic/Mitochondrial Pathway
Extrinsic/Death receptor pathway
Initiation stage
Execution stage
Removal of Dead Cells
Apoptosis vs Necrosis
Apoptosis
Natural process
organelles still functional
no symptoms
can be beneficial
treatment not required
no energy needed
Necrosis
due to external agents
organelles not functional
inflammation
harmful
requires treatment
requires energy
Pigmentation found in oral cavity
Endogenous
Haemoglobin
blue. red, purple
Hempsiderin
brown
Melanin
Brown, black, or gray
Exogenous
silver amalgam
gray, black
graphite
gray, black
lead, mercury, bismuth
gray
Chromogenic bacteria
brown, green black
Cell Adaptation to strong stimuli/sensitive cells
Metaplasia
one differentiated cell type (epithelial or mesenchymal) is replaced by another cell type due to the response from a sensitive cell
metaplastic change is stimulated by signals generated by cytokines, growth factors, and extracellular matrix components in the cells’ environment
Direct link between transcription factor dysregulation and metaplasia is seen with vitamin A (retinoic acid) deficiency or excess
Example case
Epithelial Metaplasia (columnar to squamous) in respiratory tract
cell adaptation to stimuli that change cell type/cell differentiation
Hyperplasia
increase in the number of cells in an organ or tissue due to the response to a stimulus
cause: growth factor-driven proliferation of mature cells and, in some cases, by increased production of new cells from tissue stem cells
Example case
acute bleeding or premature breakdown of red blood cells (hemolysis)
Apoptosis due to impairment in mitochondria
Growth factors stimulate the production of anti-apoptotic proteins protecting cells from apoptosis
BH3-only proteins “sense” damage and activate when cells are deprived of survival signals
BH3-only proteins may bind to and block the function of BCL2 and BCL-XL
when BAX-BAK is activated and the anti-apoptotic BCL2 family members lose their protective roles, several mitochondrial proteins that can activate the caspase cascade are released into the cytoplasm.
Apoptosome bind to the crucial mitochondrial pathway initiator caspase, caspase-9, and the enzyme cleaves adjacent caspase-9 molecules, thus setting up an auto amplification process.
active enzymes mediate the execution phase of apoptosis
Cell injury due to ischemic condition
Ischemia
compromises the delivery of substrates for glycolysis
Ischemia causes more rapid and severe cell and tissue injury than hypoxia.
Mechanism
Restoration of blood flow to ischemic tissues can promote recovery of cells if they are reversibly injured but can also paradoxically exacerbate cell injury and cause cell death
Reperfused tissues may sustain loss of viable cells in addition to those that are irreversibly damaged by ischemia.
Disorders in oral cavity
Osteoporosis
Introduction to Clinical Dentistry
Vivian(2106717783)