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17 Cards in this Set
- Front
- Back
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Atrophy
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decrease in size of tissue from decrease in cell size of individual cells
Causes: disuse, reduced fxnal demand, loss of stimuli, insufficient nutrients, decreased blood flow, persistent cell injury & aging adaptive & reversible |
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Hypertrophy
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increase in cell size & fxning tissue mass to acheive equilibrium b/t demand & fxnal capacity
results from increased workload on organ/body part (cardiac, skeletal) result of normal physiologic & pathologic conditions Pathologic- result of disease condition; adaptive (thickening of urinary bladder from long continued obstruction of urinary outflow) & compensatory (enlargement of remaining organ/tissue after portion removed/inactive) limiting factor for increased growth |
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Hyperplasia
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increase in number of cells in organ/tissue
occurs in tissue capable of mitotic division activation of genes controlling proliferation controlled process; response to stimulus; stops after stimulus removed physiologic- hormonal stimulation, increased fxnal demand, compensatory mechanism response of connective tissue in wound healing |
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Metaplasia
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one adult cell type replaced by another
involve reprogramming of stem cells occurs in response to chronic irritation & inflammation; substitution for better cell survival |
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Dysplasia
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deranged cell growth
vary in size, shape & appearance implicated as precursor to cancer sequential mutations in cell population adaptive process & doesnt necessarily lead to cancer |
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Mechanisms of Cell Injury
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Depletion of ATP: associated w/ hypoxia & chemical cell injury
effects-cellular swelling, loss of enzymes & proteins, leakage of lysosomes Free Radical Injury: highly reactive chemica; w/ unpaired electron in outer ring engages into rxns within cell, particularly key molecules damages cell membranes, cross-linking of cell proteins, inactivates enzymes, damages nucleic acids Impaired Calcium Homostasis: Ischemia & toxins lead to increase in Ca; activates enzymes in cell w/ damaging effects |
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Cell Death
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Apoptosis: eliminates cells worm out, excess, damaged & developed improperly
induced by program; targeted for phagocytosis; propagated by proteases Necrosis: cell death still part of living person unregulated enzymatic digestion; loss of membrane integrity; initiation of inflammatory response |
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Protein Synthesis
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proteins are enzymes that catalyze chemical rxns in cell
synthesis in cytoplasm; RNA assembles proteins Transcription: copy genetic code w/ instructions for synthesis from DNA to mRNA mRNA attaches to DNA, transcribes genetic code, diffuses into cytoplasm Translation: mRNA binds to rRNA, comunicates intruction to tRNA which delivers correct AA to its proper position on peptide chain |
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Chromosomes
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storage of genetic information
in pairs; maternal & paternal pair=homologous chromosomes 23 pairs; 22 autosomes & 1 sex chromosome |
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Cell Division
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cells duplicate chromosomes & divide in 2
Mitosis- nongerm cell replication Meiosis- Mitotic Divisions I & II I- homologous chromosomes pair & form synapse II- each of 23 pairs of chromosomes divide @ centromeres & create 2 more daughter cells results in 4 daughter cells |
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Single Gene Disorders
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caused by single defect on mutant gene
follow Mendelian pattern of inheritance may be expressed in different pts of body Autosomal Dominant: Marfan's Syndrome & Neurofibromatosis Autosomal Recessive: Phenylketonuria, Tay-Sachs Disease X-Linked: Fragile X Syndrome |
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Autosomal Dominant Disorders
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single gene disorder
single mutant allele transmitted from affected parent to child regardless of sex abnormality in structure of protiens may manifest as new mutation Marfan Syndrome: connective tissue defect; range of variation in gene expression cardio most life-threatening Neurofibromatosis: tumors arising from Schwann cells and other PNS cells genetic defect in tumor supressor protein regulating cell growth |
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Autosomal Recessive Single Gene Disorders
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single gene disorders
only when both members of gene pair affected deficiencies in enzymes Phenylketouria: metabolic disorder; caused by deficiency of liver enzyme converting AA phenalynine to tyrosene mental retardation, microcephaly, delayed speech, impaired neurologic development Tay-Sachs: lysosomal storage disease; failure of lysosome degradation weakness, flaccidity, deterioration of motor & mental fxn, seizures --> death |
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X-Linked Single Gene Disorders
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singe gene disorders
associated w/ X chromosome; affect males Fragile X Syndrome: decrease in gene length mentally retarded |
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Multifactoral Inheritance Disorders
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caused by multiple genes & environmental factors
tend to involve organ/tissue derived from same embryonic developmental field & risk of recurrence in future pregnancies is for the same or similar defect |
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Chromosomal Disorders
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acount for large # of spontaneous abortions, congenital malformations & mental retardation
develop during meiosis w/ failure of chromosome separation, rearrangement of genetic info or breakage leading to loss of genetic material EXs: Down Syndrome (Trisomy 21)- combination of birth defects risk increases w/ maternal age physical features: small head, upward slanting of eyes, small malformed ears, open mouth, large protruding tounge congenital heart defects, risk of GI malformations prenatal screening test Turner Syndrome (Monosomy X)- absence of all/pt of chromosome almost all spontaneously aborted girl short in stature, absence of ovaries, no secondary sex characteristics Kleinfelter's Syndrome- testicular dysgenesis w/ presense of extra X chromosoes enlarged breasts, sparse facial hair, small testes, inability to produce sperm, tall stature, abnormal body proportions, sexual dysfunction, infertility |
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Disorders d/t Environmental Influence
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FAS- physical, behavioral & cognitive abnormalities resulting from alcohol consumption
harmful effects throughout pregnancy prenatal/postnatal growth retardation, developmental delays, intellectual impairment, skull/brain malformation vary in severity diagnosis: three facial abnormalities, growth defects & CNS abnormalities Folic Acid Deficiency- neural tube defects |
