Pathopharm Quiz 1 completed A

Pathopharm Quiz 1 Pathopharm Quiz 1 Ribosome Function synthesize protein, helps mRNA and tRNA make polypeptides. Free Radicals Molecules responsible for aging and tissue damage Adenosine triphosphate (ATP) Energy carrying or transferring molecule. Synthesizes organic molecules. Used by cell for muscle contraction and active transport of molecules across cell membranes. (STORE AND TRANSFER ENERGY) Somatic Cells contain 46 chromosomes (23 pairs) 1 from mother and 1 from father. How are new somatic cells created? Mitosis and cytokinesis. the nucleus and cytoplasm are replicated Diploid cells ex. somatic cells bc they occur in pairs Aneuploidy a somatic cell that does not contain a multiple of 23 chromosomes Meiosis Haploid cells are formed from diploid cells Haploid cells i.e gametes, Sperm and cell eggs, contain 23 chromosomes each What causes aneuploidy? Nondisjunction, failure of homologous chromosomes to separate properly during meiosis or mitosis. Trisomic aneuploidy cells containing 3 copies of 1 chromosome What affected chromosomes can children survive with? 13,18,21 Partial trisomy only an extra portion of the chromosome is present in each cell. Monosomy the presence of only 1 copy of a chromosome in a diploid cell. This is lethal. Karyotype the number, size and shape of a chromosome Autosomes 1st 22 pairs of chromosomes Autosomal aneuploidy abnormal karyotype, i.e Down Syndrome (1 in 800 live births) What is an example of aneuploidy in sex chromosomes? Trisomy X, 3 X chromosomes (1 in 1,000 births), Klinefelter, Turners S/S Trisomy X sterility, menstrual irregularity, and cognitive defects (worsens w/ added X chromosomes) Klinefelter Syndrome aneuploidy sex chromosome, individuals have at least 1 Y and 2 X chromosomes. What is the karyotype for Klinefelter? 47, XXY S/S Klinefelter male appearance, usually sterile, 1/2 develop gynecomastia, small testes, sparse body hair, high pitched voice, elevated stature and a moderate degree of mental impairment. (1 in 1,000 male births) What affects the amount of X's in Klinefelter's Syndrome? increases w/ the mother's age Turner Syndrome aneuploidy sex chromosome, females have 1 X chromosome, usually inherited from mother, thus most cases are caused by the loss of the paternal X chromosome (1 in 2,500 female births) What karyotype does Turner's syndrome have? 45, X S/S Turner's Syndrome absence of ovaries, short stature, webbing of neck, widely spaced nipples, coarctation of the aorta, high number of aborted fetuses, and X chromosome. Treatment for Turner Syndrome Estrogen in teenagers to promote secondary sexual characteristics. Differentiated cells benign tumors Undifferentiated cells malignant tumors Malignancy rapid growth, not encapsulated, invasive, poorly differentiated (anaplasia), high mitotic index, can metastasize. Are named according to the tissue they arise from. Functions of Cancer cells Transformation, metabolism, self-renew Transformation of cancer cells a normal cell becomes a cancer cell, have autonomy, is immortal and lacks contact inhibition, anchorage independent, anaplasia occurs Metabolism of cancer cells perform glycolysis, allows lactate and its metabolites to be used to the more efficient production of lipids and other molecular building blocks needed for rapid cell growth. Self renew of cancer cells cell divisions create new stem cells How do cancer cells develop the ability to metastasize? gene mutations, deletions, translocations, epigenetic silencing, and changes in mRNA expression. Metastasis the spread of cancer cells from the site of the original tumor to distant tissues and organs, requires cells to INVADE (locally spread, 1st step), then regional lymphs to lymphatic system and distant organs through bloodstream. What is protease? something cancer cells secrete and it digests the extracellular matrix and basement membranes allowing the cells to travel Angiogenesis recruitment of new blood vessel growth. What mechanisms are important for local invasion? recruitment of macrophages and other cell types to the primary tumor; where they promote digestion of connective tissue capsules and other structural barriers by secreted protease. What are capsules surrounding tumors made of? epithelial cells and myoepithelial cells (may be tumor suppressive and angiogenesis inhibitors), contained by a basement membrane. Warburg Effect tumors consume large quantities of glucose to make cellular building blocks BMR w/ Malignancy Warburg effect, oxidative stress as a weapon to extract recycled nutrients from cancer associated fibroblasts in stromal tissue (reverse Warburg effect). Oncogenes mutant genes that in their non-mutant state direct protein synthesis and cellular growth Tumor suppressor genes encode proteins that, in their normal state, negatively regulate (stop) proliferation. (AKA anti-oncogenes). Proto-oncogenes normal non-mutant genes that code for cellular growth. Activation of Proto-oncogenes resulting in hyperactivity of growth related gene products (called oncogenes) Mutation of genes Resulting in the loss of the tumor suppressor genes, over-expression of products that prevent normal cell death or apoptosis Colon Cancer 2nd occurring annually in US. Risk is increased by 2-3x if 1st degree relative is affected. Clusters in families. Environmental causes of colon cancer High fat, low fiber diet, chronic inflammation r/t bacteria, viruses, autoimmune process, toxins What gene mutation plays a vital role in familial adenomatous polyposis? APC, inherited adenomatous coli Procarcinogens a chemical substance that becomes a carcinogen only after it is altered by the metabolic process. Risk factors for cancer Tobacco use (1/3 of all cancers), mutated proto-oncogenes, loss of tumor suppressor genes, single gene defects, chromosome aberrations, deletions, fragility, translocations, amplifications, drugs, pesticides, ionizing radiation, anabolic steroids, cytotoxic chemo Which cancers are linked to Trisomy 21 (Down Syndrome) Leukemia, familial risk, Wilm's tumor, and retinoblastoma What cancer is linked to pesticide exposure? Leukemia Deletions a type of abnormal structure of chromosomes (aberrations), broken chromosomes and loss of DNA. Most common deletion example Cri Du Chat Syndrome, deletion of part of the short arm of chromosome 5 S/S Cru Du Chat Syndrome low birth weight, mental retardation, small head Duplications type of abnormal structure of chromosomes, excess genetic material and usually has less serious consequences. Inversion abnormal structure of chromosomes, 2 breaks on a chromosome followed by the reinsertion of the missing fragment at its original site but in inverted order. No loss or gain of genetic material. A balanced alteration w/ no apparent physical effect. Concern w/ children of affected Inversion parents offspring may have deletions or duplications Cystic fibrosis autosomal recessive disease, appears in children, not the parent, gene forms sodium channels with defective transport, leads to salt imbalance w/ abnormally thick dehydrated mucus. Does NOT survive past 40 years of age What organs are affected w/ Cystic Fibrosis? Lungs and pancreas Concordant trait both members of a twin pair share a trait Epigenetics a type of gene change w/ cancer, changes are potentially reversible and may precede genetic mutations. Causes of genetic modifications Oxidative stress, DNA/protein damage, environmental factors, diet, aging Gene silencing inheritance of silencing occurs during cell division and does not require mutations or change in DNA sequence. Caused by chemical modification. DNA Methylation the attachment of a methyl group to a cytosine base that is followed by a guanine base; also known as CpG dinucleotide, causes a gene to be transcriptionally inactive or silent Autosomal Dominant 50% chance of passing on, NOT SEX LINKED, no generation skipping. Autosomal Recessive 25% chance of passing on, 50% carriers, 25% normal X-linked inheritance Sex linked, skips generation, i.e Duchanne Muscular Dystrophy Example of Incidence rate Flu Example of Prevalence rate Obesity What cancers can be caused by Epistein-Barr Virus? cancers of the nasopharynx, Hodgkin disease, and non-hodgkin lymphoma What cancers can be caused by Herpes virus type 8? Karposi Sarcoma What cancers can be caused by Human T-cell lymphotropic virus type 1? Leukemia and lymphoma What cancer can be caused by H. pylori? Stomach cancer What cancer can be caused by Hep B and C? Liver cancer What cancer can be caused by HPV? Cervical cancer What cancer can be caused by exposure to UV light? Basal cell carcinoma What are the number 1 childhood cancers? ALL (leukemia) and brain cancer Barr Body inactivated X chromosomes are observable in many interphase cells as highly condensed chromatic bodies, regulates the amount of X-linked genes, i.e women have 1 barr body, men have none. Atypical Hyperplasia Dysplasia refers to abnormal chances in the size, shape, and organization of mature cells, not considered a true adaptive process but is related to hyperplasia = atypical hyperplasia i.e Frequently encountered in epithelial cells of cervix and respiratory tract -Often found adjacent to cancerous cells; does not indicate cancer, may not progress to cancer -Atypical hyperplasia is a strong predictor of breast cancer development If inciting stimulus is removed, dysplastic changes are often reversible