NUR 232 ATI MED SURG FINAL EXAM 1 Study Guide 2020/2021

MEDSURG I FINAL EXAM CANCER (21) Biology of cancer : difference b/w proliferation and differentiation o Normal cells  Proliferation • Stem cells-mature cells -stem cells have their own process -time is different • Cellular division • Contact inhibition  Differentiation • Protooncogenes • Tumor Suppressor genes • The divided cells are identical to parent cells. • The functional in the same way as parent cells. o Cancer cells  Defects in Proliferation • Proliferation is indiscriminate and continuous. • Producing more cells than normal. • No contact inhibition (can invade other organs and spaces)  Defects in Differentiation • Mutation • Proteins that change the cellular structure. • Lack of proper transfer of genetic information. Genes that can be affected by mutation o Protooncogenes  When this lock is “unlocked,” as may occur through exposure to carcinogens or oncogenic viruses, genetic alterations and mutations occur. • For example, some cancer cells produce new proteins, such as those characteristic of the embryonic and fetal periods of life. These proteins, located on the cell membrane, include carcinoembryonic antigen (CEA) and α-fetoprotein (FP). o Tumor suppressor genes  Mutations render them inactive.  Result in loss of suppression of tumor growth • Examples of tumor suppressor genes are BRCA-1 and BRCA-2. • Another tumor suppressor gene is the APC gene. Alterations in this gene increase a person’s risk for familial adenomatous polyposis, which is a precursor for colorectal cancer. Development of cancer o 1.Initiation  Mutation of cell’s genetic structure (exposure to chemicals radiation or viral) • From inherited mutation or exposure to chemical, radiation, viral agent