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Explore the intricate processes of cell regulation, mitosis, and cancer cell growth, including checkpoints in the cell cycle, the impact of density-dependent inhibition, and treatments like chemotherapy and radiation. Learn about the different types of tumors, apoptosis, and the potential of stem cells in medical advancements.
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Cell Growth • Anchorage Dependence • Density Dependent Inhibition • Volume to Surface Area Ratio
Interphase 3 parts G1, S phase, G2
Cell Cycle Control System 1. G1 Checkpoint – initiates beginning of S phase (Nerves and muscle cells are stuck at G1 2. G2 Checkpoint - initiates M phase 3. M checkpoint – chromatids attached to spindle stimulates separation of sister chromatids in anaphase.
Cancer – disease of the cell cycle • Affecting Factors – • 1. No Density Dependent Inhibition • A. some may grow without growth factors and bypass checkpoint • B. Some secrete growth factors • C. Some exhibit reduced need for anchorage
Tumors – abnormal mass of cells due to excessive growth 1. Benign – abnormal mass of “normal” cells A. Secondary problems B. Do not migrate 2. Malignant – mass of cells capable of spreading to other tissues and body parts A. Replaces normal tissues B. Metastasis – spread thru blood stream or lymphatic system
Cancers Named by Originating Location 1. Carcinomas – arise in external or internal coverings of body (skin, intestinal lining) 2. Sarcomas – arise in tissues that support body (muscle, bone) 3. Leukemias and Lymphomas – arise in blood-forming tissue (bone marrow, spleen, lymph nodes)
Treatment of Cancers • 1. Radiation – disrupts cell division • A. Disadvantage – may destroy healthy • cells along with cancerous cells 2. Chemotherapy – disrupts cell division A. Vinblastin - prevents spindle fibers from forming B. Taxol – freezes spindle fibers
Apoptosis – programmed cell death 1. Removes damaged and unwanted cells 2. May protect against cancer growths
Stem Cells – unspecialized cells that differentiate into specific cells • 1. Embryonic Stem Cells – fertilized egg is a zygote. Cells continue to divide producing the • A. Endoderm • B. Mesoderm • C. Ectoderm EX: grow pancreatic cells to cure diabetes 2. Adult Stem Cells – can be stimulated to produce more of “its” type of tissue. Ex: growth of sheets of skin