Cell Cycle and Mitosis Uncontrolled Cell Growth. Benign Does not spread Does not spread Easily...
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Transcript of Cell Cycle and Mitosis Uncontrolled Cell Growth. Benign Does not spread Does not spread Easily...
Cell Cycle and MitosisCell Cycle and Mitosis
Uncontrolled Cell GrowthUncontrolled Cell Growth
Uncontrolled Cell GrowthUncontrolled Cell Growth
Benign Benign Does not spreadDoes not spread Easily removedEasily removed
Malignant cancerMalignant cancer Spreads to other cells and tissuesSpreads to other cells and tissues Difficult to remove because it invades so may Difficult to remove because it invades so may
other cellsother cells
Benign GrowthBenign Growth
Easily removedEasily removed WartsWarts PolypsPolyps Benign tumorsBenign tumors
CancerCancer
Defined as uncontrolled cell division Defined as uncontrolled cell division coupled with the capacity to spread coupled with the capacity to spread ((metastasismetastasis) to other locations in the body ) to other locations in the body
Cancer cells actually build new blood Cancer cells actually build new blood vessels to send blood to the center of a vessels to send blood to the center of a tumortumor
Testicular CancerTesticular Cancer
The red and white areas are cancer cells.The red and white areas are cancer cells.
Breast cancerBreast cancer
Low magnificationLow magnification
Skin CancerSkin Cancer
Lung CancerLung Cancer
Healthy vs. CancerousHealthy vs. Cancerous
Cancer cells are characterized by:Cancer cells are characterized by:
No contact inhibitionNo contact inhibition cells continue to grow and divide even after cells continue to grow and divide even after
contacting other cellscontacting other cells No "anchorage" dependency No "anchorage" dependency
Does not need to be attached to anythingDoes not need to be attached to anything No requirement for external growth factorsNo requirement for external growth factors
Most cells rely on hormones to tell them when and Most cells rely on hormones to tell them when and how to grow.how to grow.
Failure to differentiateFailure to differentiate cells stay immature instead of changing into skin cells stay immature instead of changing into skin
cells, heart cells, lung cells, etc.cells, heart cells, lung cells, etc.
Why does a cell become Why does a cell become cancerous?cancerous?
OncogeneOncogene A mutation in DNA causes the cell to continue A mutation in DNA causes the cell to continue
dividing.dividing. Tumor-Supressor geneTumor-Supressor gene
This gene normally tells the cell to stop This gene normally tells the cell to stop dividing.dividing.
In cancer cells this gene has been changed, In cancer cells this gene has been changed, or mutated.or mutated.
TreatmentsTreatments
SurgerySurgery removes tumors, but ineffective if the cancer has removes tumors, but ineffective if the cancer has
spread spread
RadiationRadiation prevents mitosis, so cancer cells are especially prevents mitosis, so cancer cells are especially
vulnerable. vulnerable. Sometimes coupled with temporary bone marrow Sometimes coupled with temporary bone marrow
transplants. transplants. Ineffective if the cancer has spread, because the Ineffective if the cancer has spread, because the
entire body cannot be irradiated. entire body cannot be irradiated.
Treatments cont.Treatments cont. ChemotherapyChemotherapy
relies on a wide variety of drugs to find cancer cells relies on a wide variety of drugs to find cancer cells and destroy them, or to prevent the formation of and destroy them, or to prevent the formation of supporting tissue (e.g. new blood vessels). supporting tissue (e.g. new blood vessels).
Unfortunately, these drugs also kill healthy cells (hair Unfortunately, these drugs also kill healthy cells (hair follicles and intestinal lining), producing the well-follicles and intestinal lining), producing the well-known side effects of hair loss and nausea. known side effects of hair loss and nausea.
ImmunizationImmunization once thought impossible due to diverse nature of once thought impossible due to diverse nature of
cancer, but now there is some hope through of the cancer, but now there is some hope through of the action of new antibodies.action of new antibodies.
Fighting Cancer: BeforeFighting Cancer: Before
A fully intact cancer A fully intact cancer cell surrounded by cell surrounded by the immune system’s the immune system’s killer t-cells.killer t-cells.
Notice the tentacles Notice the tentacles of the cancer cell. of the cancer cell.
Fighting Cancer: AfterFighting Cancer: After
Notice how the cancer is Notice how the cancer is completely flattened and completely flattened and totally destroyed. totally destroyed.
A t-cell pokes holes in the A t-cell pokes holes in the cell membrane of the cell membrane of the cancer cell, allowing fluid cancer cell, allowing fluid and salts enter so that and salts enter so that the target cell eventually the target cell eventually bursts. bursts.