Cancer
Jan 04, 2016
Cancer
Normal Cell Replacement
As you grow, mitosis adds to the total number of cells in your body
Mitosis continues after you are fully grown in order to maintain and repair your body
Cell Death
The lifespan of a cell is programmed into their genetic material
Cells die if they are damaged, no longer needed, cannot function normally, or receive ‘instructions’ to do so
Apoptosis is programmed cell death and causes cells to commit suicide
Life Spans of Different Human Body Cells
Brain cells = 30-50 years Liver cells = 200 days Red blood cells = 120 days Skin cells = 20 days Stomach lining cells = 2 days
Regeneration
The repair of damaged cells or lost body parts
Mitosis allows for cut skin or broken bones to heal
Humans cannot regenerate lost body parts (or can they?)
Limb regeneration in newts
Cancer
Disease in which a group of cells display uncontrolled growth
The cell cycle becomes out of control
Cells begin to pile up and form a tumour
Benign = non-cancerous Malignant = cancerous
A typical benign tumour
Massive benign tumour
Skin cancer (malignant)
Lung cancer (malignant)
Mouth cancer (malignant)
Metastasis
The spread of cancerous tumours throughout the body
Cancer cells destruct near-by cells
What can cause cancer?
Tobacco Asbestos Certain viruses (ex. HPV) Radiation (ex. UV rays) Heredity (ex. Colon cancer)
Smoking vs. Cancer