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