One more type of tissue to discuss

1. One more type of tissue to discuss • A type of tissue that none of us want in our body

2. Cancer

3. Cancer • Cancer accounts for nearly one-quarter of deaths in the United States, exceeded only by heart diseases. In 2003, there were 556,902 cancer deaths in the US.

4. % of all Deaths Cause of Death • Heart diseases • Cancer • Cerebrovascular • Chronic Respiratory • Accidents • Diabetes • Flu and pneunomia • 28% • 22% • 6.4% • 5.2% • 4.5% • 3.0% • 2.7%

5. Cancer • 1 in 4 deaths are due to cancer • 1 in 17 deaths are due to lung cancer • Lung cancer is the most common cancer in men • Breast cancer is the most common cancer in women

6. Cancer • There are over 100 different forms of cancer

7. Lung cancer cells

8. Breast cancer cells

9. Brain Cancer Cell 

10. Prostate cancer cell

11. Colon Cancer cells

12. Cancer cell under attack by the immune system

40. The division of normal cells is precisely controlled. New cells are only formed for growth or to replace dead ones. • Cancerous cells divide repeatedly out of control even though they are not needed, they crowd out other normal cells and function abnormally. They can also destroy the correct functioning of major organs.

41. Ancient Awareness • 80 Million years ago – Dinosaur bones show evidence of cancer • 3000 BC - Egyptian mummies – bone cancer • 1600 BC – Egypt – 8 cases of breast tumors (or ulcers) Treated by cauterization – with the “fire drill”

42. Ancient Awareness • 300 BC – Hippocrates named tumors as carcinos or carcinoma – tumors spread out like legs of a crab • 1500 – autopsy start to provide a greater understanding of cancer • 1650 – more knowledge with advance in medical science tools like the microscope

43. What is Cancer? • Cancer is the uncontrolled multiplication of cells. • Benign – cancerous cells are contained in one place • Malignant – cancerous have spread to other areas

44. What causes cancer? • Cancer arises from the mutation of a normal gene. • Mutated genes that cause cancer are called oncogenes. • It is thought that several mutations need to occur to give rise to cancer

45. What causes cancer? • Cells that are old or not functioning properly normally self destruct and are replaced by new cells. • However, cancerous cells do not self destruct and continue to divide rapidly producing millions of new cancerous cells.

46. A factor which brings about a mutation is called a mutagen. • A mutagen is mutagenic. • Any agent that causes cancer is called a carcinogen and is described as carcinogenic. • So some mutagens are carcinogenic.

47. Carcinogens • Ionising radiation – X Rays, UV light • Chemicals – tar from cigarettes • Virus infection – papilloma virus can be responsible for cervical cancer.

48. Carcinogens • Hereditary predisposition – Some families are more susceptible to getting certain cancers. Remember you can’t inherit cancer its just that you maybe more susceptible to getting it.

49. Benign or malignant? • Benign tumorsdo not spread from their site of origin, but can crowd out (squash) surrounding cells eg brain tumor, warts. • Malignant tumorscan spread from the original site and cause secondary tumors. This is called metastasis. They interfere with neighbouring cells and can block blood vessels, the gut, glands, lungs etc.

50. Genetically altered cell • The DNA of the cell highlighted above has a mutation that causes the cell to replicate even though this tissue doesn't need replacement cells at this time or at this place.