Aim: How can mitosis lead to a disruption in homeostasis?

What could have caused this? Cancer

Approximately 200 types Can you think of some? Breast cancer Lung cancer Skin cancer Can you think of some?

Healthy cells Grow, divide, and replace themselves during the process of mitosis. Each time mitosis happens it leads to the development of 2 NEW healthy cells.

How do cells divide by mitosis?

Abnormal cell division Sometimes, normal cells lose their ability to limit and direct their growth. They divide and grow too rapidly and out of control .

What happens if cells are unable to regulate the cell cycle? Cancer is a disease that is caused by loss of control of the cell cycle. Cancer is uncontrollable cell division!

Cancer Cancer: uncontrolled cell division Tumors (lumps or masses of cancerous cells) will form as a result of this uncontrolled cell division. Tumors can be either: malignant (spread = dangerous) benign (can’t spread = safe)

What causes cancer? Damage to the cells DNA from: Poor Diet Certain Pathogens (Viruses) Genetics UV Radiation (Sun) Drugs (Tobacco) Mutations - to genes, the cell's instructions for making the proteins it needs to survive, grow and multiply. Ultraviolet radiation Viruses Usually cancer is not inherited Carcinogens: chemicals A third of all cancers in the UK are linked to diet. Some types of food increase your risk, while others seem to have a protective effect. For example, a diet low in saturated fat, alcohol and red meat and high in fiber, fruit and vegetables can reduce your risk of some cancers, such as breast and colon cancer. Fruit and vegetables contain natural chemicals, antioxidants, that mop up free radicals: chemicals that can damage genes. Usually cancer is not inherited, even in families with several people affected, since it is a common disease. However, some people are born with an increased risk of cancer, because they inherit an altered gene important for cell growth or for repair of damaged DNA, for example. Scientists have already identified some of the genes that predispose to breast and colon cancer. There are likely to be others.

Metastasize Cancer cells also can spread, to other parts of the body and form new tumors. How do they spread? They spread by using the circulatory system and lymph nodes.

Anatomy of a Cigarette Smoking causes a third of all cases of cancer Cigarette smoke contains 3000 different chemicals, some of which are carcinogens. Some people have a lower risk of developing lung cancer. Their cells may be more efficient at repairing the gene damage caused by the carcinogens.

Lung Cancer: Healthy Lung Cancerous Lung

SKIN CANCERS

Melanoma Melanomas have the following characteristics (ABCD rule) A: Asymmetry; the two sides of the pigmented area do not match B: Border is irregular and exhibits indentations C: Color (pigmented area) is black, brown, tan, and sometimes red or blue D: Diameter is larger than 6 mm (size of a pencil eraser)

Treatment Surgery: physical removal of the malignant tumor Radiation: disrupts cell division Chemotherapy: drugs that prevent cell division by interfering with mitosis Certain body tissues, such as breast and prostate, require hormones to develop. When cancer originates in these tissues, it responds to hormones. This means that the cancer responds to hormonal manipulation, which includes the administration of hormones, the withdrawal of hormones, or interference with hormone function. For example, by using chemicals that block the action of these hormones, it is possible to slow down, or even stop, the growth of cancer cells