THE CANCER/MITOSIS THE CANCER/MITOSIS CONNECTIONCONNECTION

A cance

r cell

All cells have a All cells have a controlled rate of controlled rate of division that is division that is appropriate for their appropriate for their role in the body.role in the body.

Rates of DivisionRates of Division

ex. The cells of ex. The cells of the the skinskin reproduces reproduces perfectly so that perfectly so that it does not it does not become too thin become too thin or too thickor too thick

Rates of DivisionRates of Division

Ex. Cells that line Ex. Cells that line the the intestineintestine complete the cell complete the cell cycle in 24-28 cycle in 24-28 hourshours

Rates of DivisionRates of Division

Ex. Ex. LiverLiver cells cells reproduce only reproduce only once a yearonce a year

Rates of DivisionRates of Division

Ex. Ex. NerveNerve cells never reproduce cells never reproduce

Rates of DivisionRates of Division

Ex. Ex. Frog Frog embryo embryo cellscells reproduce in reproduce in less than an less than an hourhour

Rates of DivisionRates of Division

Cells spend most of their time in Cells spend most of their time in interphase. interphase.

The mechanism for cell growth is The mechanism for cell growth is highly regulated by genes (segments highly regulated by genes (segments of DNA) in the cell so that you just get of DNA) in the cell so that you just get the new cells you need.the new cells you need.

Rates of DivisionRates of Division

If the control If the control mechanism for mechanism for this process this process gets messed gets messed up, the rate of up, the rate of mitosis in that mitosis in that body tissue body tissue increasesincreases

Increased Mitosis …Increased Mitosis …

Leads toLeads to– Accumulation of cells in that Accumulation of cells in that

area known as a area known as a TUMORTUMOR

Kidney tumors

Increased Mitosis …Increased Mitosis …

Leads toLeads to– CANCERCANCER

A disorder of cells in which the genes A disorder of cells in which the genes which control growth have been which control growth have been damageddamaged and the cells have the ability and the cells have the ability to to spreadspread throughout the body. throughout the body.

Ovary Cancer Cell

Causes of cancerCauses of cancer::

VirusesViruses

Chemicals (such Chemicals (such as Nicotine, as Nicotine, Benzene, Benzene, Asbestos)Asbestos)

Ultraviolet Ultraviolet radiationradiation

The ozone absorbs some, but not all of the types of UV radiation: UVA: Not absorbed by the ozone layer.

UVB: Mostly absorbed by the ozone, but some does reach the Earth’s surface. UVC: Completely absorbed by the ozone layer and oxygen.

UVA and UVB that reach the Earth’s surface contribute to serious health effects.

Causes of Cancer:Causes of Cancer:

These are called These are called CARCINOGENSCARCINOGENS: : cancer-causing agents (also called cancer-causing agents (also called MUTAGENS)MUTAGENS)– Exposure to these Carcinogens is Exposure to these Carcinogens is

cumulative, meaning the longer you’re cumulative, meaning the longer you’re exposed the greater your risk.exposed the greater your risk.

– Carcinogens attack DNA and Carcinogens attack DNA and mutatemutate the genes that controls cell divisionthe genes that controls cell division

These “control” genes are called These “control” genes are called ONCOGENESONCOGENES

KindsKinds of tumors: of tumors:

BENIGNBENIGN: Harmless because do not : Harmless because do not spread to other tissues of the bodyspread to other tissues of the body– Ex. Warts (caused by a virus)Ex. Warts (caused by a virus)

Kinds of tumors:Kinds of tumors:

MALIGNANTMALIGNANT: :

= = CANCERCANCER– Very dangerousVery dangerous– Spreads to Spreads to

different kinds of different kinds of tissues (called tissues (called METASTISIS)METASTISIS)

– interferes with interferes with organ functionorgan function

CancerCancer

Cancer cells do not carry on normal Cancer cells do not carry on normal functions, all their energy goes into functions, all their energy goes into dividing. dividing.

They also use up the nutrients for cells They also use up the nutrients for cells so they can’t do their job as well.so they can’t do their job as well.

Cancer TreatmentsCancer Treatments

Surgery:Surgery: removal of cancerous removal of cancerous cells, hopefully before it can cells, hopefully before it can spread.spread.

Radiation Therapy:Radiation Therapy: burn burn and/or kill all cells in the areaand/or kill all cells in the area

Chemotherapy:Chemotherapy: medication that medication that destroy all rapidly destroy all rapidly dividing cells dividing cells (including cells that (including cells that grow hair, line the grow hair, line the gut, produce gut, produce sperm, produce sperm, produce nails, produce blood nails, produce blood cells)cells)

Cancer TreatmentsCancer Treatments

So…So…

There are many different forms of cancer, There are many different forms of cancer, all with varying threat levels to a person’s all with varying threat levels to a person’s health. A person’s susceptibility and health. A person’s susceptibility and ability to fight cancer depend on their ability to fight cancer depend on their health, physical activities, heredity, the health, physical activities, heredity, the environment they live in and access to environment they live in and access to health care. health care.

In short, Cancer, in all its various forms, is In short, Cancer, in all its various forms, is uncontrolled cell division that leads to a uncontrolled cell division that leads to a tumor with the ability to spread to tumor with the ability to spread to different tissues in the body. different tissues in the body.