The human body is a complex and wondrous living machine like any machine our bodies are composed of smaller parts that work together. The various tasks that are performed each day such as breathing eating and digesting food and the movement of our blood are performed by specialized structures known as organs.
Examples of organs include the lawn’s stomach heart.
All of these organs and other body parts like our skin and muscles are made of smaller living units called cells. Our lines are a good example of how many cells work together to perform a specialized task. The cells in our lawns work together to allow us to take in oxygen from the air and get rid of waste products such as carbon dioxide. Our lungs are composed of many millions of sales working together to accomplish this task. Cancer is the result of a long process that begins when one of the cells in an organ or tissue becomes damaged.
Altered in a way that causes it to break free from the normal controls that allow ourselves to work together in harmony. A group of misbehaving cells can cause the same kinds of problems and a body that a defective part would call in any other type of machine. A normal cell will divide only when it receives a chemical signal telling it to do so these signals are interpreted in the nucleus and the cells reproduce their genetic information and divide into two identical daughter cells through a process called mitosis. Cancer cells do not obey this rule and we’ll divide it even if they do not receive appropriate signals.
In addition to the signals that normal cells received telling them to divide, they’re also told when to stop dividing this prevents too many cells from being may. In fact, the cell division process is a highly ordered process this is a critical issue in cancer because cancer cells do not obey all require normal signals for the division.
This can lead to the formation of a mass of cells that piles up and may form a tumor.
Also different from normal cells is the ability of cancer cells to continue dividing indefinitely.
An important point about cells is that no matter what their job is in the body they all have the same general structure.
The cells that make up our lawn’s heart or brain are all similar in their overall appearance even though their jobs are quite different. Just as the organs that the former maid of smaller structures cells themselves are composed of smaller parts that help them perform their jobs these smaller structures are called organ els of particular importance in cancer is the organ L. known as the nucleus. The nucleus can be thought of as the brains of a cell it contains the information that acts as the blueprint for each and every one of us just as a manual would contain instructions to assemble a chair.
Specifically, this information is contained within the chromosomes that reside in the nucleus.
Individual units of information.
Are called genes.
At a chemical level jeans are made of deoxyribonucleic acid.
All of our cells contain the same set of information it is only how the information is you that makes them different for example cells in the loans use different bits of the blueprint to do their job then the cells in our stomach in cancer changes to the DNA because some of the genes to fail to perform what to do their job in a way that causes problems with the affected individual.
In short, all cancers are thought to result from changes to DNA the altar critical genes and change the behavior of the affected cells.
If a change occurs to the nucleotide sequence it is like having the letters of a word changed an alteration in a team this call the mutation how do all these changes occur there are actually a number of different things that can cause mutations examples to include chemicals that can be swallowed or inhaled such as those found in chewing tobacco and cigarette smoke and radiation from the sun or artificial sources like a tanning bed.
Sometimes mutations occur without any known external because they just happen.
Certain genes make products that lead sales to reproduce this would be equivalent to the gasoline system in the car.
The genes that are responsible for making cells divide are known as proto-oncogenes changes in these normal jeans lead to the production of oncogenes the result may be cells that divide in the absence of proper signals.
It is the equivalent.
Of a gas pedal that is stuck in the on position making a cargo even when no foot is pushing down.
Jeans whose products function as the equivalent.
Of cellular breaks.
As a group.
These jeans are known as tumor suppressors.
Humans have two copies of each gene one inherited from each parent if a single copy of a tumor suppressor is damaged another copy is usually able to stop the cell from behaving abnormally.
This would be like losing either the front or rear brakes of a car.
The car may be damaged but would still be able to stop.
But if the second set of brakes is damaged as well the car would not be able to stop just as the cell will not be able to stop dividing if both copies of the tumor suppressor genes.
The process by which to me is because the body to provide them with nutrients is known as angiogenesis like the hungry plant in the little shop of horrors a growing tumor sends out signals that essentially say feed me.
The messages from the tumors because nearby blood vessels to send over new extensions that deliver food and oxygen.
The blood vessels also service the passageway for the movement of tumor cells to neighboring and distant parts of the body.
Spread of tumors to distant locations is of great importance in cancer about ninety percent of the deaths due to cancer involve tumors that have spread around the body the movement of tumor cells to other parts of the body is known as metastasis.
Metastasis is a complex process during which cancer cells to break off of the original or primary tumor and moved to the body to form tumors at new locations.
From the point of view of a cancer cell, this is a dangerous and often unsuccessful process the trip through the body is full of hazards that cause the death of most cells that begin the journey even tough cancer cells.
To begin the process individual cells must break away from the tumor and invade nearby vessels.
The cells crawl along the surface of other sales and the fibrous stringy structures surrounding them and then forced their way in shown here is the invasion of the blood supply once inside a blood vessel the cancer cells may