Biological Ageing (senescence) is a result of the gradual failure of the body’s cells and organs to replace and repair themselves.
This is because there is a limit to the number of times that each cell can divide. As the body’s cells begin to near this limit, the rate at which they divide slows down. Sometimes the new cells that are produced have defects or do not carry out their usual task effectively.
Organs can then begin to fail, tissues change in structure and the chemical reactions that power the body becomes less efficient. Sometimes, the blood supply to the brain is not sufficient. The brain cells become starved of oxygen and nutrients leading to forgetfulness.
Some Animals which you know do not age ! See also – Negligible Senescence
