The secret of the biological clock that controls life span is actually hidden in the cells

There are more than 8.7 million species on Earth. They have different forms, but they all cannot escape the fate of birth, aging, illness and death. The life span of organisms has always been one of the mysteries that scientists are most concerned about: Why do organisms age and die? What exactly affects the limit of life span? This may start with the most basic unit of life - cells.

Cellular limitations determine the inevitability of aging

Cell aging does not happen overnight. When old cells gradually age and the supply of new cells cannot keep up with the speed of cell renewal, it will cause the aging of tissues and organs, and over time, life will enter the twilight period.

Aging is reflected in all parts of the body. The first signs of aging often appear in the muscle and skeletal system: muscle tissue quality and muscle strength decrease, bone density decreases, bones become porous, joints are more susceptible to injury, and recovery from injury slows down.

The aging of the cardiovascular system is manifested in the increasing stiffness of the heart and blood vessels. The stiff arteries cannot expand effectively, leading to high blood pressure. Therefore, hypertension is very common among middle-aged and elderly people.

Due to changes in hormone levels, the reproductive system also faces aging problems: the decline in male sex hormone testosterone levels leads to a decrease in sperm count and decreased libido, the female sex hormone level drops significantly, menstruation gradually stops, the reproductive system atrophies, and there are symptoms such as frequent and urgent urination.

The aging of the nervous system will bring about health problems such as memory loss, slow movements, poor sleep, and decreased brain function.