What is the aging

What is the aging?

 

Introduction

Whenever we are older according to the years, our age increases 1 year. But in the biological point of view, our body age is not same as just 1 increase of year compared with the number and the 1 year increase has different effect to our body every year. So I need to define new concept of ages about our body. I want to suggest biological ages by comparing physiological function in body.

 

Result

Skin

Most of changes related age occur after 40 years beginning to have a problem for dermis. The number of collagen fibers in dermis decrease and the dermis starts to be stiff. Elastic fiber decrease elasticity. Fibroblast which produce collagen and elastic fiber also decrease. As the result of the aging, the skin form crevice and furrow called wrinkles.

 

Bone

From birth to adolescence, more bones are produced and more bones are lost by the remodeling of bone formation. In young adult, the rate to produce bones is same as loss, and in middle ages(after 50 years), especially after menipause in woman, the decrease of bone occur. Generally, because the bone size of woman is smaller than man, the loss of bone is more critical problem in woman. So because of these factors, female has higher possibility about osteoporosis

 

Muscle

After 30 years, human progressively reduces skeletal muscle by replacing as adipose tissues and connective tissues. This loss leads to decrease of physical activity, maximal strength of muscle and flexibility. But through exercises, it can make slow the loss of muscle and even reverse the effect of age.

 

Brain

Brain grow rapidly in short period. This growth is due to increase of neuron size and proliferation of neuroglia. But the size of brain decrease from early adulthood. In age of 80 years, the brain size decrease more 7 percent than young adulthood. This decrease leads to low ability to send nerve impulse to brain, so reduce the processing of information

 

Heart

In general changes, elasticity of aorta decreases, the amount of cardiac muscle decreases, also maximum heart rate decreases and blood pressure increases. By age 80, the amount of blood flow to brain is less 20 percent and blood flow to kidney is less 50 percent.

 

Telomere

Telomere is end part of the chromosome. This part shortens in cell division and if the length of telomere is less than some degee, the cell dies through apoptosis. Because stem cell has telomerase, cell can divide persistently. But the telomerase also decrease activity according to the aging and the cell die through apoptosis.

 

Conclusion

When I think these physiological effect and telomere, I can define the biological age as degree of function of gain and loss. From birth to adolescence, gain of function occur such as growth of brain, muscle and bone and from adolescence to adult, maintenance of the function and from adult to death, loss of function occur such as decrease of brain size and muscle mass. And I can analyze there is a critical period for physiological function according to the time. So at the result, I can define the biological age has 3 steps : gain, maintenance, loss of function.

Further question

The loss of function is due to decrease of activity of telomerase and the cause of the decrease is environmental effect. But if environmental effect is ideal, do people live forever? or Is the biological age fixed? Can we reverse the biological age by change the environmental factors?