Although you don't want to face the facts, you are no longer young more and more.Aging may let you feel excited, fear, or sad, or any experience in this several feel emotions.Needless to say, the transformation of different life stages are complex in emotional or physical process.

As we age, you experienced childhood, adolescence, adulthood and eventually into the middle and later stages.These life stages have brought all kinds of experience and joy.But what makes them different?What is adolescence?What is maturity?these阶段的转变期会何时发生？成人期什么时候会转变为中年期？

Please continue reading to explore the answers to these questions and more knowledge.Read the end of the article, you will be in adolescence, adulthood and middle age have a deeper understanding.You will also be able to explain the characteristics and definition of life stages.

What is adolescence: not just a teenager

Most people think that adolescents and teens is almost the same ethnic group.Although there are many of the same characteristics, but there are also differences.Teenagers aged from 13 began, end at the age of 19.Adolescence, on the other hand, from the age of ten and continue to in his early 20 s.

The age range is so wide because adolescence is refers to the transition from childhood to adult in physiological and psychological transition.This period, the body will experience great physical, emotional and social development.Because adolescence contains across more than 10 years of life, it is usually divided into three stages: the early, middle and late adolescence.Each period has a unique change and development:

Early puberty (10 to 13 years of age) :This stage of adolescence is why people hate school.Radical growth period usually start during this period (especially girls), other physical changes during this vigorous development, such as hair growth and the development of primary and secondary sexual characteristics.These dramatic changes quickly create preadolescent child embarrassed or discomfort on their body.

Although these physiological changes is the science of early puberty, but at this stage of life there are many common psychological change and development.In the early puberty, preadolescent and adolescent will begin to develop a strong sense of self.This typically includesChallenge the independenceLimit and strive for more privacy and the right to self-determination.

In other words, most people in the early puberty all want to choose for yourself.This includes determine their costumes, food, and the decoration of the room.As early adolescent self stereotypes more and more significantly, they often show black and white way of thinking.

Middle adolescence (14 to 17) :Due to schedule is the growth of each person is different, so the early, middle and late adolescence there is no clear line between.Some development model, however, are still common.For example, girls are usually in the early puberty will enter the fierce long-term, and many boys won't begin until the mid adolescence.From the point of view of body development, most of the mid adolescence can be described as "more same model".

In the middle of the adolescent, adolescents with fastCognitive development.Although the brain is fully developed in the next few years, but some brain functions, such as logical reasoning, will mature at the age of 16.This represents teenagers have as adults of logical reasoning ability.(if their logical thinking ability into rational behavior is another.)

Adolescence is also many teenagers begin to explore period of romantic relationships.It will usually take the form of a date.Teenagers may also start to ask and to explore their sexual orientation, in order to create and understand their own gender identity.

All these changes have close relationship with adolescent desire for independence, and this desire is usually accompanied by the growth of the age and more intense.For teenagers in the United States, a driver's license is the ultimate to mid adolescence keys (pun intended) in the form of independence.

Late adolescence (18 to 21 years old) :If you are looking for adolescent contain across 21 surprised, please don't worry - you may not be the only one!Teenagers legitimate as adults at the age of 18, so people tend to think that this is the end of the adolescence.However, in terms of development and growth, the human will to a certain stage of the 20 s to reach adulthood.

In the late adolescence, most of your body development all over, so at this stage mainly cognitive development.Youngsters made infamous for adventurous, but as the growth of the age, their ability of foresight will progress.The power loss in the growth of the brain.

The prefrontal cortex is the final stage of brain development, to the late adolescence will reach the adult form;And the prefrontal cortex is also responsible for decision-making and other key operations.(it is important to note the brain is still developing in this phaseMost of theIt will be fully developed at the age of 25 or 26.)

In the final stages of adolescence, early start for the development of trust, identity and values have become more stable.And, of course, they may be changed by experience, but when you transition to adulthood, the cognition of self consciousness and you can be key to return to self.

What is adulthood and how do we recognize adolescence has officially end?

Children and teenagers want to grow up.The yan out of a problem that there is no simple answer: what is an adult?You ask any adult may not be one of the most powerful answer directly.In order to法律的角度来说，在美国任何 18 岁以上的人都是成年人。但是，如上所述，从发展的角度来看，这个界限没有多大意义。

So how do we draw the boundaries between adolescence and adulthood?

When we to 22 years old, the body grow almost complete.Your bones(in addition to the clavicle, they do not fully developed until the mid early 30 s completely) is the size of your adult life back.Wisdom teeth are long over, your brain is complete the final phase of the prefrontal cortex.

From this period of time to middle age, your body will work with the best physical performance.Body that does not mean that it will be your life the best state, but it does represent your heart, lung, muscle and other organs will take the most efficient and the most powerful way.

Adulthood with the physiological development, brings the development of a series of new challenges: as a young adult, you will affect the social, emotional, and the rest of my lifeLiving habits.Sound pressure is not big?

Don't worry, these changes will not happen in the night of the evening.You won't be in a day from juvenile to mature adults.This is a gradual process.For this reason, many of the scientists define the life of the development of the new intermediate stage: the early adulthood or into early period.

What is the issue into early show:Early into a significant period is researcher describe terms in the transitional stage between adolescence and adulthood.It is not a stage of development, but it is a period of social and emotional exploration and growth.Early into a significant period is many young people began to explore all kinds of work, set up their first serious relationship and harness "adulthood" brings a series of new challenges.(these challenges including independent life, looking for a career, and in some cases to be a parent or spouse.)

As a result of this phase is different from person to person, make sure a clear dividing line into a significant period in early age almost impossible.Some people may enter adulthood at the age of 25, while others still struggled to establish himself at the age of 20 adult identity;That is to say, we can't use exact science to describe adult.

Back to begin this article put forward question: what is the definition of adults?In other words, what is maturity?So far, you have two ways to answer this question.You can from the point of view of human development or from the perspective of social and emotional.

The former provides a more definitive answer: adult period began in about 22 years old, the characterization of the physical development of adolescence has been completed.But as mentioned above, the answer is not satisfying, and provide only snippets of information;The most important of all, it did not identify the adulthooddefine.

In order to more comprehensive understanding of adulthood, you also need to consider social factors.Work is part of the adult?Independent life?In stable relationships?You must find their own answers to these questions.

So, what is maturity?Sometimes the best answer ", but inseparable."

Middle age: life isn't going downhill from now on

Show period into early may be a simulation of the ambiguous and difficult to define life stage, but middle age boundary is less clear.Middle-aged period starting from the age of 40, to the end of the 65 - year - old - between the two will be in accordance with the situation of plus or minus a few years time.

In this period, the lives of many people has been stabilized.Reached middle age, you will most likely have stable careers or into the professional field, satisfied with your beliefs and values, andMaintained a long-term and stable relationship and friendship.If the period of early adulthood is to explore and discover self, then the middle age is settled and stable phase.

When you close and middle-aged period, you may often find myself thinking, "I'm not as young as I was before" - the idea especially in sports.People tend to achieve physical peak in early adulthood.Since then, the loss of your body will become more obvious.This is the natural aging process,

And in several ways: you may find yourself injured recover much slower, or physical strength is not good.In addition, some health risk becomes higher in midlife.Screening for these diseases is helpful to early detection, early detection is a key part of the treatment.After 40 years old, should start screening of high blood pressure, diabetes and heart disease.If you are female, you can also screening for breast cancer and cervical cancer;If you are a man, can do the inspection of prostate cancer.

Although these screening sounds boring, but life is not start going downhill from here.Research shows that happiness and life satisfaction between the ages of 45 to 50 will hit bottom -- when you step into middle age.From then on, the more you old, you may feel the joy and satisfaction.

In every stage of life to take care of your health

Each stage of the life with the unique challenges and joy.Therefore, whether you are eager to grow up of teenagers, adults hope back in time, please remember thatLive in the present.No matter your age, are responsible for your health.Make your life more healthy it is never too early or too late, and take time to enjoy the joy brought by the each life stage!

Aging is the natural phenomena of life.In our age of growth at the same time, we also gradually aging cells.Cell aging is a biological process, in fact, the simple fact that, so we should not be kept in the dark.

We can start from birth on the first day of the principle of the cell aging.In the cells divide, replication, and conduct their own specific functions, they also continuously in aging.And in the process of cell aging, the body has to take care of senescent cells is wonderful way, the new cells to replace them.

Why cell aging?In order to下是几项较为常见的原因：

• DNA damage
• By internal or external factors caused by oxidative stress
• Cell autophagyThe function of reducing

Please remember, the body and the topic of aging of cells is not lose face, we should not be avoided.This along the way, our body is not only in aging, it is also constantly loudly announced to the world we experience the wonderful life.

And cell aging is just part of their life tiny circulation, let us show respect to the aging cells, and learn more about this unique cellular aging process of all kinds of knowledge.

The definition and principle of cell aging

In the scientific literature, aging is the aging degradation.The cells aging also refers to the aging process.Is the cell size of aging often have larger cells than aging.Senescent cells are no longer in order to protect themselves from surrounding tissue incorrect or harmful copying errors and continue to split.Copy cells split into the aging process takes about six weeks.

DNA replicationIs the key in the process of cells in the recession.In order to maintain health and functional tissues and organs, tissues and organs in the cell must not contain any duplicate error.In the face of replication stop aging cells, our bodies have natural strain signal measure.While these measures of signals by the aging cells itself and the surrounding environment.

You understand the three common cause of the cell aging, now, let's explore various factors.

DNA damage

New cells are not so you don't need to worry about DNA damage.Store unique genetic information of all the chromosomes in the chromosomes have repeated sequences, representing the end of the chromosome, we call their telomeres.They can help keep the body copy of DNA when copying the reliability and validity.

However, when the cell aging, the human body each replication cycle and every cell division lost a fraction of the gene sequence and the end of a chromosome telomeres will slowly become shorter, and therefore more easily lead to the destruction or incorrect cell replication of DNA.

In order to keep the correctness of the gene sequences, the end of a chromosome telomeres in cell signal when should stop replication.If less telomere, gene transcription and cell division will be endless, leading to the risk of error cells to pile up.Our cells need to inform their telomeres: should retire.

Oxidative stress

It's not just a trigger cell aging another reason,Oxidative stressCan also be terminated cell replication.Cells in the environment factors of reactive oxygen species is DNA replication errors.The mutation in the genetic code of reactive oxygen species can cause cell and thus affect cell function and health for a long time.

In order to maintain the correctness of the cellular DNA, when the body to detect the presence of reactive oxygen species in the environment of cells, gene copy will be aborted.Because of reactive oxygen species and stop to copy the action of senescent cells is to protect ourselves, let the body from cells error breeding or genetic transcription errors.

Function of autophagy is reduced

If you remember the meaning of this scientific proprietary words, that you really great!Autophagy the literal translation is "eat myself."This simple word perfect describes the cellular function of autophagy.They are in the process of cell agingOrgans (cell) and toolsWill begin to degenerate.The cells may start slowly hoarding of waste, we need to clean it.Through their own digestion, autophagy is the way of cell removal after use and damage.

The specific organs in human body cell can collect damaged cell composition and decomposition.We are going to these organs are called lysosomes.Full of lysosomesDigestive enzymesTo remove the accumulation of waste composition in the cell.

Cell autophagy ability will decrease with age, let the cells on the composition and processing waste decomposition organs hoarding impeded, protein accumulation, leading to aging cells and cause the problem of DNA replication in the future.

When the cell cannot manage waste accumulation in the cell membrane, it will stop splitting and cause aging.

Cell apoptosisVs.Cell aging

If you are in cell aging done enough research on this topic, then you should find what we call "apoptosis" the phenomenon.This process of cells and cell aging is easy to cause confusion.Now let's identify will lead to the different situation of the two processes.

As we have just read, cell aging is the process of aging cells stop dividing.In order to prevent lead to gene transcription errors, senescent cells but not to copy, but it still can continue to the original cell function.Senescent cells are not dead cells, but compared to the younger, continued to replicate cells, their functions and efficiency slightly decreased.

Cell apoptosis is basically is about to die.In the process of DNA replication, some cells may be out of the content it should follow.Out of control of cell replication can lead to abnormal cell growth, resulting in not up to standard, the accumulation of harmful copy cells.To terminate this might open the floodgates of our cells have they will obey special self-destruct steps.

Older than cells apoptosis likely, but not all the apoptotic cells are immediately into self-destruction mode.When the cell apoptosis program, launched human cells can release all cells can effectively organize internal function and the product of protein, and lysis (since).Cell apoptosis is not bloody, however, cells in the process of apoptosis in nearby healthy cells around won't hurt.

The end, the cells aging termination of cell division, if can't stop the cell fission can cause the occurrence of apoptosis.Hope our information can help you to solve in the penetration of the mysteries about this topic and cell aging.

A healthy life and cell aging

Cell aging is a part of life.When our cells gradually aging, ready to retire, the body will be high ability of young cells to replace them.No matter in life or cell which one part in life, we all can use healthy habit of living cells and the bodyThe overall care.

We can't avoid cell aging, but we can protect the health of the cells, let them not to early retirement.Some activities can shorten telomere and cause premature aging cells.Want to protect healthy cells, then try to avoid the following:

• sunburn
• Tanning beds
• smoking
• Use of drugs
• obesity
• Too much pressure

Studies have shown that these habits (especially the sunburn and tanning beds) will enhance oxidative stress caused by reactive oxygen species.As we all know, reactive oxygen species is one of the causes of cell aging.

Support for a way to protect body cells is get into the habit of can help maintain a healthy cells.We all know that healthy habits can make us feel the body is to maintain the best condition.In life there are many can greatly promote cells healthy lifestyle and food choices.Take time to review the four important habits, andLearn how to maintain a healthy cells.

Also, don't forget to, the body and cell aging are normal.The second half of life was always supposed to be enjoy.Let us, therefore, to the body since birth has done all of the necessities and expressing gratitude and respect, celebrate the aging body.Do good to our body in the process of cell aging, avoid aging behavior of the cell, and a diet rich in antioxidants habits and other support cells healthy habit to maintain health.