Normal development age

The development of our body is a gradual process, and the age at which each organ develops is different. Normal developmental age is divided into stages, and there will be different changes in each period. The growth of children is what parents care about most. If any abnormalities occur, they must be resolved in a timely manner to avoid lifelong impacts. It is necessary to have a full understanding of the different characteristics of normal developmental ages in advance. Let’s take a look below.

Different age groups have different physiological and anatomical characteristics. According to the characteristics of growth and development in each period, it is generally divided into the following stages. However, growth and development is a continuous process. There are no strict boundaries between the stages, and they are closely related to each other.

Embryonic development

The embryonic development period is from the combination of egg and sperm to 8 weeks, when various tissues, organs, and systems rapidly differentiate and develop and begin to take on a human form. This period is a very important period for children's growth and development. If the development is hindered by internal and external factors, it may lead to various congenital malformations.

The fetal period is from 8 weeks to birth, during which various organs further enlarge, develop gradually and complete, and the fetus grows rapidly.

The infancy period is the period from birth to one year old, also known as the suckling period. This period is the period of fastest growth and development for children after birth, so the calories and nutrients they need to consume, especially protein, are particularly high. They mainly obtain nutrition from milk. Their physique grows rapidly, with their height increasing by about 50% and their weight increasing by about 2 times in a year compared to when they were born. Their brain also develops rapidly. At one year old, the baby's motor skills are such that he can sit, crawl and start to learn to walk. The process of gross motor development can be summarized as: "Two lifts, four flips, six sits, seven rolls, eight crawls, and then walks."

Early childhood

The early childhood period is from one year old to three years old. The development speed during this period is slower than before, especially in physical development. During this period, the anterior brim closes and the deciduous teeth come out completely. Nervous system development begins to slow down, and the brain reaches 80% of its adult size. The range of activities gradually widens, they come into contact with more things around them, their intelligence develops more prominently than before, and their language, thinking and ability to respond to people and things are enhanced.

School age

The period from entering primary school (6-7 years old) to the onset of puberty (12 years old for girls and 13 years old for boys) is called school age. Physical development continues to grow steadily during this period, and the development of organs other than the reproductive system is close to adult levels by the end of this period. The morphology of the brain is basically the same as that of an adult, the intelligence is more mature than before, and the ability to control, understand, analyze, and integrate is enhanced. The development of the lymphatic system is at its peak. Generally, by the age of 12, all the deciduous teeth have fallen out and all permanent teeth except the third molars have grown out.

puberty

Puberty is the period from 11-12 years old to 17-18 years old for girls and from 13-14 years old to 18-20 years old for boys, but there are large individual differences, sometimes with a difference of 2-4 years. The characteristics of this period are that growth and development are significantly accelerated under the action of sex hormones, the increase in weight and height increases, secondary sexual characteristics gradually become obvious, and the reproductive organs develop rapidly and tend to mature. At this time, due to the unstable nervous and endocrine regulation, psychological, behavioral, and mental instability often occurs; on the other hand, due to increased contact with society and encountering many new problems, the external environment has an increasingly greater impact. According to developmental characteristics, puberty is divided into:

(1) Prepuberty: refers to the stage of rapid growth and development before the first menstruation in girls or the first nocturnal emission in boys, which usually lasts about 2-3 years.

(ii) Mid-puberty: refers to the 3-4 years after the start of development of secondary sexual characteristics, also known as the sexual characteristics development period. This period is characterized by the development of sexual characteristics.

(iii) Late puberty: refers to the stage from the development of secondary sexual characteristics to adulthood to the cessation of physical development. It usually lasts about 3 years.