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Growth and development are important characteristics of children different from those of adults.Growth refers to the growth of the organs and systems of children,and the corresponding measurement value can be used to indicate the changes of their quantity.Development refers to the differentiation and functional maturity of cells,tissues and organs.Growth and development are closely related to each other.Growth is the material basis of development,and changes in the amount of growth can reflect the maturity of body organs and systems to a certain extent.
Growth and development,both in the overall speed and the order of organs and systems,has a certain pattern.
1.Growth and development are continuous and periodic Growth and development continue throughout childhood,but growth rates varied at different ages.For example,weight and length in first years after birth,especially in the first 3 months of the year increase rapidly.And first year is the first growth peak after birth; from the second year,the growth rate gradually slow down until adolescence when the growth becomes faster,and that is the second growth peak.
2.The systems and organs are unbalanced The order of development of human organs system follows certain rules.For example,the development of the nervous system is earlier and the brain develops rapidly in the 2 years after birth.The lymphatic system grows rapidly in childhood,reaches its peak before adolescence and then decreases gradually; the reproductive system develops later.Other organs,such as heart,liver,kidney,muscle and so on,are basically parallel to physical growth.
3.General law of growth and development Growth and development generally follow the law from top to bottom,from near to far,from coarse to fine,from low to advanced,from simple to complex.Take the rule of motor development after birth as an example: firstly raising the head followed by lifting up the chest,then sitting,standing and walking (from top to bottom); from arms to hands,from the legs to feet in activity (from near to far); from the whole palm grip to the finger picking up (from coarse to fine); first drawing a straight line followed by circles,graphics (from simple to complex); firstly watching,listening feeling and understanding things followed by memorizing,thinking,analyzing and judging (from low to complex).
4.Individual differences in growth and development The growth and development of children follow certain rules,but in a certain range,there are considerable individual differences since they are affected by genetic factors and environmental factors.Therefore,the children’s growth and development has a certain normal range.“Normal value” is not absolute,and must be considered in combination with individual factors to make the right judgments.
a.Genetic Factor Genetic factors in both parents determine the track,characteristics,potential or and tendency of children’s growth and development.Such as skin color,hair color and shape features,height,eugamic time,the nutrient needs and susceptibility to infectious disease,which are all influenced greatly by races,familial genetic information.Under abnormal conditions,genetic metabolic defect,endocrine disorders,chromosome abnormalities and other factors that affect growth are more directly related to heredity.
b.Maternal Factors Fetal development in uterus is influenced by intrauterine environment,nutrition,mood,disease and other factors of the mother.Viral infection of a mother in early pregnancy can lead to fetal congenital malformation; exposure to certain drugs,X-ray irradiation,poisons in environment and psychic trauma can postpone the fetal development; severe malnutrition of the mother can cause miscarriage,premature birth and delayed growth of fetal physique and brain.
a.Nutrition The growth and development of children need adequate nutrient supply.The proportion of nutrient supply is appropriate and the living environment is suitable,so that the growth potential can be best developed.Intrauterine malnutrition of fetus will delay the growth of physique,and severe malnutrition will also seriously affect the development of the brain; postnatal malnutrition,especially in the first two years,if serious,can affect children’s weight and height and intelligent development,and lower the functions of the body immune,endocrine,neural regulation.
b.Diseases The influence of diseases on growth and development is obvious.For example,acute infection often causes weight loss; chronic diseases affect weight and height development; endocrine diseases often delay the bone growth and nervous system development.
c.Environment The quality of living environment determines the condition of children’s growth and development to a certain extent.Good living environments,such as adequate sunshine and fresh air,clean water,no noise,comfortable living conditions,combined with good living habits,scientific care,good upbringing,physical exercise,comprehensive health care services,are important factors to promote the growth and development of children to the best.
The physical growth of children is often expressed by constants which is easy to measure and obtained from statistics of largescale measurements.
Weight is the total weight of a child’s body and is an important indicator of physical growth and nutritional status.In pediatric clinical practice,body weight is used as a basis for calculating the amount of heat,dosage,and amount of intravenous fluids.Weight should be measured in the early morning with an empty stomach,empty bowels and minimal clothing.
When the child was born,the body weight was about 3 kg,and the average monthly growth rate was about 0.7 kg in the first half of the year after birth.The average monthly growth rate was about 0.5 kg in the latter half of the year,and the average annual increase was about 2 kg after the age of 1.The body weight of normal children can be calculated by the following formulas:
≤ 6 months weight (kg) = 3 + 0.7 ×month of age
7–12 months weight (kg) = 7 + 0.5 ×(month of age – 6)
1–12 years weight (kg) = 8 + 2 ×years of age
There are some individual differences in the weight of children at the same age,and their fluctuation range is not more than 10%of the normal value.Abnormal excess weight gain may indicate obesity,and 15% of the weight loss above normal is classified as malnourished.
Height (length) refers to the vertical length from top to sole.Orthostatic measurement is called height.It is difficult to accurately measure the height of children under 3 years old in the standing position,so it is recommended to measure them in a supine position with a measuring bed.The difference between measurement value of standing and supine is about 1 cm.To measure,they should take off their shoes,socks and hats,and stand straight with eyes looking straight ahead,with heels,shoulders,back and hip firmly against the measuring ruler.
The growth rate of height is similar to that of weight.The younger the age,the faster it grows.The newborn’s length is about 50 cm.The most rapid growth period is during the first years of life,when it reaches about 25 cm.During the first three months,a newborn can gain almost 12 cm.During the second year,the body growth rate slowed down with a rate of about 10 cm.After 2 years of age to adolescence,height (length) grows steadily with a rate of about 7 cm per year.In adolescence,there is the second peak in height growth,and the rate is about two times that of school age,which lasts 2–3 years.The following formula can be used to calculate the height of children aged 2 to 12 years:
Height (cm) = 70 + 7 × years of age
Height (length) growth is related to race,heredity,constitution,nutrition,exercise,and diseases.The abnormal height is significant manifestations of diseases,for example,if the height is 70% lower than the normal average,dwarfism,cretinism,malnutrition should be considered.
In addition,the upper segment and lower segment can be measured.The former refers to the length from the top of the head to the upper edge of the pubic symphysis,and the latter refers to the length from the upper edge of the symphysis pubis to the sole.The upper segment is closely related to the growth of spine,and the lower segment is closely related to the growth of the long bone of lower limbs.Before the age of 12,the upper segment is greater than the lower one; after 12 years old,the lower segment is greater than the upper one.
Fontanelles are classified into anterior and posterior fontanelle.Anterior fontanelle is the diamond-shaped gap between the frontal and parietal,while posterior fontanelle is the triangle-shaped gap between the parietal and occipital.The size of the anterior fontanelle is represented by the length between the midpoints of the opposite sides and it is usually closed by 12–18 months old.For some children,the posterior fontanelle is closed at birth.For those that are open,the posterior fontanelle will close in 6–8 weeks.
Fontanelle can reflect the growth and development of the skull and has a certain significance to the diagnosis of certain diseases.If the fontanelle closes too early and the head circumference is less than normal,this is called microcephaly; if the fontanelle closes too late and the head circumference is greater than normal,this generally indicates the likelihood of metopism (hydrocephalus) or rickets.A sunken fontanelle is usually due to yin-fluid exhaustion or extreme emaciation.A bulging fontanelle usually reflects encephalitis or meningitis caused by intense heat in qi and nutrient aspects.
Head circumference refers to the length of a circle that starts at the upper edge of the eyebrow arch,passing the occipital bone nodules and going around the skull.A full-term infant’s head circumference is about 33–34 cm at birth.In the first 3 months after birth it gains 6 cm and another 6 cm during the following 9 months.The head circumference is about 46 cm at 1 year old,48 cm at 2,50 cm at 5,and 54–58 cm at 15 years old,approaching that of an adult.
Head circumference growth is related to the growth of the brain and the skull.The small head circumference is suggestive of cerebral hypoplasia.An excessive increase in head circumference indicates the metopism(hydrocephalus).
The size of the chest circumference is related to the growth and development of the lung and the thorax.To measure the chest circumference,children under 3 years of age should be allowed to stand or lie down.For children over 3,erect posture is preferred.The children should be in a quiet state,hands down naturally or flat (supine),eyes looking straight ahead.The measurer stands to the right,in front of the child.Circle the measuring tape from the nipple to the lower edge of scapulae and return to the nipple.Record the average value of the measurements during exhalation and inhalation.When measuring,the tape should not be too tight or too loose;the symmetry between bilateral and sagittal aspects needs to be maintained.
The newborn’s chest circumference is about 32 cm; about 44 cm at 1 year old,approaching the head circumference and gradually exceeding the head circumference after 2 years of age.Generally the chest circumference occurs later than the head circumference in children with malnutrition or lack of exercise which leads to a slow increase and poor development of the thorax,otherwise,the time when chest circumference exceeds head circumference occurs earlier among well-nourished children.
Humans have two sets of teeth in life,namely,deciduous teeth (20) and permanent teeth (28–32).Primary teeth erupt during 4–10 months after the birth.The teething order is from the lower jaw to upper jaw and from the front to the back,except the canine teeth.All the primary teeth erupt and become visible at about 2–2.5 years of age.At around 6,the first eruption of the permanent tooth appears.From age 7–8 year,the primary teeth fall out one by one in the order of eruption priority and are replaced by permanent teeth.The past permanent tooth (the third molar)usually erupts between 20–30 years of age but it may never appear for some people during their lifetime.
By the age of 2,the number of primary teeth can be calculated according to the following formula:
Number of primary teeth = month of age – 4(or 6)
The growth of teeth is related to the growth of bone,but not entirely parallel.Delays in teeth eruption or teething in a disordered sequence are common in rickets,cretinism,and malnutrition,etc.
Respiration and pulse examination should be performed when children are quiet.The younger they are,the faster the breath and pulse.The normal values of children’s breathing and pulse in each age group are shown in table 3–1.
Table 3–1 Breathing and Pulse Frequencies in Each Age Group
Choose cuffs in different widths for different age groups to measure the blood pressure.The cuff width should be 2/3 of the upper arm length.If the cuff is too wide,the measured blood pressure will be lower than the actual blood pressure.If the cuff is too narrow,the measurement will higher.In children,the younger,the lower.Children’s blood pressure in different age groups can be calculated according to the following formulas:
Systolic pressure (mmHg) = 80 + 2 × age
Diastolic pressure (mmHg) = Systolic pressure × 2/3
a.Visual perception
The newborn has visual sensing function,but not sharp,and can only see objects within 15 to 20 cm.During the 2nd month,infants begin to coordinate their eyes and head together and can focus on an object.During the 3rd month,infants are able to track moving objects or a person with improved eyehead coordination.From the 4th to 5th month,infants begin to recognize their mother and show signs of happiness at the sight of a feeding bottle.At 6th month,infants are able to turn around and coordinate their eyes.At 9 months,visual depth perception develops and infants can see small objects.At 1.5 years old,they are able to distinguish different shapes.At 5 years old,they can distinguish different colors.At the age of 6,the visual depth perception has been fully developed.
b.Auditory perception
An infant’s auditory apparatus is functional at birth and hearing is quite good during the first 3–7 days after birth.At the 3rd month,they are able to turn the head towards the sound; at the 4th month,they will smile at pleasant sounds; at 8th month,they are able to distinguish between simple language meanings; at 9th month,they are able to seek and locate the source of sounds from different directions; the auditory development becomes mature at the age of 4.
c.Smell and taste
The senses of smell and taste are basically mature at birth.They are able to react to breast milk flavor,and have different response to different tastes,such as sweet,sour and bitter and so on; during 3–4 months they can distinguish pleasant and unpleasant smells; at the 5th month,infants are sensitive to tiny changes of a taste,when many different kinds of food should be supplemented to their diet for them to adapt to different tastes.
d.Skin sense perception
The newborn is very sensitive to touches,especially on the lips,palms,feet,forehead and eyelids; pain is present at birth and can cause systemic or local reactions; temperature sensation is also very sensitive,especially to cold.At the age of 2–3,children can distinguish objects big or small,hard or soft,hot or cold,and so on through touch and hand-eye coordinated activities.At 5 years old,children are able to tell objects of the same size but different weights.
e.Perception
Perception is a comprehensive reflection of human beings and is closely related to the development of the above sensory abilities.The infant begins to develop space and time perception by the end of the first year; at 3 years old,children are able to distinguish up and down directions; at about 4 years old,children can identify the front and the back,and begin to understand time concepts; at 5 years old,children are able to recognize their left and right sides.
The development of motor skills in children is from top to bottom,from gross to fine,from uncoordinated to coordinated progress.
a.Balance and gross motor skills
Newborns at prone position are able to raise their heads for 1 to 2 seconds; at 2 months old,they are able to sit up with help and manage to hold their heads up while lying on their sides; at 4 months,to look up stably and hold up the upper body; at 6 months,to sit alone for a while; at 8 months,to crawl; at 10 months,to walk with support;at 12 months,to walk on their own; at 18 months,to run and walk backward; at 24 months,to jump; and at 30 months,they are able to hop.
b.Fine motor skills
Infants can play with their own hands and attempt to grasp things at 3–4 months of age;at 5 months,they co-ordinate their hand-eye movements and consciously grab items in front of them; at 5–7 months,they begin changing hands,kneading,knocking and other exploratory movements; at 9–10 months,they can pick things with the thumb and index fingers,and love tearing paper; at 12–15 months,they learn to use the spoon and scribble; at the age of 2 they can roughly turn the pages and at 3 years old,they can put on simple clothes.
The development of language involves 3 stages: pronunciation,comprehension and expression.The newborns are already able to cry; at 2 months,they can produce harmonious guttural sounds; at 3 months,babbling sounds; at 4 months,laughs; at 7–8 months,double sounds,such as “mama” and “papa”;at 1 year old,some simple expressions of life,such as eating,walking and holding; after the age of 2,they can simply talk and can express himself in a complete language after the age of 5.
People’s psychological activities include sensation,memory,thought,imagination,emotion,character and so on.The newborns do not have psychological phenomenon,but once conditioned reflex is formed,it marks the beginning of psychological activity development,and with the growth of age,it will be in constant development process.
The newborns already have nonconditional reflex.For example,talking loudly can stop their activities,and they will respond to hunger,discomfort and cold with restless,weeping and crying and other negative emotions;at 2 months,the positive emotions are increasing,and they will especially happy when seeing the mother; at 3 months,they are able to pay short attention to the face and the voice; at 5–6 months,babies can recognize mother and other familiar people,but there will be no reproduction until after 1 year old.
The ability of recognition during infancy is further enhanced and they are able to recognize things after dozens of days or months at the end of their infancy,and the emotional expressions in children are increasingly rich and complex; preschool children are able to consciously control the manifestations of their emotions,and to memorize what interests them and what evokes strong emotional experience for a long time; for school-age children,because of the development of analyzing and thinking ability and the requirement of learning tasks,their memory ability is reinforcing,the content of memory is broadening,and the complexity increasing.After 5–6 years of age they can better control their attention; after 11–12 years old,the concentration and stability of children’s attention are improving,and the scope of attention is also expanding.
Ancient Chinese medicine physicians used Biàn Zhēng theory to explain the regular patterns of growth and development in children and to expound the physiological phenomena during their growth and development. Biàn means changes (intelligence changes) and enlightening of the mind while Zhēng means steady growth of blood vessels and bones.Young children grow rapidly with continuous changes in mind and body,progressing day by day,which is therefore called Biàn Zhēng .
The number of days of Biàn Zhēng is determined by the date of birth: the first 32 days after birth is called a Biàn ; 64 days is called the next Biàn,and also a Zhēng ; that is,two Biàn equals one Zhēng .320 days consist of ten Biàn and five small Zhēng .After a total of five small Zhēng are followed by the large Zhēng interval of 64 days,and followed by a double large Zhēng interval of another 64 days,then the double large Zhēng are repeated with intervals of 128 days.That is a total of three large Zhēng within 256 days.So,there are 320 days of small Zhēng and 256 days of large Zhēng ,totaling 576 days,so Biàn Zhēng finishes around one year and seven months.During the process,a child’s body grows and develops continuously and the functions of zang-fu organs are maturating and improving gradually,thus the children’s body and mind is developing coordinately.
Biàn Zhēng theory sums up the patterns of growth and development in young children:the infants grow and develop most rapidly in the infant period; the growth and development is a continuous process of changes; after a certain period of time there are significant changes in growth and development; during the periodic significant changes,the body and the mind are developing appropriately and synchronously; the cycle of Biàn Zhēng is gradually extended,indicating that the growth and development in young children gradually slow down with age; there is no Biàn Zhēng after a certain time(576 days) and their growth and development tend to be slow.The principle of the development of young children revealed by the theory is consistent with reality and has an important reference value for us to understand the characteristics of children’s growth and development and to study the law of the growth and development of contemporary children.