The nervous system develops fastest; the reproductive system develops last

·From top to bottom (look up → walk)

·From near to far (from near end → far end)

·From coarse to fine (grasp everything → pick with fingertips)

·From simple to complex (doodle → draw people)

·From low level to advanced level (observation, feeling, recognition→memory, thinking, analysis, judgment)

·Definition: It is the total weight of various organs, tissues and body fluids in the body

Significance: It is the most easily obtained sensitive indicator that reflects the physical growth and nutritional status of children. It is an important basis for calculating drug dosage, infusion volume, etc. in pediatric clinical practice.

The law of weight growth: the younger you are, the faster the growth (the first 3 months is approximately equal to the weight gain in the next 9 months, and 1 year old is approximately equal to three times the weight at birth)

Estimating formula <6 months: weight (kg) = birth weight age in months × 0.7 7~12 months: weight (kg) = 6 months old × 0.25 2 years old to 12 years old: age × 2 8

Physiological weight loss

Definition: Refers to the vertical distance from the top of the head to the soles of the feet. Measure the length in the supine position for children under 3 years old, and measure the height in the standing position after 3 years of age.

The law of height growth: the younger you are, the faster you grow.

The average length is 50cm at birth and 65cm at 6 months. The average length is 75cm at 1 year old and 85cm at 2 years old. Steady growth after the age of 2, with an average growth of 5-7cm per year 2-12 years old: Height (cm) = age × 7 77cm

The vertical distance from the top of the head to the ischial tubercle is measured in the supine position under 3 years old and is called crown-hip length; after 3 years old, it is measured in the sitting position and is called sitting height.

Definition: The length along the upper edge of the eyebrow arch and around the head through the occipital tubercle is an important indicator of brain development and skull growth.

·At birth: average 34~35cm: 3 months: 40cm. 1 year old: 46cm. 2 years old: 48cm. 5 years old: 50cm. 15 years old, almost adult: 54-58cm

Definition: Refers to the length from the lower edge of the flat nipple through the lower edge of the scapula angle around the sternum, reflecting the development of the lungs and chest

·At birth: chest circumference < head circumference 1 to 2cm, average 32 to 33cm ·Around 1 year old: Bust circumference = head circumference ·After 1 year old: Bust > Head circumference .Before 2 years old, the abdominal circumference and chest circumference are approximately equal.

Definition: refers to the length around the upper arm along the midpoint of the line connecting the acromion and the olecranon of the ulna, reflecting the development level of the bones, muscles, subcutaneous fat and skin of the upper arm

The assessment criteria for children under 5 years old are: >13.5cm means good nutrition 12.5~13.5cm is medium nutrition <12.5cm means malnutrition