what is meant by annual growth of human development?
Answers
Answer:
In the context of the physical development of children, growth refers to the increase in the size of a child, and development refers to the process by which the child develops his or her psychomotor skills.
Human growth and development
Definition
In the context of the physical development of children, growth refers to the increase in the size of a child, and development refers to the process by which the child develops his or her psychomotor skills.
Description
Growth
The period of human growth from birth to adolescence is commonly divided into the following stages:
Infancy: From birth to weaning.
Childhood: From weaning to the end of brain growth.
Juvenile: From the end of childhood to adolescence.
Adolescence: From the start of growth spurt at puberty until sexual maturity.
Growth curves are used to measure growth. The distance curve is a measure of size over time; it records height as a function of age and gets higher with age. The velocity curve measures the rate of growth at a given time for a particular body feature (such as height or weight). The height velocity curve is highest in infancy, up to two years of age, with more consistent annual growth afterwards and increases again at puberty. The height of the average infant increases by 30% by the age of five months and by 50% by the age of one year. The height of a five-year-old usually doubles relative to that at birth. The limbs and arms grow faster than the trunk, so that body proportions undergo marked variation as an infant grows into an adolescent. Different body systems grow and develop at different rates. For example, if infants grew in height as quickly as they do in weight, the average one-year-old would be approximately 5 ft (1.5m) tall. Thus, weight increases faster than height—an average infant doubles his birth weight by the age of five months and triples it by the age of one year. At two years of age, the weight is usually four times the weight at birth.
Physical development
During the growth period, all major body systems also mature. The major changes occur in the following systems:
Skeletal system. At birth, there is very little bone mass in the infant body, the bones are softer (cartilagenous) and much more flexible than in the adult. The adult skeleton consists of 206 bones joined to ligaments and tendons. It provides support for the attached muscles and the soft tissues of the body. Babies are born with 270 soft bones that eventually fuse together by the age of 20 into the 206 hard, adult bones.
Lymphatic system . The lymphatic system has several functions. It acts as the body's defense mechanism by producing white blood cells and specialized cells (antibodies) that destroy foreign organisms that cause disease. It grows at a constant and rapid rate throughout childhood, reaching maturity just before puberty. The amount of lymphatic tissue then decreases so that an adult has approximately 50% less than a child.
Central nervous system (CNS). The CNS consists of the brain, the cranial nerves, and the spinal cord . It develops mostly during the first years of life. Although brain cell formation is almost complete before birth, brain maturation continues after birth. The brain of the newborn is not yet fully developed. It contains about 100 billion brain cells that have yet to be connected into functioning networks. But brain development up to age one is more rapid and extensive than was previously realized. At birth, the brain of the infant is 25% of the adult size. At the age of one year, the brain has grown to 75% of its adult size and to 80% by age three, reaching 90% by age seven. The influence of the early environment on brain development is crucial. Infants exposed to good nutrition , toys, and playmates have better brain function at age 12 than those raised in a less stimulating environment.
Psychomotor development
During the first year of life, a baby goes through a series of crucial stages to develop physical coordination. This development usually proceeds cephalocaudally, that is from head to toe. For example, the visual system reaches maturity earlier than do the legs. First, the infant develops control of the head, then of the trunk (sitting up), then of the body (standing), and, finally, of the legs (walking). Development also proceeds proximodistally, that is from the center of the body outward. For example, the head and trunk of the body develop before the arms and legs, and infants learn to control their neck muscles before they learn to direct their limbs. This development of physical coordination is also referred to as motor development and it occurs together with cognitive development, meaning the development of processes such