Search results
Development of the human body is the process of growth to maturity. The process begins with fertilization, where an egg released from the ovary of a female is penetrated by a sperm cell from a male. The resulting zygote develops through mitosis and cell differentiation, and the resulting embryo then implants in the uterus, where the embryo ...
- Overview
- Types and rates of human growth
human development, the process of growth and change that takes place between birth and maturity.
Human growth is far from being a simple and uniform process of becoming taller or larger. As a child gets bigger, there are changes in shape and in tissue composition and distribution. In the newborn infant the head represents about a quarter of the total length; in the adult it represents about one-seventh. In the newborn infant the muscles constitute a much smaller percentage of the total body mass than in the young adult. In most tissues, growth consists both of the formation of new cells and the packing in of more protein or other material into cells already present; early in development cell division predominates and later cell filling.
Different tissues and different regions of the body mature at different rates, and the growth and development of a child consists of a highly complex series of changes. It is like the weaving of a cloth whose pattern never repeats itself. The underlying threads, each coming off its reel at its own rhythm, interact with one another continuously, in a manner always highly regulated and controlled. The fundamental questions of growth relate to these processes of regulation, to the program that controls the loom, a subject as yet little understood. Meanwhile, height is in most circumstances the best single index of growth, being a measure of a single tissue (that of the skeleton; weight is a mixture of all tissues, and this makes it a less useful parameter in a long-term following of a child’s growth). In this section, the height curves of girls and boys are considered in the three chief phases of growth; that is (briefly) from conception to birth, from birth until puberty, and during puberty. Also described are the ways in which other organs and tissues, such as fat, lymphoid tissue, and the brain, differ from height in their growth curves. There is a brief discussion of some of the problems that beset the investigator in gathering and analyzing data about growth of children, of the genetic and environmental factors that affect rate of growth and final size, and of the way hormones act at the various phases of the growth process. Lastly, there is a brief look at disorders of growth. Throughout, the emphasis is on ways in which individuals differ in their rates of growth and development.
The changes in height of the developing child can be thought of in two different ways: the height attained at successive ages and the increments in height from one age to the next, expressed as rate of growth per year. If growth is thought of as a form of motion, the height attained at successive ages can be considered the distance travelled, and the rate of growth, the velocity. The velocity or rate of growth reflects the child’s state at any particular time better than does the height attained, which depends largely on how much the child has grown in all preceding years. The blood and tissue concentrations of those substances whose amounts change with age are thus more likely to run parallel to the velocity rather than to the distance curve. In some circumstances, indeed, it is the acceleration rather than the velocity curve that best reflects physiological events.
Britannica Quiz
Characteristics of the Human Body
In general, the velocity of growth decreases from birth onward (and actually from as early as the fourth month of fetal life; see below), but this decrease is interrupted shortly before the end of the growth period. At this time, in boys from about 13 to 15 years, there is marked acceleration of growth, called the adolescent growth spurt. From birth until age four or five, the rate of growth in height declines rapidly, and then the decline, or deceleration, gets gradually less, so that in some children the velocity is practically constant from five or six up to the beginning of the adolescent spurt. A slight increase in velocity is sometimes said to occur between about six and eight years.
This general velocity curve of growth in height begins a considerable time before birth. The peak velocity of length is reached at about four months after the mother’s last menstruation. (Age in the fetal period is usually reckoned from the first day of the last menstrual period, an average of two weeks before actual fertilization, but, as a rule, the only locatable landmark.)
Figure 1. Human development encompasses the physical, cognitive, and psychosocial changes that occur throughout a lifetime. Human development refers to the physical, cognitive, and psychosocial development of humans throughout the lifespan. What types of development are involved in each of these three domains, or areas, of life?
Oct 11, 2022 · 12.2: Germinal Stage. The germinal stage of development is the first and shortest of the stages of the human lifespan. The main events in this stage of development are illustrated in the figure below and described in detail in the rest of this concept. The germinal stage lasts a total of eight to nine days. It begins in a Fallopian tube when an ...
Mar 8, 2023 · In the context of childhood development, growth is defined as an irreversible constant increase in size, and development is defined as growth in psychomotor capacity. Both processes are highly dependent on genetic, nutritional, and environmental factors. Evaluation of growth and development is a crucial element in the physical examination of a patient. A piece of good working knowledge and the ...
- Palanikumar Balasundaram, Indirapriya Darshini Avulakunta
- 2023/03/08
- 2021
Physical development involves growth and changes in the body and brain, the senses, motor skills, and health and wellness. Cognitive development involves learning, attention, memory, language, thinking, reasoning, and creativity. Psychosocial development involves emotions, personality, and social relationships.
People also ask
What is the process of development of the human body?
What is human development?
How do human organs develop?
What are the phases of human growth and development?
What is human embryonic development?
Aug 24, 2018 · The six life processes in human beings are: growth and development, movement and responding to stimuli, order and organization, reproduction and heredity, energy utilization and homeostasis. All living things exhibit these processes, but some scientists arrange or label these processes differently.
