developmental adj : of or relating to or constituting development; "developmental psychology"
- Related to how development occurs.
- Developmental psychology studies how the mind forms as children grow.
Human development is the process of growing to maturity. In biological terms, this entails growth from a one-celled zygote to an adult human being.
Development begins with fertilization, the process by which the male gamete, the sperm cell, and the female gamete, the oocyte, fuse to give rise to a diploid cell, the zygote. In pregnancy the 3 stages are commonly referred to as ZEF - meaning Zygote, Embryo, Fetus.
In medicine, pregnancy is defined as beginning when a fertilized zygote becomes implanted in a woman's uterus. This occurs when the zygote then becomes embedded into the endometrium (lining of the uterus) where it forms a placenta, for the purpose of receiving essential nutrients through the uterus wall. The umbilical cord in a newborn child signifies the remnants of implantation.
The zygote undergoes rapid mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of an embryo.
Childbirth is the process in which the baby is born. It is considered by many to be the beginning of a person's life, where age is defined relative to this event in most cultures.
Terms for stages of age-related physical development include, with their approximate age ranges:
(fertilisation - birth)
- Embryo - (fertilisation - 8 weeks of gestational phase)
- Fetus (8 weeks of gestational phase - birth)
age of majority)
- Neonate (newborn) (0-30 days)
- Infant (baby) (1 month-1 year)
- Toddler (1-4)
- Play age (3 - 6 years)
- Primary school age (also called prepubescence) (4-11)
- Adolescence and puberty (teenage) (12-19)
- Adult (20-death)
- Prenatal (fertilisation - birth)
(occurs at various ages, depending on person)
- Decomposition (breakdown of the body after death)
Also sometimes used are terms that specify one's age in numbers, such as:
- Child (0-11)
- Teenager (11-19)
- Twentysomething (20-29)
- Thirtysomething (30-39)
- Fortysomething (40-49) (formerly also Quadragenarian, rarely used since 1980)
- Quinquagenarian (50-59)
- Sexagenarian (60-69)
- Septuagenarian (70-79)
- Octogenarian (80-89)
- Nonagenarian (90-99)
- Centenarian (100-109)
- Supercentenarian (110+)
Physical development milestones
Note: the Tanner stages can be used to approximately judge a child's age based on physical development.
developmental in Spanish: Crecimiento humano
developmental in French: Développement humain (biologie)
developmental in Indonesian: Tahap perkembangan manusia
developmental in Italian: Sviluppo umano (biologia)
developmental in Dutch: Levensfase
developmental in Polish: Okresy rozwojowe człowieka