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Encyclopedia > Human development (biology)

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. In psychology, Human development is the study of mental and related processes across the life span. ... Image File history File links Question_book-3. ... In biology growth is increase in size. ... It has been suggested that Biparental zygote be merged into this article or section. ... Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ...

Contents

Biological development

A spermatozoon fertilizing an ovum
A spermatozoon fertilizing an ovum

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. Image File history File links Sperm-egg. ... Image File history File links Sperm-egg. ... Categories: Biology stubs ... A gamete (from Ancient Greek γαμετης; translated gamete = wife, gametes = husband) is a cell that fuses with another gamete during fertilization (conception) in organisms that reproduce sexually. ... A spermatozoon or spermatozoan ( spermatozoa), from the ancient Greek σπέρμα (seed) and (living being) and more commonly known as a sperm cell, is the haploid cell that is the male gamete. ... An oocyte or ovocyte is a female gametocyte or germ cell involved in reproduction. ... Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the...


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. It has been suggested that Biparental zygote be merged into this article or section. ... Implantation is a phenomenon in prenatal development, i. ... This article is about female reproductive anatomy. ... The endometrium is the inner membrane of the mammalian uterus. ... The placenta (Latin for cake, referencing its appearance in humans) is an ephemeral organ present in placental vertebrates, such as eutherial mammals and sharks during gestation (pregnancy). ... Nutrients and the body A nutrient is any element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ... This article is about female reproductive anatomy. ... In placental mammals, the umbilical cord is a tube that connects a developing embryo or fetus to the placenta. ...


The zygote undergoes rapid mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of an embryo. Mitosis divides genetic information during cell division. ... This does not adequately cite its references or sources. ... In embryology, cleavage is the division of cells in the early embryo. ... Embryonic stem cells differentiate into cells in various body organs. ... For other uses, see Embryo (disambiguation). ...



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. Parturition redirects here. ...


Physical stages

Terms for stages of age-related physical development include, with their approximate age ranges:

Also sometimes used are terms that specify one's age in numbers, such as: This article is about life in general. ... This article is about prenatal development in humans. ... Human embryogenesis is the process of cell division and cellular differentiation of the human embryo during early prenatal development. ... It has been suggested that Biparental zygote be merged into this article or section. ... The term conception can refer to more than one meaning: Concept Fertilisation This is a disambiguation page — a navigational aid which lists pages that might otherwise share the same title. ... The blastocyst is an early stage of the human (or any other mammal) development early in pregnancy. ... For other uses, see Embryo (disambiguation). ... For other uses, see Fetus (disambiguation). ... For other uses, see Child (disambiguation). ... Parturition redirects here. ... “Baby” redirects here. ... Boy toddler Toddler is a common term for a a young child who is learning to walk or toddle,[1] generally considered to be the second stage of development after infancy and occurring predominantly during the ages of 12 to 36 months old. ... A primary school in Český Těšín, Czech Republic. ... Primary or elementary education is the first years of formal, structured education that occurs during childhood. ... A separate article is about the punk band called The Adolescents. ... Teen redirects here. ... For the adult insect stage, see Imago. ... The general term Young adult refers to different age groups based on context: In popular usage, young adult is a euphemism for an adolescent. ... The term adult describes any mature organism, but normally it refers to a human: one that is no longer a child / minor and is now either a man or a woman. ... Middle age is the period of life beyond young adulthood but before the onset of old age. ... Old age consists of ages nearing the average lifespan of human beings, and thus the end of the human life cycle. ... Old age consists of ages nearing the average lifespan of human beings, and thus the end of the human life cycle. ... For other uses, see Death (disambiguation). ... For other uses, see Decomposition (disambiguation). ...

  • Child (0-12)
  • Teenager (13-19)
  • 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+)
Comparison table
years[1]
Child prenatal >0
infancy 0 - walking
toddlerhood walking - 3
play age 3-6
preadolescence 10 - puberty
adolescence puberty - 19
Young adult twentysomething 20-29
thirtysomething 30-39
Middle age fortysomething 40-49
quinquagenarian 50-59
Advanced adult sexagenarian 60-69
septuagenarian 70-79
octogenarian 80-89
nonagenarian 90-99
centenarian 100-109
supercentenarian 110

A twentysomething is a person in the age group of 20 to 29. ... The term thirtysomething was initially introduced during the 1980s to describe a person of the baby boom generation, born during the 1940s and 1950s. ... A fortysomething (or forty-something) is a person aged between 40 and 49 years. ... A fiftysomething (or fifty-something) is a person aged between 50 and 59 years. ... A centenarian is a person who has attained the age of 100 years or more. ... A supercentenarian (sometimes hyphenated as super-centenarian) is someone who has reached the age of 110 years or more, something achieved by only one in a thousand centenarians (based on European data). ... For other uses, see Child (disambiguation). ... Prenatal means before birth (is widely used in biology). ... A human infant The word Infant derives from the Latin in-fans, meaning unable to speak. ... A separate article is about the punk band called The Adolescents. ... Puberty refers to the process of physical changes by which a childs body becomes an adult body capable of reproduction. ... Teen redirects here. ... The general term Young adult refers to different age groups based on context: In popular usage, young adult is a euphemism for an adolescent. ... Twentysomething is the third album by Jamie Cullum. ... thirtysomething (1987 – 1991) was a ground-breaking and award-winning American evening television drama, of the type popularly labeled a soap opera when broadcast during the daytime. ... Middle age is the period of life beyond young adulthood but before the onset of old age. ... A fortysomething (or forty-something) is a person aged between 40 and 49 years. ... A quinquagenarian is a person in the age group 50 to 59 years old. ... Old age consists of ages nearing the average lifespan of human beings, and thus the end of the human life cycle. ... A sexagenarian is a person in the age group of 60 to 69 years old. ...

Physical development milestones

Note: the Tanner stages can be used to approximately judge a child's age based on physical development. This page is a candidate to be copied to Wiktionary. ... This article does not cite any references or sources. ... Bold text This article does not cite any references or sources. ... The human voice consists of sound made by a human using the vocal folds for talking, singing, laughing, crying and screaming. ... Pubic hair is hair in the frontal genital area, the crotch, and sometimes at the top of the inside of the legs; these areas form the pubic region. ... A sex organ, or primary sexual characteristic, narrowly defined, is any of those parts of the body (which are not always bodily organs according to the strict definition) which are involved in sexual reproduction and constitute the reproductive system in an complex organism; namely: Male: penis (notably the glans penis... The menstrual cycle is the periodic change in a womans body that occurs every month between puberty and menopause and that relates to reproduction. ... Hair is also a musical: see Hair (musical) and Hair (movie) Hair is the filamentous outgrowth of the epidermis found in mammals. ... One kind of modern beard. ... The Tanner stages (also known as the Tanner scale) are stages of physical development in children, adolescents and adults. ...


See also

This article or section does not cite its references or sources. ... Views of a Foetus in the Womb, Leonardo da Vinci, ca. ... Auxology is a meta-term covering the study of all aspects of human physical growth; though it is also a fundamental of biology generally. ... Embryogenesis is the process by which the embryo is formed and develops. ... Mammalian embryogenesis is the process of cell division and cellular differentiation which leads to the development of a mammalian embryo. ... Life-history theory explores how an organism makes a living by integrating ontogeny an phylogeny. ...

Footnotes

  1. ^ Approximately
The placenta (Latin for cake, referencing its appearance in humans) is an ephemeral organ present in placental vertebrates, such as eutherial mammals and sharks during gestation (pregnancy). ... Decidua is the term for the uterine lining (endometrium) during a pregnancy. ... Before the fertilized ovum reaches the uterus, the mucous membrane of the body of the uterus undergoes important changes and is then known as the decidua. ... Chorionic villi are villi that sprout from the chorion, in order to give a maximum area of contact with the maternal blood. ... The trophoblast proliferates rapidly and forms a network of branching processes which cover the entire ovum and invade and destroy the maternal tissues and open into the maternal bloodvessels, with the result that the spaces in the trophoblastic network are filled with maternal blood; these spaces communicate freely with one... The gestational sac is the only available intrauterine structure that can be used to determine if an intrauterine pregnancy (IUP) exists, until the embryo is identified. ... For the alien race in Stephen Donaldsons The Gap Cycle, see Amnion (Gap Cycle). ... A drawing of the amniotic sac from Grays Anatomy. ... amniotic sac The amniotic sac is a tough but thin transparent pair of membranes, which hold a developing embryo (and later fetus) until shortly before birth. ... For the entertainment company see Chorion (company) The chorion surrounds the embryo and other membranes. ... An Introduction to Histogenesis Histogenesis is defined as the formation of tissues and organs from undifferentiated cells (Encarta Dictionary). ... Programmed cell death (PCD) is the deliberate suicide of an unwanted cell in a multicellular organism. ... Mouse embryonic stem cells. ... The cells that give rise to the gametes are often set aside during cleavage. ... Organogenesis is a stage of animal development where the ectoderm, endoderm, and mesoderm are formed. ... The vertebrate limb arises out of a general morphogenetic area called a limb field. ... In embryology, the limb bud is a structure formed by the developing limb, derived from lateral plate mesoderm[citation needed]. It is intimately related with the apical ectodermal ridge, which secretes factors inducing the initial differentiation of the limb bud. ... The Apical Ectodermal Ridge (AER) is a critical component in vertebrate limb development. ... Transverse section showing the lens and the optic cup. ... Cutaneous structures arise from the epidermis and include a variety of features such as hair, feathers, claws and nails. ... The heart is the first functional organ in a vertebrate embryo. ... In prenatal development, the urinary and reproductive organs are developed from the intermediate mesoderm. ...

 
 

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