{"id":159,"date":"2014-09-18T15:39:41","date_gmt":"2014-09-18T15:39:41","guid":{"rendered":"https:\/\/courses.candelalearning.com\/lifespandevelopment1x1\/?post_type=chapter&#038;p=159"},"modified":"2024-04-29T23:14:30","modified_gmt":"2024-04-29T23:14:30","slug":"prenatal-development","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/chapter\/prenatal-development\/","title":{"raw":"Prenatal Development","rendered":"Prenatal Development"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Outcomes<\/h3>\r\n<ul>\r\n \t<li>Differentiate between development during the germinal, embryonic, and fetal periods<\/li>\r\n<\/ul>\r\n<\/div>\r\n<blockquote><span style=\"color: #333333;\">\"The body of the unborn baby is more complex than ours. The preborn baby has several extra parts to his body which he needs only so long as he lives inside his mother. He has his own space capsule, the amniotic sac. He has his own lifeline, the umbilical cord, and he has his own root system, the placenta. These all belong to the baby himself, not to his mother. They are all developed from his original cell.\"[footnote]Day &amp; Liley, The Secret World of a Baby, Random House, 1968, p. 13[\/footnote]\u00a0<\/span><\/blockquote>\r\n<h2>Periods of Prenatal Development<\/h2>\r\nLet's take a look at some of the changes that take place during each of the three periods of prenatal development: the germinal period, the embryonic period, and the fetal period.\r\n<h3>The Germinal Period (Weeks 1-2)<\/h3>\r\n[caption id=\"attachment_580\" align=\"alignleft\" width=\"300\"]<img class=\"wp-image-580 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/1496\/2014\/09\/18153941\/Germinal-300x205.jpeg\" alt=\"magnified photo of sperm approaching ovum.\" width=\"300\" height=\"205\" \/> <strong>Figure 1<\/strong>. Sperm and Ovum at Conception[\/caption]\r\n\r\nConception occurs when a sperm fertilizes an egg and forms a\u00a0<strong>zygote,<\/strong>\u00a0which begins as a one-cell structure. The\u00a0mother and father\u2019s DNA is passed on to the child at the moment of conception. The genetic makeup and sex of the baby are set at this point. The germinal period (about 14 days in length) lasts from conception to implantation of the zygote (fertilized egg) in the lining of the uterus.\r\n\r\nDuring the first week after conception, the zygote divides and multiplies, going from a one-cell structure to two cells, then four cells, then eight cells, and so on. The process of cell division is called <strong>mitosis<\/strong>.\u00a0After the fourth division, differentiation of the cells begins to occur as well. Differentiated cells become more specialized, forming different organs and body parts.\u00a0\u00a0After 5 days of mitosis, there are 100 cells, and after 9 months there are billions of cells.\u00a0Mitosis\u00a0is a fragile process, and fewer than one-half of all zygotes survive beyond the first two weeks (Hall, 2004).\r\n\r\n<span style=\"color: #333333;\">After the zygote divides for about 7\u201310 days and has 150 cells, it travels down the fallopian tubes and implants itself in the lining of the uterus.<\/span>\u00a0It\u2019s estimated that about 60 percent of natural conceptions fail to implant in the uterus. The rate is higher for in vitro conceptions.\u00a0Once the zygote attaches to the uterus, the next stage begins.\r\n<h2>The Embryonic Period (Weeks 3-8)<\/h2>\r\n[caption id=\"attachment_1996\" align=\"alignright\" width=\"200\"]<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/25050356\/548063929_d087ee4a1f_z.jpg\"><img class=\"wp-image-1996 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/25050356\/548063929_d087ee4a1f_z-200x300.jpg\" alt=\"3 to 8 week Human Embryo.\" width=\"200\" height=\"300\" \/><\/a> <strong>Figure 2<\/strong>. Human Embryo[\/caption]\r\n\r\nThe embryonic period begins once the zygote is implanted in the uterine wall. It lasts from the third through the eighth week after conception. <span style=\"color: #333333;\">Upon implantation, this multi-cellular organism is called an\u00a0<strong>embryo<\/strong>. Now blood vessels grow, forming the placenta. The\u00a0<strong>placenta<\/strong>\u00a0is a structure connected to the uterus that provides nourishment and oxygen from the mother to the developing embryo via the umbilical cord. <\/span>\r\n\r\n<span style=\"color: #333333;\">During this period, cells continue to differentiate. Basic structures of the embryo start to develop into areas that will become the head, chest, and abdomen. During the embryonic stage, the heart begins to beat and organs form and begin to function. At 22 days after conception, the neural tube forms along the back of the embryo, developing into the spinal cord and brain.\u00a0<\/span>\r\n\r\nGrowth during prenatal development occurs in two major directions: from head to tail (cephalocaudal\u00a0development) and from the midline outward (proximodistal\u00a0development).\u00a0This means that those structures nearest the head develop before those nearest the feet and those structures nearest the torso develop before those away from the center of the body (such as hands and fingers).\r\n\r\nThe head develops in the fourth week and the precursor to the heart begins to pulse. In the early stages of the embryonic period, gills and a tail are apparent. But by the end of this stage, they disappear and the organism takes on a more human appearance.\u00a0The embryo is approximately 1 inch in length and weighs about 4 grams at the end of this period.\u00a0The embryo can move and respond to touch at this time.\r\n\r\nAbout 20 percent of organisms fail during the embryonic period, usually due to gross chromosomal abnormalities.\u00a0As in the case of the germinal period, often the mother does not yet know that she is pregnant.\u00a0It is during this stage that the major structures of the body are taking form making the embryonic period the time when the organism is most vulnerable to the greatest amount of damage if exposed to harmful substances. Potential mothers are not often aware of the risks they introduce to the developing child during this time.\r\n<h2>The Fetal Period (Weeks 9-40)<\/h2>\r\n[caption id=\"attachment_3498\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/17012732\/797px-Human_fetus_10_weeks_with_amniotic_sac_-_therapeutic_abortion.jpg\"><img class=\"wp-image-3498 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/17012732\/797px-Human_fetus_10_weeks_with_amniotic_sac_-_therapeutic_abortion-300x226.jpg\" alt=\"Fetus at 10 weeks of development.\" width=\"300\" height=\"226\" \/><\/a> <strong>Figure 3<\/strong>. A fetus at 10 weeks of development.[\/caption]\r\n\r\n<span style=\"color: #333333;\">When the organism is about nine weeks old, the embryo is called a <strong>fetus<\/strong>. At this stage, the fetus is about the size of a kidney bean and begins to take on the recognizable form of a human being as the \u201ctail\u201d begins to disappear.<\/span>\r\n\r\n<span style=\"color: #333333;\">From 9\u201312 weeks, the sex organs begin to differentiate. By the 12th week, the fetus has all its body parts including external genitalia. In the following weeks, the fetus will develop hair, nails, teeth and the excretory and digestive systems will continue to develop. At the end of the 12th\u00a0week, the fetus is about 3 inches long and weighs about 28 grams.<\/span>\r\n\r\n<span style=\"color: #333333;\">At about 16 weeks, the fetus is approximately 4.5 inches long. Fingers and toes are fully developed, and fingerprints are visible. During the 4-6th months, the eyes become more sensitive to light and hearing develops. The respiratory system continues to develop. Reflexes such as sucking, swallowing and hiccuping develop during the 5th month. Cycles of sleep and wakefulness are present at that time as well. Throughout the fetal stage, the brain continues to grow and develop, nearly doubling in size from weeks 16 to 28. The majority of the neurons in the brain have developed by 24 weeks although they are still rudimentary and the glial or nerve cells that support neurons continue to grow.\u00a0At 24 weeks the fetus can feel pain (Royal College of Obstetricians and Gynecologists, 1997).<\/span>\r\n\r\n<span style=\"color: #333333;\">The first chance of survival outside the womb, known as the\u00a0age of viability\u00a0is reached at about 22 to 26 weeks (Moore &amp;\u00a0Persaud, 1998). By the time the fetus reaches the sixth month of development (24 weeks), it weighs up to 1.4 pounds. The hearing has developed, so the fetus can respond to sounds. The internal organs, such as the lungs, heart, stomach, and intestines, have formed enough that a fetus born prematurely at this point has a chance to survive outside of the mother\u2019s womb. <\/span>\r\n\r\nBetween the 7th and 9th\u00a0months, the fetus is primarily preparing for birth. It is exercising its muscles, its lungs begin to expand and contract. It is developing fat layers under the skin.\u00a0The fetus gains about 5 pounds and 7 inches during this last trimester of pregnancy which includes a layer of fat gained during the 8th\u00a0month.\u00a0This layer of fat serves as insulation and helps the baby regulate body temperature after birth.\r\n\r\n<span style=\"color: #333333;\">Around 36 weeks, the fetus is almost ready for birth. It weighs about 6 pounds and is about 18.5 inches long, and by week 37 all of the fetus\u2019s organ systems are developed enough that it could survive outside the mother\u2019s uterus without many of the risks associated with premature birth. The fetus continues to gain weight and grow in length until approximately 40 weeks. By then, the fetus has very little room to move around and birth becomes imminent.\u00a0<\/span>\r\n\r\n[caption id=\"attachment_3499\" align=\"aligncenter\" width=\"731\"]<img class=\"wp-image-3499 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/17013105\/CNX_Psych_09_02_Stages.jpg\" alt=\"Images of fetal development from 9 weeks through 40 weeks. At 9 weeks the fetal stage begins. At 12 weeks the sex organs differentiate. At 16 weeks the fingers and toes develop. At 20 weeks hearing begins. At 24 weeks the lungs begin to develop. At 28 weeks the brain grows rapidly. At 32 weeks the bones fully develop. At 36 weeks the muscles fully develop. Full-term development happens at 40 weeks.\" width=\"731\" height=\"763\" \/> <strong>Figure 4<\/strong>. During the fetal stage, the baby\u2019s brain develops and the body adds size and weight until the fetus reaches full-term development.[\/caption]\r\n\r\n<div class=\"textbox examples\">\r\n<h3>Watch It<\/h3>\r\nThis video explains many of the developmental milestones and changes that happen during each month of development for the embryo and fetus.\r\n\r\n[embed]https:\/\/www.youtube.com\/embed\/UA-Tk9qlG9A[\/embed]\r\n\r\nYou can <a href=\"https:\/\/oerfiles.s3-us-west-2.amazonaws.com\/Lifespan+Development\/Transcriptions\/PrenatalDevelopmentWhatWeLearnInsideTheWomb_transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for \"Prenatal Development: What We Learn Inside the Womb\" here (opens in new window)<\/a>.\r\n\r\n<\/div>\r\n<div class=\"textbox tryit\">\r\n<h3>Try It<\/h3>\r\nhttps:\/\/assess.lumenlearning.com\/practice\/e521bf05-122a-48eb-a4ee-50e9bd8adbba\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Glossary<\/h3>\r\n[glossary-page][glossary-term]embryo:[\/glossary-term]\r\n[glossary-definition]a multi-celled organism between two and eight weeks after fertilization[\/glossary-definition]\r\n\r\n[glossary-term]fetus:[\/glossary-term]\r\n[glossary-definition]an unborn human baby from nine weeks after conception until birth[\/glossary-definition]\r\n\r\n[glossary-term]mitosis:[\/glossary-term]\r\n[glossary-definition]the process of cell division[\/glossary-definition]\r\n\r\n[glossary-term]placenta:[\/glossary-term]\r\n[glossary-definition]a structure connected to the uterus that provides nourishment and oxygen from the mother to the developing embryo via the umbilical cord[\/glossary-definition]\r\n\r\n[glossary-term]zygote:[\/glossary-term]\r\n[glossary-definition]a one-cell structure that is created when a sperm and egg merge[\/glossary-definition]\r\n[\/glossary-page]\r\n\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Outcomes<\/h3>\n<ul>\n<li>Differentiate between development during the germinal, embryonic, and fetal periods<\/li>\n<\/ul>\n<\/div>\n<blockquote><p><span style=\"color: #333333;\">&#8220;The body of the unborn baby is more complex than ours. The preborn baby has several extra parts to his body which he needs only so long as he lives inside his mother. He has his own space capsule, the amniotic sac. He has his own lifeline, the umbilical cord, and he has his own root system, the placenta. These all belong to the baby himself, not to his mother. They are all developed from his original cell.&#8221;<a class=\"footnote\" title=\"Day &amp; Liley, The Secret World of a Baby, Random House, 1968, p. 13\" id=\"return-footnote-159-1\" href=\"#footnote-159-1\" aria-label=\"Footnote 1\"><sup class=\"footnote\">[1]<\/sup><\/a>\u00a0<\/span><\/p><\/blockquote>\n<h2>Periods of Prenatal Development<\/h2>\n<p>Let&#8217;s take a look at some of the changes that take place during each of the three periods of prenatal development: the germinal period, the embryonic period, and the fetal period.<\/p>\n<h3>The Germinal Period (Weeks 1-2)<\/h3>\n<div id=\"attachment_580\" style=\"width: 310px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-580\" class=\"wp-image-580 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/1496\/2014\/09\/18153941\/Germinal-300x205.jpeg\" alt=\"magnified photo of sperm approaching ovum.\" width=\"300\" height=\"205\" \/><\/p>\n<p id=\"caption-attachment-580\" class=\"wp-caption-text\"><strong>Figure 1<\/strong>. Sperm and Ovum at Conception<\/p>\n<\/div>\n<p>Conception occurs when a sperm fertilizes an egg and forms a\u00a0<strong>zygote,<\/strong>\u00a0which begins as a one-cell structure. The\u00a0mother and father\u2019s DNA is passed on to the child at the moment of conception. The genetic makeup and sex of the baby are set at this point. The germinal period (about 14 days in length) lasts from conception to implantation of the zygote (fertilized egg) in the lining of the uterus.<\/p>\n<p>During the first week after conception, the zygote divides and multiplies, going from a one-cell structure to two cells, then four cells, then eight cells, and so on. The process of cell division is called <strong>mitosis<\/strong>.\u00a0After the fourth division, differentiation of the cells begins to occur as well. Differentiated cells become more specialized, forming different organs and body parts.\u00a0\u00a0After 5 days of mitosis, there are 100 cells, and after 9 months there are billions of cells.\u00a0Mitosis\u00a0is a fragile process, and fewer than one-half of all zygotes survive beyond the first two weeks (Hall, 2004).<\/p>\n<p><span style=\"color: #333333;\">After the zygote divides for about 7\u201310 days and has 150 cells, it travels down the fallopian tubes and implants itself in the lining of the uterus.<\/span>\u00a0It\u2019s estimated that about 60 percent of natural conceptions fail to implant in the uterus. The rate is higher for in vitro conceptions.\u00a0Once the zygote attaches to the uterus, the next stage begins.<\/p>\n<h2>The Embryonic Period (Weeks 3-8)<\/h2>\n<div id=\"attachment_1996\" style=\"width: 210px\" class=\"wp-caption alignright\"><a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/25050356\/548063929_d087ee4a1f_z.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1996\" class=\"wp-image-1996 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/25050356\/548063929_d087ee4a1f_z-200x300.jpg\" alt=\"3 to 8 week Human Embryo.\" width=\"200\" height=\"300\" \/><\/a><\/p>\n<p id=\"caption-attachment-1996\" class=\"wp-caption-text\"><strong>Figure 2<\/strong>. Human Embryo<\/p>\n<\/div>\n<p>The embryonic period begins once the zygote is implanted in the uterine wall. It lasts from the third through the eighth week after conception. <span style=\"color: #333333;\">Upon implantation, this multi-cellular organism is called an\u00a0<strong>embryo<\/strong>. Now blood vessels grow, forming the placenta. The\u00a0<strong>placenta<\/strong>\u00a0is a structure connected to the uterus that provides nourishment and oxygen from the mother to the developing embryo via the umbilical cord. <\/span><\/p>\n<p><span style=\"color: #333333;\">During this period, cells continue to differentiate. Basic structures of the embryo start to develop into areas that will become the head, chest, and abdomen. During the embryonic stage, the heart begins to beat and organs form and begin to function. At 22 days after conception, the neural tube forms along the back of the embryo, developing into the spinal cord and brain.\u00a0<\/span><\/p>\n<p>Growth during prenatal development occurs in two major directions: from head to tail (cephalocaudal\u00a0development) and from the midline outward (proximodistal\u00a0development).\u00a0This means that those structures nearest the head develop before those nearest the feet and those structures nearest the torso develop before those away from the center of the body (such as hands and fingers).<\/p>\n<p>The head develops in the fourth week and the precursor to the heart begins to pulse. In the early stages of the embryonic period, gills and a tail are apparent. But by the end of this stage, they disappear and the organism takes on a more human appearance.\u00a0The embryo is approximately 1 inch in length and weighs about 4 grams at the end of this period.\u00a0The embryo can move and respond to touch at this time.<\/p>\n<p>About 20 percent of organisms fail during the embryonic period, usually due to gross chromosomal abnormalities.\u00a0As in the case of the germinal period, often the mother does not yet know that she is pregnant.\u00a0It is during this stage that the major structures of the body are taking form making the embryonic period the time when the organism is most vulnerable to the greatest amount of damage if exposed to harmful substances. Potential mothers are not often aware of the risks they introduce to the developing child during this time.<\/p>\n<h2>The Fetal Period (Weeks 9-40)<\/h2>\n<div id=\"attachment_3498\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/17012732\/797px-Human_fetus_10_weeks_with_amniotic_sac_-_therapeutic_abortion.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-3498\" class=\"wp-image-3498 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/17012732\/797px-Human_fetus_10_weeks_with_amniotic_sac_-_therapeutic_abortion-300x226.jpg\" alt=\"Fetus at 10 weeks of development.\" width=\"300\" height=\"226\" \/><\/a><\/p>\n<p id=\"caption-attachment-3498\" class=\"wp-caption-text\"><strong>Figure 3<\/strong>. A fetus at 10 weeks of development.<\/p>\n<\/div>\n<p><span style=\"color: #333333;\">When the organism is about nine weeks old, the embryo is called a <strong>fetus<\/strong>. At this stage, the fetus is about the size of a kidney bean and begins to take on the recognizable form of a human being as the \u201ctail\u201d begins to disappear.<\/span><\/p>\n<p><span style=\"color: #333333;\">From 9\u201312 weeks, the sex organs begin to differentiate. By the 12th week, the fetus has all its body parts including external genitalia. In the following weeks, the fetus will develop hair, nails, teeth and the excretory and digestive systems will continue to develop. At the end of the 12th\u00a0week, the fetus is about 3 inches long and weighs about 28 grams.<\/span><\/p>\n<p><span style=\"color: #333333;\">At about 16 weeks, the fetus is approximately 4.5 inches long. Fingers and toes are fully developed, and fingerprints are visible. During the 4-6th months, the eyes become more sensitive to light and hearing develops. The respiratory system continues to develop. Reflexes such as sucking, swallowing and hiccuping develop during the 5th month. Cycles of sleep and wakefulness are present at that time as well. Throughout the fetal stage, the brain continues to grow and develop, nearly doubling in size from weeks 16 to 28. The majority of the neurons in the brain have developed by 24 weeks although they are still rudimentary and the glial or nerve cells that support neurons continue to grow.\u00a0At 24 weeks the fetus can feel pain (Royal College of Obstetricians and Gynecologists, 1997).<\/span><\/p>\n<p><span style=\"color: #333333;\">The first chance of survival outside the womb, known as the\u00a0age of viability\u00a0is reached at about 22 to 26 weeks (Moore &amp;\u00a0Persaud, 1998). By the time the fetus reaches the sixth month of development (24 weeks), it weighs up to 1.4 pounds. The hearing has developed, so the fetus can respond to sounds. The internal organs, such as the lungs, heart, stomach, and intestines, have formed enough that a fetus born prematurely at this point has a chance to survive outside of the mother\u2019s womb. <\/span><\/p>\n<p>Between the 7th and 9th\u00a0months, the fetus is primarily preparing for birth. It is exercising its muscles, its lungs begin to expand and contract. It is developing fat layers under the skin.\u00a0The fetus gains about 5 pounds and 7 inches during this last trimester of pregnancy which includes a layer of fat gained during the 8th\u00a0month.\u00a0This layer of fat serves as insulation and helps the baby regulate body temperature after birth.<\/p>\n<p><span style=\"color: #333333;\">Around 36 weeks, the fetus is almost ready for birth. It weighs about 6 pounds and is about 18.5 inches long, and by week 37 all of the fetus\u2019s organ systems are developed enough that it could survive outside the mother\u2019s uterus without many of the risks associated with premature birth. The fetus continues to gain weight and grow in length until approximately 40 weeks. By then, the fetus has very little room to move around and birth becomes imminent.\u00a0<\/span><\/p>\n<div id=\"attachment_3499\" style=\"width: 741px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-3499\" class=\"wp-image-3499 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2014\/09\/17013105\/CNX_Psych_09_02_Stages.jpg\" alt=\"Images of fetal development from 9 weeks through 40 weeks. At 9 weeks the fetal stage begins. At 12 weeks the sex organs differentiate. At 16 weeks the fingers and toes develop. At 20 weeks hearing begins. At 24 weeks the lungs begin to develop. At 28 weeks the brain grows rapidly. At 32 weeks the bones fully develop. At 36 weeks the muscles fully develop. Full-term development happens at 40 weeks.\" width=\"731\" height=\"763\" \/><\/p>\n<p id=\"caption-attachment-3499\" class=\"wp-caption-text\"><strong>Figure 4<\/strong>. During the fetal stage, the baby\u2019s brain develops and the body adds size and weight until the fetus reaches full-term development.<\/p>\n<\/div>\n<div class=\"textbox examples\">\n<h3>Watch It<\/h3>\n<p>This video explains many of the developmental milestones and changes that happen during each month of development for the embryo and fetus.<\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-1\" title=\"Prenatal Development: What Babies Learn in the Womb\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/UA-Tk9qlG9A?feature=oembed&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>You can <a href=\"https:\/\/oerfiles.s3-us-west-2.amazonaws.com\/Lifespan+Development\/Transcriptions\/PrenatalDevelopmentWhatWeLearnInsideTheWomb_transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for &#8220;Prenatal Development: What We Learn Inside the Womb&#8221; here (opens in new window)<\/a>.<\/p>\n<\/div>\n<div class=\"textbox tryit\">\n<h3>Try It<\/h3>\n<p>\t<iframe id=\"assessment_practice_e521bf05-122a-48eb-a4ee-50e9bd8adbba\" class=\"resizable\" src=\"https:\/\/assess.lumenlearning.com\/practice\/e521bf05-122a-48eb-a4ee-50e9bd8adbba?iframe_resize_id=assessment_practice_id_e521bf05-122a-48eb-a4ee-50e9bd8adbba\" frameborder=\"0\" style=\"border:none;width:100%;height:100%;min-height:300px;\"><br \/>\n\t<\/iframe><\/p>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>Glossary<\/h3>\n<div class=\"titlepage\">\n<dl>\n<dt>embryo:<\/dt>\n<dd>a multi-celled organism between two and eight weeks after fertilization<\/dd>\n<dt>fetus:<\/dt>\n<dd>an unborn human baby from nine weeks after conception until birth<\/dd>\n<dt>mitosis:<\/dt>\n<dd>the process of cell division<\/dd>\n<dt>placenta:<\/dt>\n<dd>a structure connected to the uterus that provides nourishment and oxygen from the mother to the developing embryo via the umbilical cord<\/dd>\n<dt>zygote:<\/dt>\n<dd>a one-cell structure that is created when a sperm and egg merge<\/dd>\n<\/dl>\n<\/div>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-159\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Original<\/div><ul class=\"citation-list\"><li>Modification, adaptation, and original content. <strong>Authored by<\/strong>: Julie Lazzara for Lumen Learning. <strong>Provided by<\/strong>: Lumen Learning. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Psyc 200 Lifespan Psychology. <strong>Authored by<\/strong>: Laura Overstreet. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/opencourselibrary.org\/econ-201\/\">http:\/\/opencourselibrary.org\/econ-201\/<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><li>Prenatal Development content and fetal stages image. <strong>Provided by<\/strong>: Lumen Learning. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/courses.lumenlearning.com\/waymaker-psychology\/chapter\/stages-of-development\/\">https:\/\/courses.lumenlearning.com\/waymaker-psychology\/chapter\/stages-of-development\/<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><li>Fetus image. <strong>Authored by<\/strong>: Jacopo Werther. <strong>Provided by<\/strong>: Wikimedia. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Human_fetus_10_weeks_with_amniotic_sac_-_therapeutic_abortion.jpg\">https:\/\/commons.wikimedia.org\/wiki\/File:Human_fetus_10_weeks_with_amniotic_sac_-_therapeutic_abortion.jpg<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">All rights reserved content<\/div><ul class=\"citation-list\"><li>Prenatal Development: What Babies Learn Inside the Womb. <strong>Authored by<\/strong>: sprouts. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/www.youtube.com\/watch?time_continue=175&#038;v=UA-Tk9qlG9A\">https:\/\/www.youtube.com\/watch?time_continue=175&#038;v=UA-Tk9qlG9A<\/a>. <strong>License<\/strong>: <em>Other<\/em>. <strong>License Terms<\/strong>: Standard YouTube License<\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section><hr class=\"before-footnotes clear\" \/><div class=\"footnotes\"><ol><li id=\"footnote-159-1\">Day &amp; Liley, The Secret World of a Baby, Random House, 1968, p. 13 <a href=\"#return-footnote-159-1\" class=\"return-footnote\" aria-label=\"Return to footnote 1\">&crarr;<\/a><\/li><\/ol><\/div>","protected":false},"author":74,"menu_order":8,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Psyc 200 Lifespan Psychology\",\"author\":\"Laura Overstreet\",\"organization\":\"\",\"url\":\"http:\/\/opencourselibrary.org\/econ-201\/\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"\"},{\"type\":\"cc\",\"description\":\"Prenatal Development content and fetal stages image\",\"author\":\"\",\"organization\":\"Lumen Learning\",\"url\":\"https:\/\/courses.lumenlearning.com\/waymaker-psychology\/chapter\/stages-of-development\/\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"\"},{\"type\":\"cc\",\"description\":\"Fetus 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