Embryonic Stage (Weeks 5 to 9) Fetal Stage (Weeks 10+) Fetal development is the term used when talking about the procession of events that starts when sperm and egg meet and unfolds in an orderly progression to form a baby. For something that "simply happens" once a woman gets pregnant, it is amazingly complex—and a lot of fun to think about.The fetal stage lasts a total of approximately 30 weeks. Figure \(\PageIndex{2}\) shows a seven-week-old embryo that is just getting ready to begin the fetal stage of development. At 7 weeks the embryo is about 10 mm long and has a big forehead. It is developing the inner ear but not the outer ear. The limb buds are visible.Early Embryologic Development. The development of the eye begins with a process called gastrulation. This critical event transforms the blastula into a gastrula, which is a three-layered structure comprised of the endoderm, mesoderm, and ectoderm layers. These three germ layers give rise to all the major tissues and organs in the body ...2 days ago · and has not yet reached 8 weeks of development since the first mitotic division." This definition was also published later by the same group in 2007. Historical Definition "The distinction between the embryonic and the fetal periods at 8 postovulatory weeks has proved valuable. It is based primarily on the probability that more than 90 percent ... In addition, fetal brains were obtained after spontaneous abortions, under the same ethical guidelines. We examined 10 embryonic and early fetal human brains. The embryonic material, 5–7 gestational weeks (GW) old, was classified on the basis of external morphology and brain features, according to the Carnegie stages (O'Rahilly and Müller ...2) EMBRYONIC PERIOD - extends from week 3 through 8 of gestation; conceptus grows, folds, and forms rudimentary organ systems; called an embryo. 3) FETAL PERIOD - lasts from week 9 through 38 of gestation, or until birth; conceptus is now called a fetus; it grows larger and continues to develop until its organ systems can function without ...The placenta is a vital organ with multiple functions, such as endocrine, immune, and physiological. The placenta is formed gradually during the first three months of pregnancy, while, after the fourth month, it grows parallel to the development of the uterus. Once completed, it resembles a spongy disc 20 cm in diameter and 3 cm thick. It is a temporary organ, whose genetic characteristics are ...MeSH Unique ID: D005314. Entry Terms: Embryo and Fetal Development. Prenatal Programming. Programming, Prenatal. Previous Indexing: Fetus/physiology (1966-1984) Growth (1966-1984) Early Embryologic Development. The development of the eye begins with a process called gastrulation. This critical event transforms the blastula into a gastrula, which is a three-layered structure comprised of the endoderm, mesoderm, and ectoderm layers. These three germ layers give rise to all the major tissues and organs in the body ...The Fetal Period (Weeks 9-40) The fetal period is the final stage of prenatal development and occurs from the ninth week until birth. During this stage, the developing organism is called a fetus and undergoes a period of maturation, where the organs and body systems continue to develop and mature. During the fetal period, the fetus gains weight ...Research on the teratogenic effects of cocaine began in the early 1980s, and in 1985 research on the effects of cocaine on prenatal development gained widespread attention. Since then, numerous studies have contributed to information about the detrimental impacts of maternal cocaine use on embryonic and fetal development.By the end of the embryonic stage, most organs have started to form, although they will continue to develop and grow in the next stage (that of the fetus). As the embryo undergoes all of these changes, its cells continuously undergo mitosis, allowing the embryo to grow in size, as well as complexity. Figure 23.3. 3: Blastula and Gastrula.Jun 14, 2021 · Embryonic Stage (Weeks 5 to 9) Fetal Stage (Weeks 10+) Fetal development is the term used when talking about the procession of events that starts when sperm and egg meet and unfolds in an orderly progression to form a baby. For something that "simply happens" once a woman gets pregnant, it is amazingly complex—and a lot of fun to think about. The brain develops over the course of the prenatal period, but it will continue to go through more changes during the early years of childhood. There are three stages of prenatal development: the germinal, embryonic, and fetal stages. The first two weeks after conception are known as the germinal stage, the third through the eighth week is ...Development at 8 Weeks. 4 /13. The embryo is now a little over half an inch in size. Eyelids and ears are forming, and you can see the tip of the nose. The arms and legs are well formed. The ...Research on the teratogenic effects of cocaine began in the early 1980s, and in 1985 research on the effects of cocaine on prenatal development gained widespread attention. Since then, numerous studies have contributed to information about the detrimental impacts of maternal cocaine use on embryonic and fetal development.Jun 3, 2022 · Fetal development continues during the third trimester. Your baby will open his or her eyes, gain more weight, and prepare for delivery. By Mayo Clinic Staff. The end of your pregnancy is near! By now, you're eager to meet your baby face to face. Your uterus, however, is still a busy place. Here's a weekly calendar of events for fetal ... Jan 22, 2014 · Teratogens may affect the embryo or fetus in a number of ways, causing physical malformations, problems in the behavioral or emotional development of the child, and decreased intellectual quotient (IQ) in the child. Additionally, teratogens may also affect pregnancies and cause complications such as preterm labors, spontaneous abortions, or ... Heat stress can disrupt early embryonic development. Effects of heat stress on embryonic survival decrease as embryos advance in development. Heat stress at day 1 or days 1–3 after breeding decreases embryonic survival. In contrast, superovulated cows appear to be more resistant to heat stress in terms of early pregnancy.Heat stress can disrupt early embryonic development. Effects of heat stress on embryonic survival decrease as embryos advance in development. Heat stress at day 1 or days 1–3 after breeding decreases embryonic survival. In contrast, superovulated cows appear to be more resistant to heat stress in terms of early pregnancy.The placenta is a vital organ with multiple functions, such as endocrine, immune, and physiological. The placenta is formed gradually during the first three months of pregnancy, while, after the fourth month, it grows parallel to the development of the uterus. Once completed, it resembles a spongy disc 20 cm in diameter and 3 cm thick. It is a temporary organ, whose genetic characteristics are ...1972. Part of Photograph collection on The Mount Sinai Hospital and Icahn School of Medicine at Mount Sinai. Included caption reads: "Looking into how genes are activated at precise times and in specific tissues of the developing fetus is what Dr. Moyra Smith's work involves. This is among the most important and least understood aspects of ... During fetal development, hematopoiesis occurs in multiple waves throughout the developing embryo and fetus, including extraembryonic yolk sac (YS), the para-aortic region of the embryo, fetal liver, and placenta before eventually homing to the bone marrow where it occurs just before birth.end of the 2nd week through the 8th week. all vital organs are forming. exposure to teratogens could be fatal. What is the fetal stage of fetal development? end of the 8th week through birth. all major organs are formed so defects are more minor. refinement and development occurs during this stage.Ovulation rate and embryo number were recorded for all animals. With the exception of the G/P1 animals, embryonic and placental weight were recorded for four conceptuses per sow on day 20-30; on day 85-90 two conceptuses per sow were dissected to determine placental and fetal development. Fetal DevelopmentDefinitionThe progressive growth that occurs between fertilization of an egg to the birth of a baby.DescriptionPre-embryonic stageThe pre-embryonic stage begins with fertilization and extends through the first two weeks of pregnancy.Your baby moves through different stages, starting as a blastocyst, then maturing into an embryo, and then a fetus. Around the 5 week mark, cells in your baby's future heart will begin to flicker. At 27 weeks they'll have regular sleep and wake cycles, and at 39 weeks your baby is physically developed.Study with Quizlet and memorize flashcards containing terms like A woman says, "My husband and I will be trying to have a baby soon." Which statement by the woman demonstrates an understanding of the growth that occurs during the embryonic period?, A woman at 8½ weeks' gestation presents for a prenatal check-up. She is eager to find out the baby's sex. Which response by the nurse best ...Jun 14, 2021 · Embryonic Stage (Weeks 5 to 9) Fetal Stage (Weeks 10+) Fetal development is the term used when talking about the procession of events that starts when sperm and egg meet and unfolds in an orderly progression to form a baby. For something that "simply happens" once a woman gets pregnant, it is amazingly complex—and a lot of fun to think about. Mar 31, 2017 · Pregnancy jargon explained. The difference between an embryo and a fetus has to do with the different phases of baby’s development. “The embryo is defined as the developing pregnancy from the time of fertilization until the end of the eighth week of gestation, when it becomes known as a fetus,” says James A. O’Brien, MD, medical ... Fetal development continues during the third trimester. Your baby will open his or her eyes, gain more weight, and prepare for delivery. By Mayo Clinic Staff. The end of your pregnancy is near! By now, you're eager to meet your baby face to face. Your uterus, however, is still a busy place. Here's a weekly calendar of events for fetal ...Much progress has been made over the past decades in the development of in vitro techniques for the assessment of chemically induced effects in embryonic and fetal development. In vitro assays have originally been developed to provide information on the mechanism of action of normal development, and have hence more adequately been used in ... Your baby moves through different stages, starting as a blastocyst, then maturing into an embryo, and then a fetus. Around the 5 week mark, cells in your baby's future heart will begin to flicker. At 27 weeks they'll have regular sleep and wake cycles, and at 39 weeks your baby is physically developed.The pre-axial border medially moves between the fetal and early postnatal periods, and the foot sole can be placed on the ground. Nonetheless, the precise timeline when this posture is achieved remains poorly understood. The hip joint is the most freely movable joint in the lower limbs and largely determines the lower-limb posture. The present study aimed to establish a timeline of lower-limb ...Much progress has been made over the past decades in the development of in vitro techniques for the assessment of chemically induced effects in embryonic and fetal development. In vitro assays have originally been developed to provide information on the mechanism of action of normal development, and have hence more adequately been used in ... Early Embryologic Development. The development of the eye begins with a process called gastrulation. This critical event transforms the blastula into a gastrula, which is a three-layered structure comprised of the endoderm, mesoderm, and ectoderm layers. These three germ layers give rise to all the major tissues and organs in the body ...By the end of the embryonic stage, most organs have started to form, although they will continue to develop and grow in the next stage (that of the fetus). As the embryo undergoes all of these changes, its cells continuously undergo mitosis, allowing the embryo to grow in size, as well as complexity. Figure 23.3. 3: Blastula and Gastrula.This prevents free communication between the ventricular system and the amniotic cavity. The second milestone is development of the meninges, which separate the central nervous system from the rest of the body. The embryonic origin of the meninges varies across species.Week 1 to Week 8 (GA 10)are considered the embryonic period of development. Week 9 to week 37 (GA 11-39) or birth are considered the fetal period of development. First month (4 weeks) after birth is the neonatal period of development. Toxic metals reaching the fetus could impair or alter the uterine environment and dysregulate the fetal epigenome, given that the embryo and fetus are highly susceptible to epigenetic dysregulation by environmental pollutants, 115,119 may affect gene expression and enzyme activity in placental trophoblast cells, 124 act as endocrine disruptors ... 71. Fertilization and Development. In approximately nine months, a single cell—a fertilized egg—develops into a fully formed infant consisting of trillions of cells with myriad specialized functions. The dramatic changes of fertilization, embryonic development, and fetal development are followed by remarkable adaptations of the newborn to ... MeSH Unique ID: D005314. Entry Terms: Embryo and Fetal Development. Prenatal Programming. Programming, Prenatal. Previous Indexing: Fetus/physiology (1966-1984) Growth (1966-1984) Prenatal development (from Latin natalis 'relating to birth') includes the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic development, and continues in fetal development until birth . In human pregnancy, prenatal development is ...The brain develops over the course of the prenatal period, but it will continue to go through more changes during the early years of childhood. There are three stages of prenatal development: the germinal, embryonic, and fetal stages. The first two weeks after conception are known as the germinal stage, the third through the eighth week is ...Mar 1, 2013 · Early in gestation, during the embryonic stage, drugs can have significant teratogenic effects. However, during the fetal period, after major structural development is complete, drugs have more subtle effects, including abnormal growth and/or maturation, alterations in neurotransmitters and their receptors, and brain organization. There are three stages of fetal development: germinal, embryonic and fetal. Most people don’t talk about their pregnancy in these terms, but it can be helpful to know. Germinal stage. The germinal stage is the shortest stage of fetal development. It begins at conception when a sperm and egg join in your fallopian tube. The sperm fertilizes ...Study with Quizlet and memorize flashcards containing terms like Developmental psychologists study physical, cognitive, and ________ changes throughout the human life span. A) zygotic B) embryonic C) genetic D) social, Dr. Birkin's major research interest is the development of motor skills in children. It is most likely that Dr. Birkin is a ________ psychologist. cognitive developmental ... The Fetal Period (Weeks 9-40) The fetal period is the final stage of prenatal development and occurs from the ninth week until birth. During this stage, the developing organism is called a fetus and undergoes a period of maturation, where the organs and body systems continue to develop and mature. During the fetal period, the fetus gains weight ...During embryonic and fetal development much of the skeleton initiates as a cartilaginous scaffold, which is progressively resorbed and replaced by bone. Endochondral bone formation continues until the growth plates fuse during puberty. At all life stages adequate delivery of mineral is required for …Development at 8 Weeks. 4 /13. The embryo is now a little over half an inch in size. Eyelids and ears are forming, and you can see the tip of the nose. The arms and legs are well formed. The ...Jun 3, 2022 · Fetal development continues during the third trimester. Your baby will open his or her eyes, gain more weight, and prepare for delivery. By Mayo Clinic Staff. The end of your pregnancy is near! By now, you're eager to meet your baby face to face. Your uterus, however, is still a busy place. Here's a weekly calendar of events for fetal ... Fetal Development: 2nd Month Second month • Great changes in morphology occur • Limbs assume adult shape • Major internal organs are evident • Embryo reaches about 25 mm. Fetal Development: 3rd Month Third month • Development is essentially complete except for lungs and brain • Developing human is now called a fetus • It carries ...Jul 22, 2023 · a. "The heart chambers are formed in week 5." b. "Cardiac development occurs the most rapidly during weeks 7 and 8." c. "The cardiac system develops faster than the central nervous system." d. "The heart is beating, but the heart chambers don't form during the embryonic period." a. Definition of embryology and fetal development 15 Introduction 15 Embryonic period 16 Teratogens 17 Development of the foot 18 Fetal period 21 Term versus pre-term gestation 23 Low birth weight risks 24 Apgar scores 25 Growth 27 Foot growth 27 The foot and lower limb at birth 28 Summary 29 Definition of embryology and fetal development The period of in utero development from conception to the ...Toxic metals reaching the fetus could impair or alter the uterine environment and dysregulate the fetal epigenome, given that the embryo and fetus are highly susceptible to epigenetic dysregulation by environmental pollutants, 115,119 may affect gene expression and enzyme activity in placental trophoblast cells, 124 act as endocrine disruptors ...Feb 12, 2023 · Embryogenesis is a complex process and is divided between pre-implantation, embryo, and fetal period. This process is highly susceptible to various external factors such as teratogenic drugs, alcohol, smoking, radiation, and even the lack of appropriate nutrition. Ionizing radiation way more than non-ionizing has known effects in developing fetus with fatal outcomes. Implantation begins the first week and the embryo continues to grow. The embryo is about 1 / 100 of an inch long at this time. WEEK 4 (6 weeks after the first day of the last normal menstrual period) The embryo is about 1 / 6-inch long and has developed a head and a trunk. Structures that will become arms and legs, called limb buds, begin to ... Embryonic/fetal development proceeds from rostral (nose and mouth area) to caudal (posterior). The skull and vertebral column are produced by intramembranous ossification. As development proceeds down the body axis, the long bones of the arms and legs are produced by endochondral ossification. Intramembranous ossification is one of the two ...Embryonic development encompasses the period of time at which three germ layers differentiate: ectoderm, mesoderm, and endoderm. Organ systems are formed from these germ layers, with most of the reproductive tract being derived from mesoderm. Organogenesis is complete prior to the fetal stage in canine embryos, but sexual differentiation occurs ...Of those causes, failure of development of conceptuses (embryo and extra-embryonic membranes) during the peri-implantation period is primarily responsible for embryonic losses before day 30 of gestation and inadequate uterine capacity is the major reason for fetal deaths and suboptimal growth after day 30 (Bazer et al. 2009a, b).The placenta is a vital organ with multiple functions, such as endocrine, immune, and physiological. The placenta is formed gradually during the first three months of pregnancy, while, after the fourth month, it grows parallel to the development of the uterus. Once completed, it resembles a spongy disc 20 cm in diameter and 3 cm thick. It is a temporary organ, whose genetic characteristics are ...2) EMBRYONIC PERIOD - extends from week 3 through 8 of gestation; conceptus grows, folds, and forms rudimentary organ systems; called an embryo. 3) FETAL PERIOD - lasts from week 9 through 38 of gestation, or until birth; conceptus is now called a fetus; it grows larger and continues to develop until its organ systems can function without ...The placenta is the largest fetal organ, and toward the end of pregnancy the umbilical circulation receives at least 40% of the biventricular cardiac output. It is not surprising, therefore, that there are likely to be close haemodynamic links between the development of the placenta and the fetal heart. Development of the placenta is precocious, and in advance of that of the fetus. The ... In addition, fetal brains were obtained after spontaneous abortions, under the same ethical guidelines. We examined 10 embryonic and early fetal human brains. The embryonic material, 5–7 gestational weeks (GW) old, was classified on the basis of external morphology and brain features, according to the Carnegie stages (O'Rahilly and Müller ...Jun 18, 2014 · Most drugs of abuse easily cross the placenta and can affect fetal brain development. In utero exposures to drugs thus can have long-lasting implications for brain structure and function. These ... The chart in this fact sheet shows the critical periods of development for different parts of the body. The chart starts from the time of conception when the egg and sperm join. The weeks listed on the chart are the “embryonic age” or “fetal age” of a pregnancy. This is different from a common way of dating a pregnancy called ...Dec 18, 2014 · Fetal development. Prenatal or antenatal development is the process in which embryo or fetus gestates during pregnancy from fertilization until birth. It is also known as fetal development or embryology. Development biology is the study of the sequences of events from the fertilization of a secondary oocyte by a sperm cell to the formation of ... 2 days ago · and has not yet reached 8 weeks of development since the first mitotic division." This definition was also published later by the same group in 2007. Historical Definition "The distinction between the embryonic and the fetal periods at 8 postovulatory weeks has proved valuable. It is based primarily on the probability that more than 90 percent ... Development begins at the moment of conception, when the sperm from the father merges with the egg from the mother. Within a span of 9 months, development progresses from a single cell into a zygote and then into an embryo and fetus. The fetus is connected to the mother through the umbilical cord and the placenta, which allow the fetus and ... By the end of the embryonic stage, most organs have started to form, although they will continue to develop and grow in the next stage (that of the fetus). As the embryo undergoes all of these changes, its cells continuously undergo mitosis, allowing the embryo to grow in size, as well as complexity. Figure 23.3. 3: Blastula and Gastrula.Much progress has been made over the past decades in the development of in vitro techniques for the assessment of chemically induced effects in embryonic and fetal development. In vitro assays have originally been developed to provide information on the mechanism of action of normal development, and have hence more adequately been used in ... end of the 2nd week through the 8th week. all vital organs are forming. exposure to teratogens could be fatal. What is the fetal stage of fetal development? end of the 8th week through birth. all major organs are formed so defects are more minor. refinement and development occurs during this stage. By the end of the embryonic stage, most organs have started to form, although they will continue to develop and grow in the next stage (that of the fetus). As the embryo undergoes all of these changes, its cells continuously undergo mitosis, allowing the embryo to grow in size, as well as complexity. Figure 23.3. 3: Blastula and Gastrula.Mar 31, 2017 · Pregnancy jargon explained. The difference between an embryo and a fetus has to do with the different phases of baby’s development. “The embryo is defined as the developing pregnancy from the time of fertilization until the end of the eighth week of gestation, when it becomes known as a fetus,” says James A. O’Brien, MD, medical ... MeSH Unique ID: D005314. Entry Terms: Embryo and Fetal Development. Prenatal Programming. Programming, Prenatal. Previous Indexing: Fetus/physiology (1966-1984) Growth (1966-1984)Jun 3, 2022 · Eight weeks into your pregnancy, or six weeks after conception, your baby's lower limb buds take on the shape of paddles. Fingers have begun to form. Small swellings outlining the future shell-shaped parts of your baby's ears develop and the eyes become obvious. The upper lip and nose have formed. The Fetal Period (Weeks 9-40) The fetal period is the final stage of prenatal development and occurs from the ninth week until birth. During this stage, the developing organism is called a fetus and undergoes a period of maturation, where the organs and body systems continue to develop and mature. During the fetal period, the fetus gains weight ...During fetal development, hematopoiesis occurs in multiple waves throughout the developing embryo and fetus, including extraembryonic yolk sac (YS), the para-aortic region of the embryo, fetal liver, and placenta before eventually homing to the bone marrow where it occurs just before birth.Toxic metals reaching the fetus could impair or alter the uterine environment and dysregulate the fetal epigenome, given that the embryo and fetus are highly susceptible to epigenetic dysregulation by environmental pollutants, 115,119 may affect gene expression and enzyme activity in placental trophoblast cells, 124 act as endocrine disruptors ...The brain develops over the course of the prenatal period, but it will continue to go through more changes during the early years of childhood. There are three stages of prenatal development: the germinal, embryonic, and fetal stages. The first two weeks after conception are known as the germinal stage, the third through the eighth week is ...The three stages of prenatal development include the germinal stage, the embryonic stage, and the fetal stage. This period of time begins with fertilization which is when a sperm meets an ovum, or ...Study with Quizlet and memorize flashcards containing terms like Which health problem may be identified by a TORCH screening test?, The most critical time for teratogenic influence in embryonic development is:, A pregnant client has just undergone cytogenetic studies to determine fetal karyotyping. She learns that her fetus has trisomy 21.An embryo at the end of 7 weeks of development is only 10 mm in length, but its developing eyes, limb buds, and tail are already visible. (This embryo was derived from an ectopic pregnancy.) (credit: Ed Uthman) During the sixth week, uncontrolled fetal limb movements begin to occur.Canine embryonic and fetal development: a review. 2008 Aug;70 (3):300-3. doi: 10.1016/j.theriogenology.2008.04.029. Epub 2008 May 29. The progression from a fertilized oocyte to a newborn puppy is a remarkable phenomenon that occurs in a period of approximately two months. Embryonic development encompasses the period of time at which three germ ...An embryo is the early stage of a baby’s development during pregnancy. The first stage is the fertilized egg ( zygote ). It divides to become a blastocyst and travels down the fallopian tube to the uterus, where it may implant to establish the pregnancy. The developing baby is termed an embryo from week five until the end of the 10th week of ...Mar 30, 2023 · Early Embryologic Development. The development of the eye begins with a process called gastrulation. This critical event transforms the blastula into a gastrula, which is a three-layered structure comprised of the endoderm, mesoderm, and ectoderm layers. These three germ layers give rise to all the major tissues and organs in the body ...
A) person-to-person differences within cultural groups are larger than differences between. cultural groups. 6. One of the three major concerns of developmental psychology involves a focus on. A) conception and prenatal development. B) continuity and stages. C) embryonic and fetal development.. 170512
Embryonic/fetal development proceeds from rostral (nose and mouth area) to caudal (posterior). The skull and vertebral column are produced by intramembranous ossification. As development proceeds down the body axis, the long bones of the arms and legs are produced by endochondral ossification. Intramembranous ossification is one of the two ...Your baby moves through different stages, starting as a blastocyst, then maturing into an embryo, and then a fetus. Around the 5 week mark, cells in your baby's future heart will begin to flicker. At 27 weeks they'll have regular sleep and wake cycles, and at 39 weeks your baby is physically developed.By the end of the embryonic stage, most organs have started to form, although they will continue to develop and grow in the next stage (that of the fetus). As the embryo undergoes all of these changes, its cells continuously undergo mitosis, allowing the embryo to grow in size, as well as complexity. Figure 23.3. 3: Blastula and Gastrula.The three stages of prenatal development include the germinal stage, the embryonic stage, and the fetal stage. This period of time begins with fertilization which is when a sperm meets an ovum, or ...Fetal Development: 2nd Month Second month • Great changes in morphology occur • Limbs assume adult shape • Major internal organs are evident • Embryo reaches about 25 mm. Fetal Development: 3rd Month Third month • Development is essentially complete except for lungs and brain • Developing human is now called a fetus • It carries ...The fetal stage lasts a total of approximately 30 weeks. Figure \(\PageIndex{2}\) shows a seven-week-old embryo that is just getting ready to begin the fetal stage of development. At 7 weeks the embryo is about 10 mm long and has a big forehead. It is developing the inner ear but not the outer ear. The limb buds are visible. Grass-fed animal fats supply vitamins E and K 2; palm oil, fresh fruits and vegetables, nuts, and freshly ground grains are also sources of vitamin E; fermented foods are also sources of vitamin K 2. Leafy greens supply vitamin K 1. Biotin can be obtained from liver and egg yolks.Teratogens may affect the embryo or fetus in a number of ways, causing physical malformations, problems in the behavioral or emotional development of the child, and decreased intellectual quotient (IQ) in the child. Additionally, teratogens may also affect pregnancies and cause complications such as preterm labors, spontaneous abortions, or ...An embryo is the early stage of a baby’s development during pregnancy. The first stage is the fertilized egg ( zygote ). It divides to become a blastocyst and travels down the fallopian tube to the uterus, where it may implant to establish the pregnancy. The developing baby is termed an embryo from week five until the end of the 10th week of ...At 22 days after conception, the neural tube forms along the back of the embryo, developing into the spinal cord and brain. Growth during prenatal development occurs in two major directions: from head to tail (cephalocaudal development) and from the midline outward (proximodistal development). The embryonic stage of gestation is the period after implantation, during which all major organs and structures within the growing mammal are formed. Once the embryo is fully formed, it expands, grows and continues to develop into what is known as the stage of fetal development. This is when the mother becomes physically and visibly pregnant. Much progress has been made over the past decades in the development of in vitro techniques for the assessment of chemically induced effects in embryonic and fetal development. In vitro assays have originally been developed to provide information on the mechanism of action of normal development, and have hence more adequately been used in ...The Fetal Period (Weeks 9-40) The fetal period is the final stage of prenatal development and occurs from the ninth week until birth. During this stage, the developing organism is called a fetus and undergoes a period of maturation, where the organs and body systems continue to develop and mature. During the fetal period, the fetus gains weight ... Keep in mind that this is different than the three trimesters of pregnancy. Prenatal Development. Let’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. The Germinal Period (Weeks 1-2) Figure 2. Sperm and Ovum at Conception There are three stages of fetal development: germinal, embryonic and fetal. Most people don’t talk about their pregnancy in these terms, but it can be helpful to know. Germinal stage. The germinal stage is the shortest stage of fetal development. It begins at conception when a sperm and egg join in your fallopian tube. The sperm fertilizes ...Radiation effects on embryonic and fetal development are generally considered low risk compared to the normal risks of pregnancy. Most diagnostic x-ray and nuclear medicine examinations are <50 mSv and have not been demonstrated to produce any significant impact on fetal growth and development. For doses up to 100 mSv, any radiation risks are ...A) person-to-person differences within cultural groups are larger than differences between. cultural groups. 6. One of the three major concerns of developmental psychology involves a focus on. A) conception and prenatal development. B) continuity and stages. C) embryonic and fetal development..