The process of prenatal development occurs in three main stages. The first two weeks after conception are known as the germinal stage, the third through the eighth week is known as the embryonic period, and the time from the ninth week until birth is known as the fetal period.
What is the most critical stage of fetal development?
The embryonic period is the most critical period of development because of the formation of internal and external structures.
What is a critical period of pregnancy?
First Trimester (0 to 13 Weeks)
The first trimester is the most crucial to your baby’s development. During this period, your baby’s body structure and organ systems develop. Most miscarriages and birth defects occur during this period.
What are the stages of embryo development?
This union marks the beginning of the prenatal period, which in humans encompasses three distinct stages: (1) the pre-embryonic stage, the first two weeks of development, which is a period of cell division and initial differentiation (cell maturation), (2) the embryonic period , or period of organogenesis, which lasts ...
Which is likely to be the most critical period of fetal development and why?
The developing child is most at risk for some of the most severe problems during the first three months of development . Unfortunately, this is a time at which most mothers are unaware that they are pregnant. It is estimated that 10% of all birth defects are caused by a prenatal exposure or teratogen.
What happens during birth that is so critical to development?
Before the baby is born, blood goes through the placenta to get rid of waste and to pick up oxygen and nutrients that come from the mother. The developing baby manages on relatively low oxygen levels while in the uterus. After birth the child is exposed to suddenly higher (potentially dangerous) oxygen levels.
What is the difference between and embryo and a fetus?
An embryo is the early stage of human development in which organs are critical body structures are formed. An embryo is termed a fetus beginning in the 11th week of pregnancy, which is the 9th week of development after fertilization of the egg. A zygote is a single-celled organism resulting from a fertilized egg.
What are the critical periods in the development process of an embryo and fetus when do they occur and how might they be disrupted?
In general, major defects of the body and internal organs are more likely to occur between 3 to 12 embryo / fetal weeks . This is the same as 5 to 14 gestational weeks (weeks since the first day of your last period). This is also referred to as the first trimester.
What is it meant by the term critical period?
1. an early stage in life when an organism is especially open to specific learning, emotional, or socializing experiences that occur as part of normal development and will not recur at a later stage.
Why is the embryonic stage critical?
The embryonic stage is a critical period of development. Genetic defects or harmful environmental exposures (such as alcohol or radiation) during this stage are likely to have devastating effects . Several extraembryonic structures form at the same time as the embryo, helping the embryo to grow and develop.
What is the fetal development?
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.
What is the most notable event during the fetal period quizlet?
What is the most notable event during the fetal period? The development of the germ layers .
Why is the period of the embryo regarded as the most dramatic prenatal period?
This is the most important time of prenatal development because the embryo is developing the foundations for a healthy baby . The blastocyst that implanted in the uterus continues to divide rapidly after implantation. Through a process called differentiation, cells begin to take on different functions.
When does an embryo become a fetus?
Within 24 hours after fertilization, the egg that will become your baby rapidly divides into many cells. By the eighth week of pregnancy , the embryo develops into a fetus. There are about 40 weeks to a typical pregnancy.
What is the most critical physiologic change required of the newborn after birth?
Establishing respirations is critical to the newborn’s transition, as lungs become the organ of gas exchange after separation from maternal uteroplacental circulation. Over 90% of newborns make the transition from intrauterine life to extrauterine life without difficulty, requiring little to no assistance (NRP, 2010).
Can you hear a baby cry in the womb?
While it’s true your baby can cry in the womb, it doesn’t make a sound , and it’s not something to worry about. The baby’s practice cries include imitating the breathing pattern, facial expression, and mouth movements of a baby crying outside of the womb. You shouldn’t worry that your baby is in pain.
What happens during the embryonic period?
The embryonic stage plays an important role in the development of the brain . Approximately four weeks after conception, the neural tube forms. This tube will later develop into the central nervous system including the spinal cord and brain. The neural tube begins to form along with an area known as the neural plate.
Which period of prenatal development is considered the critical period quizlet?
a. The term critical period means the first 12 weeks of a pregnancy. The embryonic period is also considered to be the critical period of development because during this period all the baby’s organs begin to develop and function at a basic level.
What’s the difference between blastocyst and embryo?
After the implantation of it in the uterine wall, the blastocyst is referred to as the embryo. ... The main difference between blastocyst and embryo is that blastocyst is a thin-walled hollow structure from which the embryo arises whereas embryo is the early stages of the placental development from which the fetus arises .
What is the difference between an embryo and a fetus quizlet?
The term embryo is used to describe the developing individual during the first trimester. The term fetus is used to describe the developing individual from week 8 to week 39.
Why was it called the critical period?
During what historians often call the “critical period” after the American Revolution, many were concerned that the Articles of Confederation were inadequate for the states to grow commercially and economically . Later, Henry would become a leading opponent of the Constitution. ...
What are critical and sensitive periods of development?
Sensitive periods generally refer to a limited time window in development during which the effects of experience on the brain are unusually strong, whereas a critical period is defined as a special class of sensitive periods where behaviors and their neural substrates do not develop normally if appropriate stimulation ...
What is a critical period of development quizlet?
What is a critical period? A critical period is a specific period in development during which an organism is most vulnerable to the deprivation or absence of certain environmental stimuli or experiences .
What major events occur during the embryonic period?
The embryonic stage of pregnancy is a stage that spans from implantation through organogenesis. Three major events occur during the embryonic stage: implantation, the division of germ layers, and organogenesis .
Why is prenatal period important?
Pre-Pregnancy and prenatal care can help prevent complications and inform women about important steps they can take to protect their infant and ensure a healthy pregnancy. With regular prenatal care women can: Reduce the risk of pregnancy complications.
What is the main task during the fetal period?
During the fetal stage, the brain develops and the body adds size and weight until the fetus reaches full-term development . This video on prenatal development explains many of the developmental milestones and changes that happen during each month of development for the embryo and fetus.
Which process occurs during the fetal period quizlet?
During the fetal period, the rate of growth slows as the infant prepares for birth . As the time for birth approaches, the fetus’s rate of growth does slow down, but during the entire fetal period, the size of the fetus increases by up to twentyfold.
Is the embryonic period the shortest period of prenatal development?
2: The germinal stage of human development begins with fertilization in a Fallopian tube and ends with implantation in the uterus. The germinal stage of development is the first and shortest of the stages of the human lifespan.
