The Period of the Fetus. The final and longest stage of prenatal development, the period of the fetus, extends from the beginning of the ninth week to birth (about seven months). The major organ systems continue to develop in size and function throughout this period and the fetus' size is multiplied by a factor of ten.
How long does it take for prenatal development to take place?
Prenatal development takes about 38 weeks to complete. During this time, a single cell becomes a full-term baby. This time period is divided into different categories of development. The 3 primary stages of prenatal development are the germinal period, the embryonic period, and the fetal period.
What are the stages of prenatal development in human development?
Prenatal development, the process encompassing the period from the formation of an embryo, through the development of a fetus, to birth. This process can be divided into three distinct stages: the pre-embryonic stage, the embryonic period, and the fetal period. Birth is followed by a long postnatal period.
Why is the prenatal period important in child development?
While you might think of child development as something that begins during infancy, the prenatal period is also considered an important part of the developmental process. Prenatal development is a time of remarkable change that helps set the stage for future psychological development.
How long does the embryonic period last?
Next, the embryonic period lasts from implantation until about 8 weeks from the time of conception. This is the most crucial period of prenatal development. During the embryonic period, cells begin to take on different functions through a process called differentiation.
Which is the longest period in prenatal development quizlet?
In order, the three main periods of prenatal growth are: germinal, embryonic, fetal. The longest period of prenatal development is the embryonic period.
Which of the three stages is the longest?
Three stages The dilation (opening) stage is the longest, while the expulsion (pushing out) stage lasts 30-60 minutes, and the placental stage takes from a few minutes to up to 60 minutes. Various factors influence how long it takes to give birth: Whether you've given birth before or not.
What is the span of prenatal period?
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 are the 3 prenatal periods?
From beginning as a one-cell structure to your birth, your prenatal development occurred in an orderly and delicate sequence. There are three stages of prenatal development: germinal, embryonic, and fetal.
Which stage of prenatal development is the shortest?
the Germinal StageWhat Is the Germinal Stage? Figure 23.2. 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.
During which trimester does the fetus grow most rapidly quizlet?
The third trimester encompasses months 7 to 9 of pregnancy. During this time period, the fetus grows most rapidly and gains weight, and the mother's body prepares for the eventual labor and delivery.
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.
Does life start at conception?
Life Begins at Fertilization with the Embryo's Conception. "Development of the embryo begins at Stage 1 when a sperm fertilizes an oocyte and together they form a zygote." "Human development begins after the union of male and female gametes or germ cells during a process known as fertilization (conception).
During which trimester does the fetus grow most rapidly?
Second trimester (14 weeks and 0 days to 27 weeks and 6 days): The time of rapid growth and development. Third trimester (28 weeks and 0 days to 40 weeks and 6 days): The time when the fetus's weight increases and the organs mature so they will be ready to function after birth.
Why is prenatal period the most crucial period in development?
This is the embryonic period of prenatal development. This stage lasts from implantation until about 8 weeks from the time of conception (or the 10th week of pregnancy). This is the most important time of prenatal development because the embryo is developing the foundations for a healthy baby.
During which prenatal period are the eyes most at risk?
At the end of the 12th week, the fetus is about 3 inches long and weighs about 28 grams. 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 hiccupping develop during the 5th month.
Which stage of cell cycle is the longest?
InterphaseInterphase is the longest part of the cell cycle. This is when the cell grows and copies its DNA before moving into mitosis.
What are the 3 stages of the cell cycle quizlet?
What are the three stages of the cell cycle? The three stages of the cell cycle is interphase, mitosis, and cytokinesis. Summarize what happens to chromosomes during the stage of the cell cycle in which the nucleus divides.
What are the three stages of the cell cycle quizlet?
Terms in this set (3)Interphase. Longest part of cell cycle, cell grows and develops and function parts in our body. Almost at the end of interphase, DNA and chromosomes double.Mitosis. Stage in cell cycle where, cell divides in to two nuclei.Cytokinesis. The two daughter cells create as the cytoplasm divides.
What are the stages of prenatal development?
This time period is divided into different categories of development. The 3 primary stages of prenatal development are the germinal period, the embryonic period, and the fetal period. Each of these stages is important for reaching the ultimate goal of a healthy baby.
Why is prenatal development important?
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.
What is the Brochure of Development?
Brochure includes information about the development through the germinal, embryonic and fetal periods
What is the term for the zygote that is implanted into the uterus?
Once it reaches the uterus, the zygote becomes what is called a blastocyst , and it begins to implant into the wall of the uterus. The germinal period ends when the blastocyst is fully implanted into uterine tissue.
How long is the germinal period?
Prenatal development is divided into three different categories of development. The first 2 weeks of development is the germinal period. The germinal period begins with conception and ends when the blastocyst is fully implanted into uterine tissue.
When does the germinal period end?
The germinal period begins with conception and ends when the blastocyst is fully implanted into uterine tissue. Next, the embryonic period lasts from implantation until about 8 weeks from the time of conception. This is the most crucial period of prenatal development.
What is the process of differentiation?
Through a process called differentiation, cells begin to take on different functions. One of the first examples of this is a division between the cells that will make up the placenta and the cells that will make up the baby. After this, a process called gastrulation forms three layers called germ layers.
How are blastomeres transported?
The cohering blastomeres are transported downward chiefly, at least, by muscular contractions of the tubal wall. Such transport is relatively rapid until the lower end of the tube is reached, and here cleavage continues for about two days before the multicellular cluster is expelled into the uterus. The full reason for this delay is not clear, but it serves to retain the cleaving blastomeres until the uterine lining is suitably prepared to receive its prospective guest.
What is the female pronucleus of a ripe egg?
Following the separation of the second polar body (one or two polar bodies are produced during division), the oocyte nucleus typically reconstitutes and is then called the female pronucleus of the ripe egg. It is now ready to unite with its male counterpart and thereby consummate the total events of fertilization.
What is the term for a cell that tries to penetrate an egg to fertilize it?
A sperm cell attempting to penetrate an egg (ovum) to fertilize it.
What is prenatal development?
Prenatal development, also called antenatal development, in humans, the process encompassing the period from the formation of an embryo, through the development of a fetus, to birth (or parturition ). human fetus; prenatal development. An ultrasound image of a human fetus. age fotostock/SuperStock.
What is the mitotic spindle?
During mitosis (ordinary cell proliferation by division), the centromeres attach to a bundle of microtubules known as the mitotic spindle, which is formed by centrioles (cylindrical cell structures).
Where does sperm go in the oocyte?
Once within the periphery of the oocyte, the sperm advances toward the centre of the cytoplasm; the head swells and converts into a typical nucleus, now called the male pronucleus, and the tail detaches.
How many chromosomes are in each pronucleus?
Each resolves its diffuse chromatin material into a complete single set of 23 chromosomes. Each chromosome is composed of two chromatids held together by a centromere.
