A fetus is a cluster of cells that develops between the third and eighth week of pregnancy
Learn how your baby is conceived and how your baby develops inside the mother's womb. Show
WEEK BY WEEK CHANGES Gestation is the period of time between conception and birth when a baby grows and develops inside the mother's womb. Because it's impossible to know exactly when conception occurs, gestational age is measured from the first day of the mother's last menstrual cycle to the current date. It is measured in weeks. This means that during weeks 1 and 2 of pregnancy, a woman is not yet pregnant. This is when your body is preparing for a baby. A normal gestation lasts anywhere from 37 to 42 weeks. Week 1 to 2
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Zygote; Blastocyst; Embryo; Fetus Feigelman S, Finkelstein LH. Assessment of fetal growth and development. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 20. Ross MG, Desai M, Ervin MG. Fetal development, physiology, and effects on long-term health. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 8th ed. Philadelphia, PA: Elsevier; 2021:chap 2. Updated by: John D. Jacobson, MD, Department of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Is the name for the developing organism from two weeks to eight weeks after fertilization?The embryonic period of development lasts from two weeks after conception through the eighth week, during which time the organism is known as an embryo. 1 At the ninth week post-conception, the fetal period begins. From this point until birth, the organism is known as a fetus.
What is the cluster of developing cells following implantation?Implantation • Zygote attaches to the uterine wall. Embryo • Cluster of cells that develop between the 3rd and 8th weeks of pregnancy. Fetus • After the 8th week of pregnancy the developing cells are called a fetus.
Which of the following structures develops first during the period of the embryo?Nervous system.
This is one of the first things to develop. It includes the formation of your baby's brain, spinal cord, and nerves.
What is the term for the thick blood rich tissue that nourishes the fetus during pregnancy?The placenta (pluh-SEN-tuh) is a thick, blood-rich tissue that lines the walls of the uterus during pregnancy and nourishes the embryo. Although the blood supply of the mother and the developing embryo are kept separate, materials diffuse from one blood supply to the other through the umbilical cord.
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