Embryonic Development Quiz

Pregnancy and Fetal Development

• Determining the timing of a pregnancy relies on understanding the starting point and is crucial for medical consultations.
• Early pregnancy medical appointments involve assessing medical history, genetic concerns, and conducting various diagnostic tests.
• The process of pregnancy involves sequential stages such as fertilization, implantation, embryogenesis, fetal development, labor, and birth.
• The morula, formed through several divisions, is a solid ball of cells surrounded by the zona pellucida from the original oocyte.
• The blastocyst, formed around day 3-4 after fertilization, consists of a fluid-filled chamber and a layer of cells that will develop into the embryo.
• Implantation generally begins between day 7-10 post-fertilization, involving trophoblast invasion and the deciduoma response.
• The immune system's response to fetal tissues involves the detection of foreign cells through histocompatibility proteins on white blood cells.
• Early embryonic development involves the differentiation of the pre-embryo into two tissue layers and gastrulation, creating the three primary germ layers.
• Embryonic membranes, including the yolk sac, amnion, allantois, and chorion, play essential roles in supplying blood cells to the embryo and forming the placenta.
• The placenta, derived from fetal and maternal tissues, facilitates gas and waste exchange between the developing fetus and the carrier.
• Exchange between the fetus and carrier is limited to molecules less than 500 molecular weight, creating microchimerism and potential links to autoimmune disorders.
• In twin pregnancies, differences exist in the formation of placentas and amnions, and genetic imprinting affects the expression of imprinted genes depending on their source (egg or sperm).