State the functions of the umbilical cord placenta amniotic sac and amniotic fluid
#141 The development of the fetus
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Credit: thomasreynoldsblog The blastula develops into an embryo and some of the cells form a placenta, linking the embryo with the uterus lining. Organs such as the heart develops and, after 8 weeks, the embryo is called a fetus. Growth of the fetus requires a good supply of nutrients and O2. This is achieved through the link between the placenta and the mother’s blood supply in the uterus lining. The placenta is soft and dark res, and has finger-like projections called villi. The villi fit closely into the uterus wall.
1. Umbilical cord
2. Placenta
Brings blood supply of fetus close to mother’s
Prevents mixing
The fetus in the amniotic sac. Credit: preventdisease.com Amniotic
sac: membrane from embryo cells: encloses fetus, prevents entry of bacteria
Answer a) i) A, umbilical cord ; B, vagina ii) Tree functions from: iii) Helps prevent bacteria passing from mother to fetus, the blood group of mother and fetus may be different.
Placental Structure, Circulation, and FunctionPlacental structureThe placenta has a pancake-like appearance, with 2 sides:
2 placentas: Placental circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment
Placental barrierThe placental barrier is a selectively permeable membrane separating the maternal and fetal blood. The barrier is comprised of the following layers:
Circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment within chorionic villi and the components of the placental barrier Image by Lecturio. License: CC BY-NC-SA 4.0Functions of the placentaThe table lists the many critical functions of the placenta for the fetus. Table: Functions of the placenta
Transport across the placental barrier Image by Lecturio. License: CC BY-NC-SA 4.0Related videosPlacental DevelopmentSteps in placental development:
Implanted blastocyst Blastocyst A post-morula preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper. Fertilization and First Week Image by Lecturio. License: CC BY-NC-SA 4.0Fetus of about 8 weeks, enclosed in the amnion Related videosUmbilical CordDefinitionThe umbilical cord connects the fetus to the placenta. The cord contains 2 arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology and 1 vein and extends from the fetal umbilicus to the fetal surface of the placenta. Umbilical cord structure
Cross section of the human umbilical cord Amniotic CavityThe amniotic cavity Amniotic cavity Embryoblast and Trophoblast Development is a fluid-filled cavity that encases the developing embryo Embryo The entity of a developing mammal, generally from the cleavage of a zygote to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the fetus. Fertilization and First Week/fetus; the fluid is called amniotic fluid.
Initial development of the amniotic cavity Amniotic cavity Embryoblast and Trophoblast Development during implantation Implantation Endometrial implantation of embryo, mammalian at the blastocyst stage. Fertilization and First Week Image: “2907 Embroyonic Disc, Amniotic Cavity Amniotic cavity Embryoblast and Trophoblast Development, Yolk Sac-02” by OpenStax College. License: CC BY 3.0Development of the
amniotic cavity Amniotic cavity Embryoblast and Trophoblast Development between the 7th week and 4th month of development: Placenta and Childbirth
Delivery of the placenta via gentle downward traction on the umbilical cord and countertraction on the uterus
Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes:
Anatomy: Related videosClinical Relevance
Placenta previa Placenta Previa Abnormal placentation in which the placenta implants in the lower segment of the uterus (the zone of dilation) and may cover part or all of the opening of the cervix. It is often associated with serious antepartum bleeding and premature labor. Placental Abnormalities Image: “2906 Placenta Previa-02” by OpenStax College. License: CC BY 3.0Types of abnormal placentation Image by Lecturio. License: CC BY-NC-SA 4.0References
What is the function of placenta and umbilical cord?The placenta is an organ that develops in the uterus during pregnancy. This structure provides oxygen and nutrients to a growing baby. It also removes waste products from the baby's blood. The placenta attaches to the wall of the uterus, and the baby's umbilical cord arises from it.
What are the functions of the amniotic fluid and the umbilical cord during pregnancy?The umbilical cord transports oxygen and nutrients from you to the fetus and could become squished without amniotic fluid. Amniotic fluid contains antibodies to help strengthen the fetal immune system. The fetus practices breathing and swallows amniotic fluid to help develop its lungs and digestive system.
What are the functions of the umbilical cord?The umbilical cord is considered both the physical and emotional attachment between mother and fetus. This structure allows for the transfer of oxygen and nutrients from the maternal circulation into fetal circulation while simultaneously removing waste products from fetal circulation to be eliminated maternally.
What are the 5 functions of amniotic fluid?Amniotic fluid is responsible for: Protecting the fetus: The fluid cushions the baby from outside pressures, acting as a shock absorber. Temperature control: The fluid insulates the baby, keeping it warm and maintaining a regular temperature. Infection control: The amniotic fluid contains antibodies.
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