Term
| What is the function of Decidual Cells? |
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Definition
| Forms a protective scar tissue around the embryo (protection from mother immune response) and produce prolactin |
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Term
| What does the hormone prolactin do? |
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Definition
| Stimulate mammary development |
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Term
| What is the Decidual Basalis? |
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Definition
| Point where the endometrium is being eaten by the syncytiotrophoblast |
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Term
| What is the Decidual Capsularis? |
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Definition
| Decidual cells that form a capsule around the embryo. These cells are eventually pushed off |
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Term
| What is Decidual Parietalis? |
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Definition
| The outer layer of Decidual Cells |
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Term
| How is the lumen of the uterus closed off? |
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Definition
| Fusion of Decidual Cells (Parietalis and Capsularis) |
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Term
| What is the bilaminar disc? |
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Definition
| The bilaminar disc is the differentiation of the inner-cell mass of the blastocyte. The bilaninar disc differentiates into the Epiblast and the Hypoblast |
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Term
| The epiblast gives rise to what kind of tissue? |
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Definition
| Extraembryonic and embryonic tissue |
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Term
| The hypoblast gives rise to what kind of tisse? |
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Definition
| Only extraembryonic tissue |
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Term
| What is the amniotic cavity? |
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Definition
| A fluid filled cavity formed in the epiblast during Week 2 of development |
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Term
| How is the embryo nourished in the early stages of week 2? |
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Definition
| The syncytiotrophoblast grows out towards maternal blood vessels and glands and the products diffuse back to the embryo. Early nourishment is then provided by yolk sacs |
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Term
| What is Heuser's Membrane? |
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Definition
| Heusers Membrane is an outgrowth of hypoblast cells that form the primary yolk sac within the blastocele |
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Term
| What is the extraembryonic Reticulum? |
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Definition
| This is a extracellular matrix secreted by the hypoblast that form a lining between Heuser's Membrane and the Cytotrophoblasts |
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Term
| What is the extraembryonic splachnic mesoderm? |
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Definition
| This is cellular tissue from the epiblast that uses the extraembryonic reticulum to line the outside of Heuser's membrane |
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Term
| What is extraembryonic somatic mesoderm? |
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Definition
| This is epiblast cells that use the extraembryonic reticulum to line the inside of the cytotrophoblast |
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Term
| What developes in the extraembryonic mesoderm in week 2? |
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Definition
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Term
| What signals the growth of vitelline blood vesels? |
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Definition
| The yolk sac (cells from Heuser's Membrane) |
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Term
| What is the purpose of Vitelline blood vesels? |
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Definition
| Drain blood from the yolk sac |
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Term
| What do vitelline blood vessels eventually develop into? |
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Definition
| blood vessels of the midgut: hepatic veins, inferior portion of the inferior vena cava, portal vein, superior mesenteric vein |
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Term
| How does the chorionic cavity form? |
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Definition
| Lacunae develop in the extraembryonic reticulum and eventually fuse to create the cavity |
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Term
| How does the definitive yolk sac form? |
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Definition
| Hypoblast cells begin to line the inside of Heuser's membrane and eventually force out and pinch off the primary yolk sac |
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Term
| What suspends the amnionic caivty and the definitive yolk sac? |
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Definition
| A thick connecting stalk of extraembryonic tissue. This will be the site of umbilical circulatory development |
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Term
| What hormones do syncytiotrophoblasts secrete? |
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Definition
hCG, human placental lactogen, human chorionic somatomammotropin, relaxin, estrogen, and progesterone
hCG is the LH like factor that keeps the Corpus Luteum alive
Syncytiotrophoblasts eventually take over the hormonal requirements of the Corpus Luteum |
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Term
| What is the allantois? What is it's function? |
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Definition
the allantois is part of the developing human conceptus.
the allantois handles some waste management but is most credited for being the signal pathway for the development of umbilical blood vessels. |
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Term
| What happens to the allantois? What is the clinical relevance? |
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Definition
| Eventually the allantois becomes the urachus (vestigial organ of development). If the allantois does not scar over properly it can cause a cyst or a fistula |
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Term
| What is Meckel's diverticulum? |
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Definition
a diverticulum is an outpouching of a fluid filled vessel in the body.
Meckel's diverticulum is a diverticulum arising from the yolk sac remaining on the ileum |
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Term
| What are chorionic villi? |
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Definition
| Chorionic villi are outgrowths of extraembryonic mesoderm that serve the purpose of increase surface area contact with maternal blood. |
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Term
| What is primary stem villus? |
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Definition
| Initial stage in the development of chorionic villi. At this stage they are small and unvascularized |
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Term
| What is the hallmark of secondary stem villi? |
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Definition
| The hallmark of secondary stem villi are that they have been invaginated with extraembryonic mesoderm |
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Term
| What is the hallmark of tertiary stem villus? |
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Definition
| Tertiary stem villus are vascularized |
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Term
| umbilical veins carry what kind of blood? |
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Definition
|
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Term
| umbilical arteries carry what kind of blood? |
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Definition
| Unoxygenated blood and waste products |
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Term
| What can a fetus pass to a mother? |
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Definition
| C02, Billirubin, Urea, and Water |
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Term
| What can a mother pass to a fetus? |
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Definition
| O2, nutrients, steroid hormones, electrolytes, IgG, Vitamins, White blood cells, Infectious agents, and Teratogens |
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Term
| What are the infectious agents that a mother can pass to a fetus? |
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Definition
| Toxoplasma gondii, Rubella, Varicella-Zoster, Cytomegalovirus, Syphillis, and HIV |
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Term
| What are the teratogens that a mother can pass to an infant? |
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Definition
| Vitamin A, Tobacco, Cocaine, Alcohol, Anticoagulants, Anticonvulsants, Chemotherapeutic drugs |
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Term
| Why are fused placenta's bad for fraternal twins? |
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Definition
| Creates competition for resources, one fetus will exhibit stunted growth |
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Term
| In identical twins, what is the result of division at the zygote level? |
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Definition
| Most normal development with 2 placentas, 2 amniotic sacs, and 2 chorionic sacs |
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Term
| In identical twins what is the result of division of the inner cell mass? |
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Definition
| This will result in one placenta, 2 amniotic sacs, and 1 chorionic sac |
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Term
| In identical twins, what is the result of division at the bilaminar disc? |
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Definition
| Parasitic twins with 1 placenta, 1 amniotic sac, and 1 chorionic sac |
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Term
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Definition
| A case of parasitic twins (division at the bilaminar disc phase) in which one fetus wraps around the other |
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Term
| What is placenta accreta? |
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Definition
| placenta accreta is growth into the myometrium (smooth muscle of the endometrium) |
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Term
| What is placenta percreta? |
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Definition
| placental growth into the perimetrium (outer connective tissue of the endometrium) |
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Term
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Definition
| blockage of the internal os of the cervix |
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Term
| What is the clinical significance of overly deep implantation of the placenta? |
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Definition
| All of the placenta must be removed after birth, if not abnormal growths can occur |
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Term
| What is the significance of Rh factor for pregnant women? |
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Definition
Women who are Rh negative can develop antibodies against fetal blood, this can cause a dangerous spike of billirubin in the system that can cause neurological issues.
This is not a problem with first pregnancies (antibodies still building) but has to be carefully monitored for subsequent pregnancies |
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