Embryo Exam 2 Flashcards
What hormone is involved in detection and maintaining a pregnancy
Human Chorionic Gonadotropin (HCG)
Differentiation of the embryoblast begins with what
Formation of a Bilaminar Disc
Columnar cell layer facing the cytotrophoblast
Epiblast
Cuboidal cell layer facing the blastocyst cavity
Hypoblast
Fluid filled space between the epiblast and the cytotrophoblast
Amniotic Cavity
Cells formed from the cytotrophoblast, lining the upper region of the amniotic cavity, and produce amniotic fluid
Amnioblasts
Cells from the hypoblast line the exocoelomic cavity with exocoelomic membrane to become
The primary umbilical vesicle (yolk sac)
Maternal blood lacunae flow into the syntophoblastic lacunae on the 12th day known as
Primitive Uteroplacental Circulation- through lacunar networks
What gap junction protein is critical in angiogenesis at the implantation site of placenta and uterine endometrium for maintenance of pregnancy
Connexin 43
What 2 hormones influence the formation of blood vessels in the endometrium stroma
Estrogen and progesterone
What kind of rxn does the uterus have to the implantation and development of teh conceptus
A Decidual rxn
Physical rxn to conceptus (blastocyst) implants
Endometrial cells transform glycogen and lipids in cytoplasm for nutrition
Immunological rxn to endometrial connective tissue cells accumulate glycogen and lipids
Immunologically privileged site for the conceptus (decidual rxn)
What is the beginning of the mouth and organizer of the head region
The prechordal plate
What is gastrulation
Process by which the bilaminar germ disc is converted to trilaminar
Day 15 epiblast cells proliferate on the midline of the disc and form a narrow streak that runs down the disc called…
Primitive Streak
Middle of the primitive streak forms the…
Primitive Groove
At the the end of the primitive groove is the…
Primitive Pit
Epiblasts at the top layer form the
Ectoderm
Epiblasts that migrate through the primitive groove and develop a middle layer called
Mesoderm
Epiblasts that displace the hypoblast cells to develop a lower layer called the…
Endoderm
What is organogenesis
Process of developing organ systems
Ectoderm gives rise to
Epidermis CNS, PNS, Eyes, Ears, Neural crest cells, Connective tissue of the head
Mesoderm gives rise to
All skeletal m., Blood cells, visceral smooth m. coats, lining of body cavities, reproductive, CV system, and most connective tissue of the body
Endoderm gives rise to
Epithelial lining, lines glands and organs dealing with GI, and glandular cells of liver and pancreas
The caudal area develops what
Cloacal plate. which later forms the openings of the anus, urinary, and genital tracts
What is the area for the future heart
Cardiogenic Area
What can occur if remnants of the primitive streak remain
Give rise to a tumor
What is the most common tumor in newborns
Sacroccygeal Teratoma
What is the notochord
Mesoderm cells that migrate cranially to create a midline cord of cells
What is neurulation
Begins with the folding called neurulation and it’s a Process of conversion of the neural plate from a neural tube happens in the beginning of the fourth week
What is the function of neurophores
Allows for communication with the amniotic cavity through large openings
What is Spina bifida and anencephaly
An interruption of the tube closure
What are somites
Segmented mesodermal tissue along neural tube, which gives rise to vertebral column, voluntary m., connective tissue, and skin
What is the primary chorioinic villi
Core of cytotrophoblast cells covered by syntrophoblasts
What is the secondary chorionic villi
Mesodermal cells penetrate the core of the cytotrophoblast cells of the primary villi
What is the tertiary chorionic villi
Mesodermal core differentiates into blood and blood vessels
What is Perinatology
Study of fetus and newborn as patient
What is Fetology
Studies concerned with the fetus
Amniocentesis
After 14 weeks, sampling of amniotic fluid by inserting a hollow needle into mother’s abdominal and uterine wall
Indicators for Amniocentesis
Later maternal age 38+, previous chrmosomal abnormalities, family hx, or carrier of inborn metabolic disorder
Schedule of ultrasounds
7-8th week confirm and look for ectopic, 18th-20th malformations mult. pregnancy and postition of placenta, and 34th week fetal size growth and position
What is a Fetoscopy
Fiber optics to scan entire fetus
Fetoscopy risks
Higher risk factors, 5-6% of fetal death or spontaneous abortions can be up to 12%, and radiation exposure-thyroid abnormalities
Chorionic Villus Sampling
Biopsy of the chorionic villi by inserting a needle into the abdominal and uterine wall. 8th week. 2-3% fetal death
Alpha fetoprotein
Glycoprotein synthesized in fetal liver, yolk sack and gut
What is the Decidua Basalis
Where the placenta is attached
What is the Decidua Capsularis
At the aembryonic (opposite the embryo) end
What is the Decidua Parietalis
Opposite to the sides of implantation
The Amniochorionic Membrane is aka
The Amniotic Sac
Weight of the placenta
1/7 of the maternal weight
Fetal circulation Deoxy blood
Deoxy blood goes through arteries. The lungs are bypassed and do not receive oxygen
Umbilical Vein
Fetal blood is oxygenated through the placenta and passes into the umbilical vein
Rate of blood flow and fetal hypoxia
Rate is pretty high, but fetal hypoxia can occur due to acute reduction in maternal blood flow
4 layers of Placenta Membrane
Syntrophoblasts, Cytotrophoblasts, Connective tissue layer, Endothelium of fetal capillaries
How are materials transported across the placental membrane
Simple, facillitated, Active xport, or pinocytosis
Functions of Amniotic Fluid
Movement, Growth, prevents adherence, protections, nutrition, maintain temp, and lubricate cervix during birth
Oligohydramnios
400mL or less of amniotic fluid
Polyhydramnios
2000mL or more of amniotic fluid
Characteristics of the Umbilical cord
1-2 cm diameter, 50-60 cm length, Contains 1 vein and 2 arteries
When the yolk sac/secondary umbilical vesicle starts to degenerate, it retains a portion to become…
Vitelline vessels
What is Allantois
These vessels become urachus in the fetus, or the median umbilical ligament in adults
