Exam 1 part 5 Flashcards
developmental process by which the mature human ovum is formed, haploid number of chromosomes
Oogenesis
Process by which the cell divides into two genetically identical daughter cells each with 46 chromosomes
mitosis
Cellular division for sexual reproduction
Haploid results in 23 chromosomes
meiosis
degenerates without implantation
corpus luteum
when does an unfertilized oocyte die
12-24 hours after ovulation
how long do sperm survive in the uterus
48-80
sperm swimming penetrates the
Corona radiata
sperm binding to the ____ is critical
Zona pellucida ZP3
membrane fusion
acrosomal reaction
releases hydrolytic enzyme (acrosin is a membrane bound seine protease)
everts acrosomal reaction
fertilization occurs in the ____ of the fallopian tube
ampulla
high____ levels increase contractibility of tubes to help move ovum
Helps thin cervical mucous
estrogen
when is the morula is 16 cell solid sphere
3 days
when is it a blastocyte
5 days
inner cell mass
embryoblast= embryo
outer layer of cells/ trophoblast
becomes part of the placenta
pre embryonic
1-14 days
embryo
time of fertilized ovum to fetus 2nd-8th week
fetus
from 8th week until birth 40 weeks
all tissue products of conception (embryo, fetal membranes and placenta)
conceptus
the innermost of the three primarily germ layers of an animal embryo, developing into the gastrointestinal tract, the lungs, and associated structures
also called hypoblast
Endoderm
an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mothers blood supply
placenta
is the outer layer of the early embryo
It emerges first and forms from the outer layer of germ cells
ectoderm
the middle embryonic germ layer, lying between the ectoderm and the endoderm from which connective tissue, muscle, bone, and the urogenital and circulatory system develops
mesoderm
when do the ectoderm, mesoderm, and endoderm form
between days 15-18
the endometrium during pregnancy except at the site of the implanted blastocyst
Decidua parientalis- vera
what does the endoderm create
lungs, intestines, bladder
Three shunts bypass fetal liver and lungs
Ductus venosus
Foramen ovale
Ductus arteriosus
placental functions
Metabolic
endocrine
immunologic
transport
Foramen ovale
rt atrium/ lt atrium
ductus arteriosus
pulmonary artery to aorta
Protection of the fetus from pathogens
Large bacteria are prevented but many bacteria and viruses are smaller and do cross
Maternal igG cross
immunologic placental functions
Mechanisms include: passive diffusion, facilitated diffusion, active transport, pinocytosis, bulk flow, accidental capillary breaks, independent movement
transport placental functions
Physical protection of fetus Uniform pressure Even temperature fluid to drink and breath medium of movement wedge for childbirth excretion and collection system
amniotic fluid function
from it develops the chorionic villa that enter the endometrium with implantation-gives rise to placenta
blastocyte
the innermost fetal membrane: a thin thansparent sac that holds the fetus suspended in the liquor amnii – or amniotic fluid- grows rapidly and by the end of the 3rd month fuses with chorion- forming the amniotic sac– bag of waters
Amnion
is a membranous sac attached to an embryo, providing early nourishment -first appears during the fifth week of pregnancy and grows to be no larger than 6 mm. Yolk sacs larger than 6 mm are usually indicative of an abnormal pregnancy. Failure to identify (with transvaginal ultrasound) a yolk sac when the gestational sac has grown to 12 mm is also usually indicative of a failed pregnancy. Is early site of homeogenesis
yolk sac
the part of the decidua that surrounds the chorionic sac
Decidua capsularias
the part of the uterine decidua that unites with the chorion to form the placenta
Decidua basalis
causes of longer umbilical cord
vascular occlusion
thrombi, fetus, and true
oxygenated fetal blood via 1 umbilical
vein
oxygen depleted fetal blood via 2
arteries
makes glycogen, fatty acids, cholesterol, and enzymes
Produces ammonia and lactate that stimulate the fetal liver
Metabolic placental functions
HCG, hPL, estrogen, progesterone, various growth factors, oxytocin, various pituitary
endocrine placental functions
can breath/ lacks surfactant
28 weeks from LMP
how big is an embryo at four weeks
4 mm long
inhibited fetal swallowing
polyhydramnios
fetal urinary obstruction or renal agenesis
oligo
how long is the umbilical cord
55cm
extracellular matrix consisting of specialized connective tissue
whartons jelly
causes of extremely short umbilical cord
abruptio placenta
unterine inversion
fetal heart begins to beat
4 weeks from conception
all organs are formed
8 weeks from conception
heart beat heard with doppler
9-12 weeks from LMP
babys sex may able to be seen
11 weeks from LMP
mother feels movement
17-20 weeks from LMP
respiratory movements
24 weeks from LMP
brain before lungs
cephalcocaudal
arms before fingers
proximodistal
