Conception and Fetal Development Flashcards
the process of egg (ovum) formation
oogeenesis
the process of sperm formation
spermatogenesis
Two protective layers
Considered fertile for about 24 hours
ovum
removal of sperm’s protective coating
Capacitation
a cap on the sperm
acrosome
first cell of the new individual
zygote
16 cells
morula
occurs 6-10 days after conception
implantation
primary germ layers
Ectoderm
Mesoderm
Endoderm
lasts from day 15 until 8 weeks after conception
Most critical time for development
embryo
Substances or exposure that causes abnormal development
teratogens
Two fetal membranes that surround the developing embryo
Chorion
Amnion
functions of amniotic fluid
Warmth
Prevention of contractures
Movement
Respiratory (breathing) and renal development (urination)
what is important to monitor about amniotic fluid
Volume is important
Oligohydramnios- too little
Polyhydramnios (hydramnios)
Aids in transferring maternal nutrients and oxygen for the first 5-6 weeks
yolk sac
components of umbilical cord
Wharton’s jelly
Vessels: 2 arteries and 1 vein
when is the structure of the placenta complete
12th week
functions of the placenta
Endocrine gland function:
Multiple metabolic functions
Adequate circulation necessary for placental function
Human chorionic gonodotropin (HcG)
lasts from 9 wks till pregnancy ends
fetus
the capability of the fetus to survive outside the uterus
viability
components specific to fetal circulation
Ductus arteriosus
Ductus venosus
Foramen ovale
describe the fetal respiratory system
Pulmonary surfactants
L/S ratio: used to determine fetal lung maturity
when does sex differentiation begin
seventh week
from 2 mature ova
dizygotic
one ova that divides
monozygotic
monozygotic but cleavage incomplete
conjoined
how common are twins
1 in 43 births
the condition was present at birth
congenital
possible causes of congenital issues
Environmental factors Poor maternal nutrition Teratogen exposure Inadequate folic acid Genetics
how many days does human gestation last
approximately 280 days after the last menstrual period or 266 days after conception
upper triangular portion of uterus
corpus
dome-shaped top of uterus
fundus
lower cylindrical portion of uterus
cervix
lower uterine segment that separates the corpus from the cervix
isthmus
aka uterine tubes
Fallopian tubes
layers of the uterine wall
Endometrium
Myometrium
Peritoneum (partial)
primary purpose of the bony pelvis
Protects the pelvic structures
Accommodates the growing fetus during pregnancy
Anchors the pelvic support structures
two parts of bony pelvis
False pelvis (upper portion-wider) True pelvis (lower
Aid in keeping cervix closed during pregnancy
circular fibers of the uterine muscle
