conception and fetal development part 2 Flashcards
identical (monozygotic) twins develop from a single _____ that divides and forms 2 developing cellular masses
ovum
maternal part of placenta is on the ______ attached to the mother
endometrium
the fetal part of the placenta is inside the ___ _____
amniotic fluid
development of placenta and circulation does not begin until the _____ week of embryonic development
3rd
maternal portion of placenta consists of _____ ____ and its circulation
decidua basalis
the fetal portion of the placenta consists of the ___ _____ and their circulation
chorionic villi
the placenta produces _____, _____, and ____ _____
glycogen
cholesterol
fatty acids
the placenta helps with fetal ____, ____, and ______
respirations
nutrition
excretion
in the ____ week of development, the placenta produces more than 50% of estrogens in maternal circulation
7th
in the 10th week, the placenta takes over production of _______ from corpus luteum
progesterone
in the 10th week, the corpus luteum secretes progesterone in large quantities, reaching levels of more than _____mg/day late in pregnancy
250
if a pt has a miscarriage, _____ levels will go down
progesterone
in the 11th week, the placenta produces enough _____ and _____ to maintain pregnancy
progesterone
estrogen
at a newborns first breath, the _____ ____opens
ductus arteriosus
if the foramen ovale isn’t closing properly, a ____ may be suspected
murmur
the _____ ____ closes when the infant breaths
foramen ovale
____ ____ constricts as arterial O2 rises
ductus arteriosus
_____ ____ constricts when the flow of blood from the umbilical cord stops
ductus venosus
outer germ layer secretes ______
fluid
the outer germ layer, becomes the ____ and its membranes
placenta
during germ layer development, the fetus forms from the _____ _______
embryonic disk
during germ layer development, _____ is responsible for embedding in the uterus
trophoblast
amniotic cavity lined with _____ cells
ectoderm
yolk sak lined with ______ cells
endoderm
during week ____ of fetal development, the heart begins the beat
4
main external features of fetus develop by the _____ week
8th
during weeks 4 and 5, _____ form on either side of the embryos midline that will form the spinal column
somites
during weeks 4 and 5, partitioning in heart occurs with dividing of ______
atrium
during weeks 4 and 5, _____ and _____ buds are well developed
arm
leg
during weeks 4 and 5, the brain has ___ differentiated areas
5
during weeks 4 and 5, 10 pairs of ____ ____ are recognizable
cranial nerves
at 6 weeks, the ____ has developed
trachea
at 6 weeks, the trachea’s ____ end is bifurcated for the beginning of lung formation
caudal
at 6 weeks, the trachea’s caudal end is ____ for the beginning of lung formation
bifurcated
at ____ weeks both arms and legs have digits
6
at 6 weeks, the fetal ____ has most of its definitive characteristics
heart
at ___ weeks fetal circulation begins to be established
6
at 6 weeks, the _____ starts to produce blood cells
liver
at ____ weeks, every organ system and external structure that will be found in full-term newborn is present
8
at _____ weeks tooth buds appear
12
at ____ weeks the fetus can curl fingers toward their palm and will have spontaneous movements
12
at 12 weeks, _____ tract completes its development and _____ begin to produce urine
urogenital
kidneys
at 12 weeks, _____ are produced primarily by the liver
RBCs
fetal heart begins to beat at 4 weeks, but cannot be heard until ___ weeks
12
weeks ___-____ are periods of rapid growth
13-16
at 13-16 weeks, ____ begins to develop, especially on the head
lanugo
_____ ___ babies have more lanugo
pre-term
at 13-16 weeks, the fetus _____, and ____ and _______ amniotic fluid
stretches
sucks and swallows
at 13-16 weeks, the fetus produces _____
meconium
the mother will be able to feel quickening at _____ weeks
18
at 18 weeks, the eyes and face are ___ and the ears are ______
forward
higher
at 20 weeks, ______ ______ of brown fat make skin less transparent
subcutaneous deposits
at 24 weeks, the ____ are structurally complete and will soon open
eyes
____ and ____ reflexes present at 24 weeks
grasp
startle
____ _____ is a cheesy substance that helps protect babies skin
vernix caseosa
at 24 weeks, the fetus’ entire body is covered with _____ _____
vernix caseosa
at 24 weeks the _____ in the lungs are just beginning to form
alveoli
at ____ weeks a has a good chance of surviving if born
36
at 24 weeks, the lungs begin to produce _____
surfactant
at 28 weeks, the _____ is developing rapidly
brain
at 30 weeks, the ____ ___ reflex is present
papillary light
at 30 weeks, the CNS has matured enough to direct _____ _____ movements and partially control _____ _____
rhythmic breathing
body temp
at 30 weeks, bones are fully developed, but are _____ and ______
soft
flexible
at 36 weeks, ____ begins to disappear
lanugo
____ weeks is considered full-term
38
at 38-40 weeks, the skin is ______ and has ____, polished look
pink
smooth
at 38-40 weeks lanugo is only on ____ _____ and ________
upper arms
shoulders
at term, the fetus assumes a position of comfort, usually _____ down
head
at term, the fetus has well-flexed ____ and _____
extremities
head
deficiency of ____ ____ prenatally can increase the incidence of neural tube defects
folic acid
deficiency of folic acid prenatally can increase the incidence of _____ _____ defects
neural tube
