ANP 1107A Reproductive System Lecture Four Flashcards
how long after ovulation is an egg capable of being fertilized
-12-24 hours
how long is sperm viable in the reproductive system
-one week
-fertilization is 24-48 hours
what is capacitation
-change in sperm that typically occurs inside the womans body
-require before fertilization can occur
what happens to sperm after capcitation?
-increased rate of flagerllar
-accelerated motility pattern
what does seminal fluid contain?
capacitation inhibiting factors
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Why is it important that this happens only after sperm have bound to the
zona pellucida?
if enzymes are released before sperm binds = no chance of fertilization
what is polyspermy?
-egg that has been fertilized by more than one sperm
-not viable because there are more than two copies of each chromosome
what happens to the oocyte after one sperm goes through?
-hardening of zona pellucida
-clipping off sperm receptors to avoid polyspermy
fast block to polyspermy
oocyte membrane block
slow block to polyspermy
crotical reaction
when does meoisis resume?
after the sperm penetrates the secondary oocyte
what is pronucleus?
nucleus of sperm/egg post-fertilization but prior to fusion
when does the zygote form?
when chromosomes from male and female intermix
what is a zygote?
a diploid cell from the fusion of two haploid gametes
what is a blastocyst?
a hollow ball of cells with a cluster of cells inside known as the inner cell mass
what structure hatches from the zona pelluicda?
blastocyst
when does implantation occur?
6 days after fertilization
what is the trophoblast?
cells forming from the outer layer of the blastocyst
what does the trophoblast become?
placenta
what does the inner cell mass become?
embyro
when is implantation complete?
day 10
at 4.5 weeks, what can be seen from the embryo?
-limb buds
-eyes and mouth
-cardiovascular system
what is the yolk sac?
-source of red blood cells for fetus
when is the germinal period?
conception to 2 weeks
when is the embyronic period?
3-8 weeks
when is the fetal period?
9 weeks to term
what period is most impacted by teratogens?
embyronic period
structures of the endoderm?
-epithelial linings of digestive
-respiraotry tracts
structures of the mesoderm?
-kidneys
-heart
-blood vessels
-CT of limbs
what structures arise from the ectoderm?
-epidermis
-brain
-spinal cord
-hair
-nails
what is placentation?
formation of placenta
maternal and fetal blood supplies not
in direct contact
- nutrients, gasses, wastes diffuse through
trophoblast layer
mesenchyme
fetal capillary endothelium
normal term placenta is?
~500g
measures 15-20 cm, 2-3 cm thick
how many arteries and veins does the umbilical cord have?
2 arteries 1 vein
what is the foramen ovale?
opening between right and left atria
what is the ductus venosus?
shunt from umbilical cord
bypasses liver and takes blood straight to the brain and heart
umbilical arteries are
dexygeneted
umbilical veins are
oxygenated
what hormone is made exclusively in the placenta
human choronic gondatropin
when is hCG present in maternal fluid?
3-8 days after fertilization
function of hCG?
-stimulates production of estrogen and progesterone by CL
-maintain pregnancy until placenta takes over at 12 weeks
without hCG, what would degenerate?
corpus luteum
pregnancy tests used today test the presence of what?
human choronic gonadotropin hCG
human placental lactogen (hPL) is similar to what?
human choronic somatommotropin (hCS)
when does the placenta start ot secrete hCS?
first trimester
levels increase until delivery
what does hCS do?
-breast developing in preparation for postnatal lacation
-supports fetal bone growth
-makes glucose avilable to fetus by reduce insulin sensitity
what is gestational diabetes?
abnromal blpud glucose maintance during pregnancy
- leads to temporary diabetes
what does the placenta convert circulating androgens to?
estrogen
what does estrogen do
- maintains uterine enometrium
- breast development
when is blood pressure lowest for a pregnant mother?
24 weeks
what is myocardial hypertrophy?
increase in workload = thickening in muscle
