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21. Pregnancy and Parturition
N/A
60
Anatomy
Undergraduate 2
11/29/2012

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Cards

Term
What is the site of fertilization?
Definition
the oviduct
Term
What is fertilin?
Definition
a protein on the plasma membrane of the sperm that binds to integrin from the egg
Term
The binding of integrin and fertilin is ____________ specific.
Definition
species
Term
What happens after fertilin and integrin bind?
Definition
  • a wave of Ca2+ ion propagates along the inner surface of the plasma membrane
  • the calcium wave releases cortical granules into the perivitelline space and causes a flattening of the previously microbillar surface
Term
What is the purpose of the flattening of the previously microbillar surface?
Definition
it keeps additional sperm from interacting with the oocyte
Term
What triggers the final meiotic division of the secondary oocyte?
Definition
penetration of the sperm into the cytoplasm
Term
What is a zygote?
Definition
a fertilized ovum
Term
36
Definition
Term
How does the mammalian blastocyst implant itself in the endometrium?
Definition
through the action of trophoblastic enzymes
Term
What hormones helps with contraction and cilia movement to move the sperm towards the site of fertilization?
Definition
estrogen
Term
What are the two stages of growth experienced by the zygote just after fertilization?
Definition
morula, blastocyst
Term
What is the blastocoele?
Definition
the part of the blastocyste that becomes the amniotic sac
Term
What part of the blastocyste is destined to become the fetus?
Definition
the inner cell mass
Term
What is the trophoblast?
Definition
the part of the blastocyst that accomplishes implantation  and develops into fetal portions of the placenta
Term
What happens during the beginning steps in the ampula after fertilization?
Definition
  • the zygote unergoes a number of mitotic cell divisions (morula) 
  • increasing concentration of pregesterone stimulates secretion of a nutrient medium into reproductive tract lumen 
Term
How does descent of the morula into the uterus occur?
Definition
by oviductal peristaltic contractions
Term
Why does it take so long for the morula to descend into the uterus?
Definition
it allows sufficient nutrients to accumulate in the uterus 
Term
While the morula is floating in the uterus, what happens?
Definition
it becomes a blastocyst and the uterus prepares for implantation
Term
What is another name for the trophoblast?
Definition
trophectoderm 
Term
What is the function of the trophectoderm?
Definition
it accomplishes implantation, provides nutrients, and becomes the fetal part of the placenta
Term
What is the placenta?
Definition
the organ of exchange between maternal and fetal blood
Term
What is the chorion?
Definition
the trophoblastic layer from the embryo
Term
What is the allantois?
Definition
the out growth of the hindgut
Term
How many layers of tissue separate maternal and fetal blood?
Definition
6
Term
What are the maternal layers made up of?
Definition
endothelium, endometrial stromal (connective tissue), epithelium (uterine luminal)
Term
What are the fetal tissue layers made up of?
Definition
epithelium (chorionic), stromal tissue (chorioalantoic), endothelium
Term
When implantation is complete, where is the blastocyste located?
Definition
it is completely buried in the endometrium
Term
45
Definition
Term
What does the venous blood of the fetus pick up?
Definition
it picks up nutrients and oxygen and returns it to the heart
Term
What do the hormones secreted by the CL and placenta do?
Definition
 they play a critical role in maintaining pregnancy
Term
What happens to humans, mares, and sheep with regards to hormone production for pregnancy maintanence?
Definition
the placenta takes over a produces progesterone
Term
What happens in pigs, cow, goats, and rats with regards to hormone production for pregnancy maintenance?
Definition
the CL produces progesterone throughout gestation
Term
How long is the CL required in humans to maintain pregnancy?
Definition
50 days
Term
How long is the CL required in mares to maintain pregnancy?
Definition
100 days
Term
What is the function of chorionic gonadotropin?
Definition
  • it maintains the corpus luteum of pregnancy
  • stimulates secretion of testosterone by developing testes in male embryos
Term
What is the function of estrogen as a placental hormone?
Definition
  • stimulates growth of the myometrium, increasing uterine strength for parturition
  • helps prepare the mammary glands for lactation
Term
What is the function of progesterone as a placental hormone?
Definition
  • it supresses uterine contractions to provide a quiet environment for the fetus
  • promotes formation of the cervical mucus plug to prevent uterine contamination
  • helps prepare the mammary glands for lactation
Term
What is the function of relaxin as a placental hormone?
Definition
  • softens the cervix in preparartion for cervical dilation during parturition
  • loosens connective tissue between pelvic bones in preparation for parturition
Term
50
Definition
Term
51, 52
Definition
Term
What system/organ has the longest critical period during development?
Definition
the central nervous system
Term
53
Definition
Term
In what ways do maternal body systems respond to increased demand of gestation?
Definition
  • uterine enlargement (16 times by weight)
  • mammary gland
  • blood volume increase (30%)
  • respiratory activity (16%)
  • kidney output
Term
How is glucose transported across the placenta?
Definition
by facilitated diffusion by non-insulin dependent hexose transporters (GLUT 1, GLUT 3)
Term
How are amino acids transported across the placenta?
Definition
by active transport
Term
With regards to amino acids, maternal ________ is converted into _______ prior to delivery of the fetus. 
Definition
serine, glycine
Term
How are fatty acids transported across the placenta?
Definition
it varies among species
Term
What is unique about the transport of antibodies acroos the placenta in primates and rodents?
Definition
there is a substantial transfer of immunoglobulin G
Term
What is unique about ruminants, horses, and pigs with antiboy transport across the placenta?
Definition
there is no transfer of immunoglobulins
Term
What is bilirubin?
Definition
it is a waste product from heme in hemoglobin
Term
What happens to bilirubin?
Definition
it is conjugated in the liver to make it water soluble and then excreted into bile
Term
What happens to bilirubin in the fetus?
Definition
  • it can only be conjugated in small portions but the unconjugated form can be transported across the placenta and excreted by the mother
Term
How much of the glucose turnover in the ewe is removed by the fetus near term?
Definition
70%
Term
What happens in non-ruminants with ragards to carbohydrates?
Definition
there is no apparent increase in gluconeogenesis
Term
What happens in ruminants with regards to glucose?
Definition
there is increase gluconeogenesis because not enough is absorbed through the diet
Term
What happens to maternal glucose utilization?
Definition
it decreases to accomodate the increased demand by the fetus
Term
What happens to nitrogen metabolism in early pregnancy?
Definition
  • stores amino acids as maternal protein for late gestation
  • the dam retains protein in the muscle to give an increase in lean tissue of 8.5%
Term
What happens to nitrogen metabolism in late pregnancy?
Definition
  • hormonally controlled muscle protein mobilizes to meet the rapid fetal growth
  • increased efficiency in utilizing digested nitrogen: increased rate of urea recycling and increased absorption of amino acids in the digestive tract 
Term
Changes in late gestation prepare for ____________.
Definition
parturition
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