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Repro Quiz 3 & 4 and Exam 2

Terms in this set (53)

T/F. The cells of the inner cell mass are totipotent
False
T/F. The cells of the inner cell mass are mitotic
True
T/F. The chorion is the innermost extra-embryonic membrane, enclosing the fetus in a fluid filled cavity
False
T/F. The amnion is the innermost extra-embryonic membrane, enclosing the fetus in a fluid filled cavity
True
T/F. Endometrial cups develop in pregnant mares and secrete eCG (PMSG) which has high LH-like bioactivity
False
T/F. Endometrial cups develop in pregnant mares and secrete eCG (PMSG) which has high FSH-like bioactivity
True
T/F. Cells of the mesoderm of the inner cell mass ultimately differentiate into the nervous system, skin and hair of the fetus.
False
T/F. Cells of the ectoderm of the inner cell mass ultimately differentiate into the nervous system, skin and hair of the fetus.
True
T/F. The uterus of the pig contains caruncles
False
T/F. The uterus of the ewe/cow has caruncles
True
T/F. Dogs and cats develop an epitheliochorial-type placenta, maintaining all 6 layers
False
T/F. Dogs and cats develop an endotheliochorial-type placenta
True
T/F. During embryonic development and placentation, the amnion eventually fuses with the allantois
False
T/F. During embryonic development and placentation, the chorion eventually fuses with the allantois
True
T/F. The chorion is derived from cells of the hindgut
False
T/F. The chorion is derived from cells of the triphectoderm and mesoderm
True
T/F. Due to an increase in maternal blood volume and cardiac output, increases in blood pressure during pregnancy are expected
False
T/F. After the embryo hatches from the zona pellucida, there is no further role for the trophectoderm in the establishment of pregnancy
False
T/F. After the embryo hatches from the zona pellucida, the trophectoderm forms extra embryonic membranes
True
T/F. The luteal-placental shift occurs at ~day 50 of gestation in swine
False
T/F. The luteal-placental shift doesn't occur in swine
True
T/F. All transfer across the placental interface is by simple or facilitated diffusion
False
T/F. During pregnancy, one role for estrogen is to maintain relaxation of the myometrium
False
T/F. During pregnancy, one role for progesterone is to maintain relaxation of the myometrium
True
Identify two permissive signals that can affect the timing of puberty
Photoperiod and metabolism
Puberty in the ewe lamb can occur as early as 5 to 6 months of age. A farmer had his ewes lamb last October. When and why should he expect these ewe lambs to reach puberty?
He can expect them to come into puberty in the fall because according to photoperiod, sheep are short day breeders. Photo receptors in the retina stimulate the pineal gland to produce melatonin which stimulates the hypothalamus to affect GnRH and begin puberty.
In the ewe, describe how estradiol and progesterone affect the secretion of LH. Describe this process during both the breeding season and in periods of anestrus.
In the breeding season E2 is the moderate regulator and P4 is the dominant regulator of secretion of LG. They affect pulse frequencies and the amount (height) of the spike. In anestrus they decrease but still control the secretion of some LH.
Describe the process of parturition in the ewe. Include in your answer reference to the fetus, placenta and the "mom". Include in you answer relevant hormones, signaling pathways, changes in the expression of relative enzymes, receptors, etc.
Parturition in the ewe begins with the prepatory phase. This is when the cortisol from the fetus induces an increase in E2 and a decrease in P4. Essentially the uterus begins moving the fetus towards the birth canal and lubrication for birthing ease begins. In the mom, this phase leads to an increase in PGF2a which causes luteal regression so the ewe can get pregnant again and also the P4 removes the myometrial block. Next is the expulsion phase which is when the fetus stimulates pressure sensors on the cervix stimulating a positive feedback loop. Beginning with the hypothalamus, which stimulates that post. pituitary to release oxytocin causing a rise in PGF2a which causes strong contractions. These rhythmic contractions again stimulate the pressure receptors starting the process over again. In this phase the chorioallantoic membrane and amniotic membrane rupture. The third phase is the cleaning phase where the secretory fluids and placenta are expelled.
T/F. Placentation in the mare is considered "micro-cotyledonary"
True
T/F. Primordial germ cells originate in the genital ridge
False
T/F. A male with an extra Y chromosome is expected to be of normal fertility
True
T/F. In the developing testis, sertoli cells secrete testosterone
False
T/F. In the ewe, treatment with opioid agonists or antagonists can affect the secretion of LH
False
T/F. Endometriosis is the inflammation of the uterine endometrium plus myometrium
False
T/F. A large cystic follicle on the ovary of a dairy cow can affect steroidogenesis by small (3 to 5mm) follicles on the same ovary of that cow
True
Identify the 6 potential layers that separate maternal and fetal blood
1. Fetal endothelium
2. Fetal connective tissue
3. Fetal chorionic epithelial
4. Maternal endometrial epithelium
5. Maternal connective tissue
6. Maternal endothelium
Most invasive placentation -> Least invasive placentation
Hemochorial
endotheliochorial
epitheliochorial
What is meant by spinnbarkeit?
Stretchy and sticky cervical mucus around ovulation
In the female, describe the events that lead up to the development and/or regression of the Wolffian and/or Mullein ducts. Indicate in your answer which ducts develop into the oviduct, uterus and portions of the vagina.
There is no testosterone present to regress the Mullerian ducts therefore the Mullerian ducts develop into the oviduct, uterus and portions of the vagina.
How does the sensitivity of the hypothalamus to steroid hormones change as a bull calf approaches puberty?
It decreases.
If a woman is diagnosed with polycystic ovarian syndrome (PCOS), she must meet 2 of 3 criteria. Identify these three defining criteria and indicate a major difference between cystic ovarian disease in cattle and PCOS in women
1. Cystic ovaries
2. Increased androgens
3. Ovulatory dysfunction

Cattle tend to develop large cysts where as women tend to develop several small cysts.
T/F. In the male, Wolffian ducts develop into the testis.
False
T/F. In the male, SF1 activates/induces the testis determining factor, Sry.
False
T/F. In the male, fetal leydig cells differentiate into adult leydig cells
False
T/F. During seasonal anestrus in the ewe, estradiol will decrease the pulse amplitude of LH released by the anterior pituitary
True
T/F. The secretion of serotonin by the pineal gland is the primary regulator of seasonal anestrus in the ewe
False
T/F. Puberty in the heifer calf is expected to be delayed if that animal is reared on a low plane of nutrition
True
T/F. The gonadostat hypothesis equates the changes that occur in feedback at puberty to a resetting of the hypothalamic/pituitary/gonadal axis "thermostat"
True
Leptospirosis is a bacterial disease that can affect cattle. There are multiple serovars of bacterium involved. Depending on the serovar, the disease is classified as host-adapted or nonhost-adapted. What is the difference?
Host-adapted is when there is infection from cattle to cattle. Non host-adapted is from another species to cattle.
What bacterial disease can cause pregnancy loss in cattle but has been largely eradicated from the US?
Brucellosis
Describe what is meant by metritis
Metritis is inflammation of the myometrium and endometrium
Describe what is meant by endometritis
Endometritis is inflammation of the endometrial tissue
Describe what is meant by endometriosis
Endometrium tissue that grows outside of the repro tract in the abdomen and is very painful.
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