Quiz 5 Flashcards
Definition of reproduction
The action or process of making a copy of something
Sexual interaction of gametes which produces an offspring organism with genetic characteristics derived from two parental gametes
Mammalian reproduction
Reproduction is inherently complex: interactions between —> determine the success of reproduction
Reproductive tract
Hormones
Nutrition
Genetics
Environment
HPG axis
Hypothalamus
GnRH
Anterior pituitary
LH, FSH
Gonads
Sex hormones
Regulation of gametogenesis by hypothalamic and pituitary hormones
GnRH
LH
FSH
Steroids made by the gonad form a
Negative feedback loop with the hypothalamic and pituitary hormones
Pituitary hormones also stimulate growth and differentiation of gametes
Spermatogenesis
Folliculogenesis
Follicular phase:
The female gamete develops surrounded by supporting somatic cells which produce steroid hormones under the direction of gonadotropins
Luteal phase:
After ovulation, the somatic cells differentiate into luteal cells which make progesterone
GnRH is released from
Neurons which are stimulated by other neurons
In the female hypothalamus _________ determines tonic vs. surge release of GnRH
Kisspeptin
Pulses of GnRH cause pulsatile release of
FSH and LH
LH and FSH regulate
Steroid hormone synthesis
Steroid hormone synthesis exerts
Feedback regulation of GnRH
During the follicular phase, FSH stimulates
Follicle growth which leads to increased E2 synthesis
Upon reaching threshold concentration,
E2 stimulates GnRH surge
The LH surge causes
Rupture of dominant follicle
Release of oocyte and granulosa cells
The remaining granulosa cells and Theca cells undergo differentiation into luteal cells to form a
Corpus luteum
On the luteal cell, LH binds the _____ and stimulates _____ _________
LH-R
cAMP production
cAMP alters the
Activity of enzymes that internalize cholesterol into the cell and promote its metabolism to the steroid progesterone
_____ is the main factor initiating luteolysis
PGF2alpha
PGF2alpha induces ___ ______ and increases
Cell death
Metabolism of P4
_____ is also initiated by immune cells that invade CL and activate the apoptotic pathway
Apoptosis
The corpus luteum is not responsive to PGF2alpha for __ to __ days after luteal cells form
7 to 10
PGF2alpha is initially made in the
Uterus due to increased oxytocin receptor expression
Oxytocin is synthesized in the
Hypothalamus
Oxytocin is secreted from the
Posterior pituitary
Progesterone (P4) is synthesized and secreted from the
Luteal cells
Progesterone inhibits
GnRH, FSH, and LH release from the hypothalamus and anterior pituitary
Uterine myometrium contractility
Progesterone stimulates
Uterine glandular secretions
Progesterone induces
Mammary gland differentiation
Luteolysis is inhibited by
Species-specific mechanisms upon establishment of pregnancy
Women pregnancy recognition factor
hCG
Species with no pregnancy recognition factor needed
Bitch, Queen
Myometrium contractions cause the fetus to
Descend upon the cervix
Neural signals from the myometrium travel to the
Hypothalamus - increase oxytocin secretion
Oxytocin increased
Myometrium contractility
Parturition result
Positive feedback loop until fetus and placenta are expelled
Puerperium is the
Period after parturition when the reproductive tract returns to its non pregnant condition in preparation for a a subsequent conception
Four major events during puerperium
Myometrial contractions
Endometrial repair
Resumption of ovarian cyclicity
Elimination of bacterial contamination of the reproductive tract
Post-partum reproductive tract is an ideal environment for
Bacteria l
Lochia
Uterine fluid after parturition
Causes of infection
Retained fetal membranes
Dystocia and delay in lochia expulsion
Complications of infection
Prolonged uterine involution
Prolonged puerperium
Delay in estrous cycle resumption
Delay of subsequent pregnancies
MGA and CIDRs are often used to
Synchronize heifers
POMC increaes the
ARC kisspeptin neuron activity
What inhibits ARC kisspeptin neuron activity
NPY-AgRP
Godzilla reproduces
Asexually
Why is it important to keep the CL for establishment of pregnancy?
Preventing contractions of uterus
CL produces progesterone which supports pregnancy - establishes endometrium for pregnancy
What factor normally causes CL regression in cows, sows, ewes and women? Where does this factor come from?
PGF2alpha
Comes from uterus - oxytocin tells uterus to make PGF2alpha
What factor prevents CL regression in the cow and ewe? Sow? Woman?
Cow/ewe - no oxytocin receptor —> PGF2alpha can’t be accepted and CL progresses
Sow - estrogen in uterus
Woman - hCG
What does a human pregnancy test measure? Why does this indicate that she is pregnant or not pregnant?
Measures hCG
Increased hCG means pregnant
Can you use this test to determine if another animal is pregnant? Why or why not? Do you think this would be an accurate test to determine if Godzilla had reproduced? Why or why not?
Can’t use this test for another animal, h=human and animals don’t have hCG
Not accurate for Godzilla because Godzilla lays eggs, no hormone
Why is there NO maternal recognition of pregnancy factor produced by the dog or cat?
Cats are copulative
Dogs have long cycles
Do you think Godzilla makes a maternal recognition of pregnancy factor? Does Godzilla make a CL? Is P4 production important for establishment of pregnancy in this radioactive lizard?
No
Do you think scientist Nick is interpreting the results of Godzilla’s pregnancy test correctly?
No
How does insulin affect the estrous cycle?
Stimulates POMC which stimulates kisspeptin which stimulates GnRH
How does lepton affect estrous cycle?
Too much/not enough throw off cycle
High energy use by normal body can
Reduce cyclicity
