Animal Science 300
Lecture Quiz #2
March 14, 2001
Name___________________
I. Label the
endocrine profiles, then bracket and label the stages of the estrous cycle on
the graph below. (12)
II. Complete the
following with the most appropriate word or phrase. (10)
1.
Cell type(s) which differentiate into luteal cells under the
influence of LH.
2.
Vascular mechanism by which PGF2a
is transported from the site of synthesis to the corpus luteum.
3.
Steroid hormone which inhibits myometrial contraction.
4.
Secretory phase of the menstrual cycle.
5.
Protein hormone which increases in antral follicles following selection.
III. If cows on days 3, 9, 16, and 0 are treated at the same time with
PGF2a,
which animals (theoretically) will have synchronized estrous cycles following
the single injection treatment? (3)
What stage of the estrous cycle will the synchronized animals be in
24-48 hours after treatment?
How is the PGF2a
administered?
IV. T/F. Answer T for true
and F for false. (10)
______1. Late
diestrus is characterized by an increase in oxytocin release from the corpus
luteum.
______2. Melatonin
secretion by the pineal gland is negatively correlated with GnRH release in
sheep.
______3. Follicular
waves occur throughout the estrous cycle but ovulation is inhibited when
circulating progesterone levels are high.
______4. Most
antral follicles which achieve dominance eventually undergo atresia.
______5. Stigma
formation in the Graafian follicle is facilitated by collagenase from the theca
interna.
IV. Check (Ö)
the following events which result directly or indirectly from the LH surge: (10)
______1. Cumulus
expansion and disruption of cumulus-oocyte junctional complexes.
______2.
Progression of the oocyte through Meiosis I and into Meiosis II.
______3. A peak in
estradiol production by the Graafian follicle.
______4. Stigma
formation and follicular rupture.
______5. Episodic
release of PGF2a.