Test 1 Flashcards
Maternal Recognition of Sow
In the sow, maternal recognition of pregnancy begins 11-12 days into the cycle, with the signal being estradiol. Estradiol redirects PGF2a into the lumen of the uterus and away from the ovaries. If this did NOT happen, PGF2a would rich the ovaries and regress to the corpus luteum (which is vital to maintain pregnancy).
In females, what stage of meiosis is arrested?
Diplotene of Prophase I
Release of the mature spermatozoa into the lumen of the seminiferous tubule
Spermiation
Sperm are made every ____ normally.
2 weeks
Function of the mitochondrial sheath
-Cell that produces the energy
ZP3 is…
-A receptor to sperm
Luteal Regression of Ewe
PGF2a induces luteal regression and it is produced in the uterus. It reaches the ovary directly by way of the ovarian artery. Allows PGF2a to get directly to the CL. If PGF2a reaches the lungs it is unusable.
How does P4 affect the endometrium and myometrium?
Endometrium: P4 increases secretions/ nourish embryo
Myometrium: P4 causes relaxation of muscles; allows stretching
Lutenization
Opposite of Luteal regression. Induced by LH/FSH surge; follicular cells -> lute am cells; P4 is made (transformation of granulosa and theca cells)
Before fertilization, the stage of meiosis that the oocyte is arrested in is….
Metaphase 2
What hormone does CIDR release?
P4 to prevent ovulation
Synchronization of 50 heifers
- ) Want to control the ovary -> Corpus Luteum
- ) Will place CIDR to act as the CL for 7 days (Uses P4 to prevent ovulation)
- ) Then remove CIDR and give shot of PGF2a to kill any CL that were actually present (Should get 2/3 on the same cycle)
- ) Give another shot of PGF2a 11 days later to kill any remaining CL present. (should get all on the same cycle)
- ) Use GnRH 36 hours later to induce the LH surge and begin ovulation.
Capacitation
Physiological changes that occur to sperm in the female reproductive tract (vagina). Has to occur in order for fertilization to take place. The physiological change is exposure of the egg-binding sites.
Where does capacitation occur?
Vagina
Total hysterectomy in ewe during the mid luteal phase of the estrous cycle, (a) how long is CL maintained and (b) why?
A) length of gestation (about 9 months)
B) Because the uterus is not able to produce and release hormones, like PGF2a, to control CL development or regression.
No negative feedback to stop the secretion of P4.
Fertilization occurs in the uterus? T/F
False, oviduct
FSH induces recruitment of a cohort of follicles? T/F
True
What is the proteolytic enzyme released from acrosome of spermatozoa?
Acrosin –> helps break down acrosome
What is Pampiniform Plexus?
Large system of veins that surrounds the testicular artery. Functions to regulate temperature in testes (cooler) and to allow high amounts of testosterone to be concentrated in the testes
Explain Acrosin (Acrosomal Reaction)
When induced, the acrosome reaction allows sperm to pass through the acrosome and digest into the ZP of the oocyte for eventual DNA Dispersal.
The outer acrosomal membrane and plasma membrane fuse together and start to dissolve holes in the zona pellucid of the oocyte. The sperm then gets locked into the perivitella space of the oocyte.
2 blocks to block polyspermy (induced by the cortical reaction
1) ZP Block- Prevents a second sperm from entering
2) Keeps the selected sperm from exiting
Granulosa cells produce
Estradiol
Theca Interna produce
Androstendione
Are the cells of the 8-cell embryo considered totipotent and what does totipotent mean?
Yes, totipotent means they have the ability to make anything.
*Have all of the DNA required to make the whole animal
What is meant by cleavage of the early embryo?
Mitotic division
A primordial follicle contains a primary oocyte surrounded by the zona pellucida and a single layer of cuboidal granulosa cells? T/F
False.
No ZP at primary and pre-granulosa cells are flattened
How did scientists determine that pre-antral follicular development was not dependent on gonadotropins?
- Removed the blood supply
- Gonadotropins to stop GnRH to reach -anterior pituitary, removed LH
In a dominant follicle, the theca intern is steroidogenic and produces estridiol. T/F
- False
- Theca interna = androstendione
- Granulosa cells produce estradiol
Steroid hormones are derived from _______
Cholesterol
STAR is important for the
- Cholesterol to be converted to androstendione which is converted to estradiol by the granulosa cells.
- In the theca interna
Name the hormone that induces regression of the corpus luteum and identify where it is produced
PGF2a secreted in the uterus
What is the major component of cumulus cells?
Sperm head contains…
Hyaluronic acid
Sperm head: hyaluronidase
