Repro Final Flashcards
In 1677, Anthony van Leeuwenhoek described spermatozoa. What was instrumental for this to occur?
Microscope
Name the tubule/ductile that transports spermatozoa from the testis into the epididymis.
Efferent ductiles
Indicate 3 roles for epididymis.
Nourish
Allow sperm to mature
Storage depot
Indicate the hormones secreted and regulatory direction in the feedback loop.
Hypothalamus GnRH(+) Anterior Pituitary LH(+) FSH(+) Leydig cells and Sertoli cells
Define/describe spermatogenic cycle and spermatogenic wave.
Spermatogenic cycle: Measure of time at a certain point of the cycle
Spermatogenic wave: Measure of distance of the tubule from round spermatid to round spermatid
At the time of ejaculation, have spermatozoa undergone a.) meiosis and b.) capacitation ?
Spermatozoa has undergone meiosis, but not capacitation.
3 steps of spermatogenesis:
- ) Proliferation
- ) Meiosis
- ) Differentiation
If you castrate a male, would you expect luteinizing hormone (LH) to increase or decrease. Why?
Increase! You remove the leydig and sertoli cells, so therefore you remove the (-) feedback and the body doesn’t stop making.
What is the role for the golgi apparatus within the differentiating spermatid?
The GA ends up folding itself over the nucleus which eventually leads to the acrosomal cap for the sperm.
Contractions of the uterus are important to facilitate movement of male germ cells through the female reproductive tract. Is the oviduct also a contractile organ?
Yes!
Explain the acrosome reaction.
Acrosin is involved. The acrosome reaction (when induced) allows the sperm to pass through the acrosome and digest into the zona pellucida of the oocyte for eventual DNA dispersal.
Name the 2 blocks to polyspermy that are induced by the cortical reaction.
The zona pellucida block - prevents sperm from reentering
The vitelline block - keeps selected sperm from exiting
Are the cells of the 8-cell embryo considered totipotent? What does this mean?
Yes.
Totipotent = have all the DNA required to make the whole animal
What is meant by the “cleavage” of the early embryo?
From 2-16 cells in mitotic division, there is a “cleavage”. At this stage, cells are considered totipotent.
T or F: A primordial follicle contains a primary oocyte surrounded by the zona pellucida and a single layer of cuboidal granulosa cells.
False.
No ZP at primary and pregranulosa cells are flattened.
At what stage of meiosis would the oocyte of a small antral follicle be arrested in?
Diplotene of prophase I
How did scientists determine that pre-antral follicular development was NOT dependent on gonadotropins?
Removed blood supply.
T or F: At the time of recruitment, granulosa cells express receptors for LH and theca cells express receptors for FSH.
False.
Theca: LH-R (doesn’t respond to FSH)
Granulosa: Both (after selection)
Name the hormone that causes the recruitment of a cohort of follicles.
Follicle stimulating hormone (FSH)
T or F: In a dominant follicle, the theca interna is steroidogenic and produces estradiol,
False.
Granulosa cells produce estradiol.
Theca interna: androstendione
Steroid hormones are derived from…
Cholesterol
Steroidogenic Acute Regulatory Protein (STAR protein) is important for the…
Cholesterol to be converted to androstendione in the theca interna.
Which is converted to estradiol by the granulosa cell.
Name the hormone that induces regression of the corpus luteum and identify where it is produced.
Prostaglandin F2A secreted in the uterus
3 extra-embryonic memrbanes.
- ) Amnion - surrounds embryo
- ) Allantois - vascular; attaches with chorion
- ) Chorion - outer
Identify the 6 potential layers used to classify the maternal/fetal barrie.
- ) Fetal endothelium
- ) Fetal connective tissue
- ) Fetal chorionic epithelium
- ) Maternal endometrial epithelium
- ) Maternal connective tissue
- ) Maternal endothelium
T or F: In the ewe, placentation can be considered endotheliochorial.
False.
Epithelialchorial
What is the role for eCG during early pregnancy?
Acts as FSH, follicular development, luteal, and more CL for progesterone
Identify the tissue responsible for production of eCG and the species of animal producing it.
Equine (horse) endometrial cups
T or F: During a normal pregnancy, maternal blood pressure is significantly increased.
False
T or F: During pregnancy, the ability of maternal blood to coagulate decreases.
False
Identify the two components of a placentome (ewe or cow) and indicate which component is of fetal origin and which is of maternal origin.
Fetal cotelydon
Maternal caruncle
T or F: In the ewe, parturition occurs in response to activation of the maternal hypothalamic/pituitary/gonadal axis.
False
Humans - placental
At parturition in the ewe, what causes the release of oxytocin from the maternal posterior pituitary?
Pressure sensors in the cervix
Puberty in the ewe lamb can occur as early as 5-6 months of age. Farmer Bob in southern KY had his ewes lamb last October. When should he expect these ewe lambs to reach puberty?
12-13 months later or around the October because they are seasonal breeders that respond to day length.
What gland produces the hormone melatonin?
Pineal gland
Farmer Bob’s cousin Billy decided to raise swine. He purchase 20 infant gilts and one mature boar to start his operation. They were all housed in close proximity to one another. Puberty typically occurs in gilts around 28 weeks of age. At what age should Billy expect his 20 gilts to reach puberty?
24 weeks due to the presense of the mature boar