Ovulation & implantation week one Flashcards
The ovarian cycle starts at puberty. What hormones controls this cycle ?
GnRH
Secreted from the hypothalamus
GnRH acts on the anterior pituitary which secretes ____ & ___ which stimulate and control cyclic changes in the ovary.
FSH & LH
At the beginning of each ovarian cycle, 15-20 primary-stage (preantral) follicules are stimulated to grow under the influence of FSH. How many succeed ?
1
Since only one follicle reaches full maturity per cycle what do other follicles become ?
They degenerate and become artretic ands are replaced by corpus atreticum.
FSH also stimulates the maturation of follicular (granulosa cells) around the oocyte. In cooperation, tehca interna & granulosa cells produces _____.
Estrogens
What is the role of estrogen in preparation for ovulation ?
It causes the uterine endometrium to enter the proliferative phase.
It causes thinning of the cervical mucus to allow passage of sperms.
It causes the anterior lobe of the pituitary gland to secrete LH
At midcycle, there is a surge in ____ (hormone) . This causes oocytes to complete meiosis 1 and initiate meiosis 2. This surge also stimulates the production of progesterone by follicular stromal cells. In the meantime, the surface of the ovary begins to buldge locally and forms the ____. Finally, it causes follicular rupture and ovulation of the oocyte together with its surrounding granulosa cells at about 14 days of a 28 day menstrual cycle.
LH
Stigma
After ovulation, the remaining granulosa cells will become temporary endocrine glands called _______. It secretes the progesterone for the continuous preparation of the endometrium for implantation. If fertilization does not occur, the corpus luteum reaches maximum development after 9 days after ovulation and subsequently, forms a mass of fibrotic scar tissue, the _______. Simultaneously, progesterone production decreases, precipitating menstrual bleeding.
Corpus luteum
Corpus albicans
If the oocyte is fertilized, the corpus luteum continues to grow and forms the _______. It continues to secrete progesterone until the end of the 1st month.
Corpus luteum of pregnancy
In regards to prepation for fertilization
The ovum which is surrounded by the _______ cells and the zona pellucida is located in the ampulla of the fallopian tube and ready to meet _______ sperm to be fertilized.
Corona radiate
Capacitated
What is capacitation ?
A process during which the glycoprotein coat and seminal plasma protein are removed from the plasma membrane of the acrosomal region of the spermatozoa.
Only capacitated sperms can pass through the corona radiata and undergo acrosomal reaction.
What is the acrosomal reaction ?
In normal conditions, where does the fertilization occur in the fallopian tube ?
What are the 3 phases of fertilization
What is the end result of fertilization ?
Diploid …………..
What prevents the blastocyst from implantation ?
Zona pellucida membrane
A blastocyst consists of inner cell mass (embryoblast) and outer cell mass (throphoblast). Which layer is directly in contact with the endometrium so that implantation can occur ?
throphoblast
The side of the blastocyst to which the inner cell mass is attached is called embryonic/animal pole. What is the opposite side called ?
Abembryonic
Name 2 abnormal types of implantation:
Ectopic pregnancy
Placenta previa
The ovarian cycle is associated with surges of what hormones from the pituitary ?
What about the uterine cycle
LH & FSH
Estrogen & progesterone
What are the 3 phases of menstrual cycle?
Menstrual
Proliferative
Luteal
If fertilization occurs, what happens with the luteal phase ?
What if it does not occur ?
it continues
it stops, and the menses happen
Briefly describe the 3 phases of menstrual cycle.
Menstrual
Proliferative
Luteal
Transvaginal ovum retrieval and in vitro fertilization are types of :
Assisted reproduction
