Final: Female Repro Flashcards
Define Oogenesis:
is a meiotic process that begins during embryonic development and culinates in the formation of a single haploid oocyte and “three” polar bodies.
Where do the primordial germ cells develop from?
from the germinal epithelium of the indifferent gonad early in embryonic development, migrate into the future ovaries to become OOGONIA
Oogonia:
are surrounded by a single layer of nongerminal granulosa cells
what is a primary follicle?
the oogonium plus granulosa cells
The primary oocyte (ovum) becomes arrested during?
the diplotene state of prophase I.
- all primary oocytes are arrested during the diplotene state of meiosis I during embryonic development
What happens to most of the primary oocytes before birth?
they become atretic (degenerate)
initially there are ~7 million oogonia cells, after birth how many are there?
500,000
when does one of the primary oocytes complete the first stage of meiosis?
beginning at puberty
once the primary oocyte completes the first stage of meiosis it becomes?
a secondary oocyte + polar body
after a seondary oocyte completes the second half of meiosis it becomes?
ootid + polar body
where does fertilization occur?
at the second metaphase stage of oogenesis
-meiosis is not complete unless fertilization occurs.
What are the ovarian phases of the menstral cycle?
days 5-14: follicular growth
day 14: ovulation
Days 14-23 devel. of corpusluteum
days 24-28: regression of corpus lutem
What are the uterine phase of the menstral cycle?
Days 1-5: menstration
Days 4-14: proliferation
Days: 14-28 secretion
hypothalamic releasing hormone: gonadotropin releasing hormone (GnRH)
it is secreted in short pules averaging once every 90 minutes, as occurs in males.
what are the two anterior pituitary sex hormones
FSH, LH
What are the two ovarian hormones
estrogen and progesteron
what hormones have almost no secretion throughout childhood and are small glycoproteins with MW of about 30,000?
anterior pituitary sex hormones: FSH, LH
what do FSH and LH combine wtih?
highly specific receptors in ovarian target cell membranes
Signal transduction from the combination of what hormones involving the cAMP second messenger system leads to the formation of protein kinase and multiple phosphorylations.
FSH, LH
what are primordial follicles surrounded by?
single layers of granulosa cells
what do granulosa cells do throughout childhood?
provide nourishment for the ovum.
and secrete oocyte maturation-inhibiting factor, keeping ovum suspended in its primordial state.
The duration of the menstrual cycle averages 28 days….what is the range
20-45 days
Theca interna:
cells become epithelioid and develop the ability to secrete estrogen and progesteron
Theca externa
will become the protective capsule of the developing follicle
Granulosa cells
- secrete a follicular fluid containing a high concentration of estrogen.
- This cause an antrum to appear.
This is referred to as spindle-shaped cells aroudn follicles from multiple layers around each follicle
Theca
What is the first state of follicular growth?
moderate enlargement of the ovum itself, which increases in diameter 2-3x
after enlargement of the ovum, growth of additional layers of granulosa cells in some of the follicles leads to :
secondary follicles
When do concentrations of both FSH and LH increase slightly?
during the first few days of menstrual cycle.
-FSH slightly greater than LH
What does an increase in both FSH and LH lead to?
growth of multiple follicles
