reproduction 2 Flashcards
the uterine ( ____ ) tubes ( ____ ) are not directly attached to the ovaries, but open into the ____ cavity near the ovaries with the opening surrounded by projections called ____ ; their other ends are attached to the uterus and empty into its cavity
fallopian
oviducts
abdominopelvic
fimbriae
cervix
inferior part of the uterus and opens into the vagina
functions of the ovaries
ooogenesis (during the fetal period)
maturation of the oocyte
expulsion of the mature oocyte (ovulation)
secretion of estrogen, progesterone, and inhibin
oogenesis
the division of stem cell oogonia (primitive germ cells) by numerous rounds of mitosis to produce a clone of oogonia
occurs during early fetal development
at birth, the ovaries contain ____ “eggs” and no new ones appear after birth
roughly 400 of these will be ____ during the female’s lifetime
the others ____ at some point in their development so that few if any remain by the time she reaches the age of about ____
2-4 million
ovulated
degenerate, 50
during fetal life, all the oogonia eventually develop into:
these cells then begin meiosis ____ (by replicating their DNA), but do not complete the ____
primary oocytes
I , division
at birth, all the eggs present are ____ oocytes containing ____ chromsomes, each with ____ sister chromatids, in a state of meiotic arrest
this continues until ____ and the beginning of renewed activity in the ovaries
primary, 46, 2
puberty
completion of meiosis I occurs just before the egg is ____ in a give reproductive cyle (thus, only those eggs destined for ovulation ever complete meiosis ____ )
ovulated
I
at the completion of meiosis I, each daughter cell contains ____ chromsomes (each with ____ chromatids), but one daughter cell - the ____ oocyte - receive nearly all of the cytoplasm
the other daughter cell called a ____ ____ , is small and nonfunctional
23, 2, secondary
polar body
meiosis II occurs in a ____ ____ after ____, but only if the secondary ooxyte has been ____
uterine tube, ovulation, fertilized
in meiosis II, one daughter cell, now called an ____ , recieves nearly all the cytoplasm, and the other cell, again called a ____ ____ is small and nonfunctional
as a result of meiosis II, the daughter cells each have ____ chromosomes, each with ____ chromatid
ovum, polar body
23, 1
a newly fertilized egg is called a
zygote
follicle growth:
- eggs in the ovaries exist in structures known as ____
- follicles begin as ____ follicles, each of which consists of one primordial ____ (about to become a primary oocyte) surrounded by a single layer of ____ cells
- before but mostly after birth, the primordial follicles develop
- the ____ gets larger, the ____ cells proliferate by mitosis into multiple cell layers, and the oocyte becomes separated from the inner granulosa layer by a layer of glycoprotein material called the ____ ____
- follicles
- primordial, ovum, granulosa
- oocyte, granulosa, zona pellucida
the glycoproteins (that make up the zona pellucida) play a role in binding
the sperm to the surface of the egg
granulosa cells secrete ____ and ____ and, just before ovulation, small amounts of ____
estrogen
inhibin
progesterone
small cytoplasmic processes connect the inner granulosa cells with
the oocyte and allow nutrients and chemical messengers to reach the oocyte
as the follicle continues to grow after birth, ____ cells form outside of the granulosa cells, the primary oocyte reaches full size, and the ____ , a fluid-filled space, forms in the midst of the granulosa cells as a result of the fluid they secrete
theca
antrum
some primordial follicles progress to the early antral stages during infancy and childhood; for others, this occurs during the post-pubertal female’s reproductive cycles:
at the begining of each reproductive (menstrual) cycle, ____ preantral/early antral follicles begin to develop further
10-25
although most follicles in the ovaries remain primordial, a nearly constant number of preantral and early antral follicles are also present
at all times
on about day ____ of the cycle, one follicle is “selected” as the ____ follicle, and only it continues to develop
7
dominant
____ also occurs between birth and puberty so that only 300,000 follicles remain when active reproductive life begins
99.99% of the ovarian follicles present at birth will undergo atresia rather than producing an egg that is ____
atresia
ovulated
as the antrum of the dominant follicle continues to enlarge, the ____ cell layers surrounding the egg form a mound, the ____ ____ , that projects into the antrum
granulosa
cumulus oophorous