Female Reproduction System Flashcards
what does the female reproductive system consist of?
- paired ovaries
- paired oviducts
- the uterus
- the cervix
- the vagina
- external genitalia
- paired mammary glands
what type of epithelium covers the ovaries?
simple cuboidal epithelium (germinal epithelium)
what is germinal epithelium?
germinal epithelium is found in the ovaries and is of simple cuboidal epithelium
what lies deep to germinal epithelium of the ovaries?
deep the the germinal epithelium lies a dense, irregular collagenous connective tissue capsule calle dthe tunica albuginea
what is the tunica albuginea found in the ovaries?
tunica albuginea is a dense, irregular collagenous connective tissue capsule that lies deep the the simple cuboidal (germinal) epithelium of the ovaries.
what is each ovary divided into?
into a cortex and medulla - not sharply delineated
what does the ovarian cortex consist of?
- ovarian follicles in various stages of development
- a connective tissue stroma
in progression, what are the ovarian follicles?
ovarian follicles:
- Primordial follicles
- Primary follicles:
- unilaminar primary follicle
- multilaminar primary follicle - Secondary follicle
- Graafian (mature) follicle
after ovulation, what is formed from the remnants of the graafian follicle?
the corpus hemorrhagicus
what are primordial follicles composed of?
primordial follicles are composed of a primary oocyte enveloped by a single layer of flat follicular cells
what is a primary oocyte?
a primary oocyte had become arrested in prophase of meiosis 1 by paracrine factors produced by the follicular cells during foetal life and remain in theis stage until ovulation
what is the structure of a primary oocyte?
a primary oocyte contains a prominen, acentric, vesicular-appearing nucleus (germinal vesicle) possessing a single nucleolus.
they have many Golgi complexes, mitochondria, profiles of RER and well-developed annulate lamellae
what phase of meiosis is the primary oocyte arrested in foetal life?
prophase of meiosis 1
are primary follicles dependent of FSH for their development?
no, they are not dependent on Follicular-stimulating hormone (FSH)
what do primary follicles possess?
primary follicles possess an amporphous layer (zona pellucida) surrounding and produced by the primary oocyte; a basal lamina is present at the interface of follicular cells with the stroma.
what is the zona pellucida?
zona pellucida is an amorphous layer surrounding and produced by the primary oocyte.
what are unilaminar primary follicles?
unilaminar primary follicles develop from primordial follicles in the ovaries.
they are composed of a single layer of cuboidal follicular cells surrounding the primary oocyte
what are multilaminar primary follicles?
multilaminar primary follicles develop from unilaminar primary follicles by proliferation of follicular cells
they consist of several layers of follicular cells; now known as granulosa cells.
they are circumscribed by two layers of stromal cells:
- inner cellular layer (theca interna) - outer fibrous layer (theca externa)
why do follicular cells of unilaminar primary follicles?
follicular cells of unilaminar primary follicles proliferate because of activin, a product of the primary oocyte.
proliferation leads to the formation of multilaminar primary follicles.
what surrounds multilaminar primary follicles?
they are circumscribed by two layers of stromal cells:
- inner cellular layer (theca interna) - outer fibrous layer (theca externa)
what do cells of the theca interna manufacture?
and what is its fate?
androstenedione (male sex hormone)
androstendione penetrates the basal lamina, that separates the granulosa cells from the theca interna, enters granulosa cells where the aromatase converts it into estradiol (female sex hormone)
how are secondary follicles established?
secondary (antral) follicles are established when fluid begins to accumulate in the spaces between granulosa cells. the fluid-filled spaces will begin to coalesce, eventually to form a single large cavity called an antrum
what are secondary follicle dependent on for their development?
FSH
are secondary follicles dependent on FSH?
yes
how is a dominant Graafian follicle established??
Graafian follicles are mature follicles.
usually only one dominant Graffian follicle among the other developing follicles will ovulate.
it is FSH independent and produces inhibin that shuts off FSH production in the basophils of the anterior pituitary and therefore stops the development of other follicles (secondary and other Graafian follicles)
describe the dominant Graafian follicle…
the dominant Graafian follicle is ~2.5cm in diameter and is evident as a large bulge on the surface of the ovary
the primary oocyte is positioned off centre on a small mound of granulosa cells (cumulus oophorus) that projects into the liquor folliculi (antrum).
granulosa cells surround the zona pellucida; those contacting the zona pellucida are known as corona radiata. other granulosa cells line the antrum forming the membrana granulosa.
what does the theca interna of Graafian follicles manufacture?
androgens;
they are tranferred to granulosa cells and converted into estrogens
how does ovulation of the dominant Graafian follicle occur?
ovulation occurs in response to the LH surge. the secondary oocyte and its corona radiata cells leave the ruptured follicle at the ovarian surface to enter the fimbriated end of the oviduct
- an LH surge trigger the primary oocyte to finish the first meiotic division, forming the second oocyte.
second meiotic division is blocked at metaphase
how is the secondary oocyte established?
an LH surge from the pituitary gland, along with the local factor, meiosis-inducing substance, triggers the primary oocyte to complete its first meiotic division just prior to ovulation, forming a secondary oocyte and the first polar body.
the second meiotic division is triggered by the presence of local meiosis-inducing factors but is blocked at metaphase.
how is the second meiotic division of a secondary oocyte triggered?
where in the second meiotic division is it blocked?
the second meiotic division of a secondary oocyte is triggered by the presence of local meiosis-inducinf factors but is blocked at metaphase.