Female Reproduction System Flashcards
(75 cards)
1
Q
what does the female reproductive system consist of?
A
- paired ovaries
- paired oviducts
- the uterus
- the cervix
- the vagina
- external genitalia
- paired mammary glands
2
Q
what type of epithelium covers the ovaries?
A
simple cuboidal epithelium (germinal epithelium)
3
Q
what is germinal epithelium?
A
germinal epithelium is found in the ovaries and is of simple cuboidal epithelium
4
Q
what lies deep to germinal epithelium of the ovaries?
A
deep the the germinal epithelium lies a dense, irregular collagenous connective tissue capsule calle dthe tunica albuginea
5
Q
what is the tunica albuginea found in the ovaries?
A
tunica albuginea is a dense, irregular collagenous connective tissue capsule that lies deep the the simple cuboidal (germinal) epithelium of the ovaries.
6
Q
what is each ovary divided into?
A
into a cortex and medulla - not sharply delineated
7
Q
what does the ovarian cortex consist of?
A
- ovarian follicles in various stages of development
- a connective tissue stroma
8
Q
in progression, what are the ovarian follicles?
A
ovarian follicles:
- Primordial follicles
- Primary follicles:
- unilaminar primary follicle
- multilaminar primary follicle - Secondary follicle
- Graafian (mature) follicle
9
Q
after ovulation, what is formed from the remnants of the graafian follicle?
A
the corpus hemorrhagicus
10
Q
what are primordial follicles composed of?
A
primordial follicles are composed of a primary oocyte enveloped by a single layer of flat follicular cells
11
Q
what is a primary oocyte?
A
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
12
Q
what is the structure of a primary oocyte?
A
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
13
Q
what phase of meiosis is the primary oocyte arrested in foetal life?
A
prophase of meiosis 1
14
Q
are primary follicles dependent of FSH for their development?
A
no, they are not dependent on Follicular-stimulating hormone (FSH)
15
Q
what do primary follicles possess?
A
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.
16
Q
what is the zona pellucida?
A
zona pellucida is an amorphous layer surrounding and produced by the primary oocyte.
17
Q
what are unilaminar primary follicles?
A
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
18
Q
what are multilaminar primary follicles?
A
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)
19
Q
why do follicular cells of unilaminar primary follicles?
A
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.
20
Q
what surrounds multilaminar primary follicles?
A
they are circumscribed by two layers of stromal cells:
- inner cellular layer (theca interna) - outer fibrous layer (theca externa)
21
Q
what do cells of the theca interna manufacture?
and what is its fate?
A
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)
22
Q
how are secondary follicles established?
A
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
23
Q
what are secondary follicle dependent on for their development?
A
FSH
24
Q
are secondary follicles dependent on FSH?
A
yes
25
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)
26
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.
27
what does the theca interna of Graafian follicles manufacture?
androgens;
| they are tranferred to granulosa cells and converted into estrogens
28
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
29
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.
30
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.
31
what is the corpus hemorrhagicus?
the corpus hemorrhagicus is formed from the remnants of the Graafian follicle and derives the corpus luteum
32
what is the corpus luteum composed of?
| what is it dependent upon?
the corpus luteum is formed from the corpus hemorrhagicus.
it is composed of granulosa lutein cells and theca lutein cells
it is a highly vascularised temporary endocrine gland and its formation is dependent upon LH.
33
what are granulosa lutein cells?
| - derived
granulosa lutein cells are found in the corpus luteum.
granulosa lutein cells are large (30um in diameter), pale cells that possess an abundance of SER, RER, many mitochondria, a well-developed Golgi complex and lipid droplets.
they are derived from cels of the membrana granulosa
34
what is the function of granulosa lutein cells?
granulosa lutein cells manufacture most of the body's progesterone and convert androgens formed by the theca lutein cells into estrogens
35
what are theca lutein cells?
- derived
- function
theca lutein cells are small (15um in diameter) cells are concentrated mainly along the periphery of the corpus luteum
they are derived from cells of the theca interna
theca lutein cells manufacture progesterone and androgens and small amounts of estrogen.
36
how is the corpus albicans established?
corpus albicans is the remnant of the degenerated corpus luteum
its formation is due to hypoxic conditions present in the corpus luteum as fibroblasts manufacture an overabundance of collagen.
the fibrotic event elicits the arrival of T cells that release interferon-y, a chemoattractant for macrophages. these cells release tumor necrosis factor a, a cytokine that drives both granulosa lutein and theca lutein cells into apoptosis.
as the cell death and fibrosis progresses, the corpus albicans contracts and becomes a small scar on the surface of the ovary.
37
what are atretic follicles?
atretic follicles are follicles that are undergoing degeneration.
they are commonly present in the ovary; after a dominant graafian follicle ovulates, the remaining graafian and secondary follicles degenerate.
they often show pyknotic changes in the nuclei of the granulosa cells and other degenerative changes
38
what does the ovarian medulla contain?
the ovarian medulla contains large blood vessels, lymphatic vessels and nerve fibres in a loose connective tissue stroma. they also possess a small number of estrogen-secreting interstitial cells and a few androgen-secreting hilus cells.
39
what does the primary oocyte of unilaminar primary follicles secrete?
what does the secretion facilitate?
activin
| facilitates the proliferation of granulosa cells
40
what causes the release of FSH and LH?
luteinising hormone-releasing hormone (LHRH) (GnRH) from the hypothalmus causes the release of FSH and LH from the pars distalis of the pituitary gland
41
what does FSH stimulate?
FSH stimulates the growth and development of secondary follicles and the appearance of LH receptors on the granulosa cell plasmalemma.
42
what is the regulation of FSH and LH influenced by? (3)
1. theca interna cells manufacture androgens, which are converted to estrogens by granulosa cells
2. granulosa cells also secrete inhinin, follistatin, and activin, all of which regulate FSH secretion
3. by ~day 14 f the menstrual cycle, estrogen bllod levels are sufficiently high to facilitate a sudden, brief surge of LH
43
what does the surge of LH on ~day 14 of the menstrual cycle do?
1. triggers the primary oocyte of the dominant Graafian follicle to complete meiosis 1 and to enter meiosis 2 (arrested at metaphase)
2. the dominant Graafian follicle is no longer FSH dependent, and it releases inhibin to shut off FSH release by the basophils of the anterior pituitary, causing atresia of all developing FSH-dependent follicles.
3. LH surge initiates ovulation of the sencondary oocyte from the Graafian follicle
4. LH surge promotes formation of the corpus luteum.
44
what hormones does the corpus luteum produce?
1. progesterone
2. estrogen
3. relaxin
45
what does the release of progesterone from the corpus luteum do?
progesterone is the major hormone secreted from the corpus luteum. it inhibits the release of LH by suppressing the release of LHRH but promotes development of uterine endometrium
46
what does the release of estrogen from the corpus luteum do?
estrogen inhibits the release of FSH by suppressing the release of LHRH (GnRH)
47
in the event of pregnancy, what produces hunman chorionic gonadotropin (hCG)? what does it do?
hCG is produced and released by the syncytiotrophoblast of the developing placenta.
hCG maintains the corpus luteum of pregnancy for about 3 months until the placenta takes over the production of luteal hormones (progesterone, estrogen and relaxin)
48
in the absence of pregnancy, what happens to the corpus luteum and how is the menstrual cycle reinitiated?
the corpus luteum begins to atrophy when neither LH nor hCG is present.
the lack of estrogen and progesterone also triggers the release of FSH from the pituitary, thus reinitiating the menstrual cycle.
49
what are the regions of each oviduct?
1. the infundibulum (with fimbriated end)
2. the ampulla (most common site of fertilisation)
3. the isthmus
4. the intramural portion (transverses the wall of the uterus
50
what does the wall of each oviduct contain?
1. mucosa
2. muscularis
3. serosa
51
what does the mucosa of each oviduct contain?
the oviduct mucosa is made up of the epithelium and the lamina propria.
the mucosa has extensive longitudinal folds in the infundibulum, that progressively decreases in the remaining 3 regions.
52
what type of epithelium is found in the oviducts?
| - what cell types does it consist of?
the oviduct is of simple columnar epithelium
| the epithelium consists of peg cells and ciliated cells.
53
what are peg cells?
peg cells are found in the epithelium of each oviducts.
they secrete a nutrient -rich medium that nourishes the spermatozoa, as well as cytpkines that aid in the capitation of spermatozoa
their cytoplasm contains abundant RER, a well-developed golgi complex and many apical electron-dense secretory granules.
54
what is the muscularis of each oviduct composed of?
| - what is its function?
the muscularis of an oviduct id composed of an ill-defined inner circular and an outer longitudinal layer of smooth muscle
the smooth muscle contracts rhythmically assisting in the moving the embryo towards the uterus.
55
what are the regions of the uterus?
- fundus
- body (corpus)
- cervix
56
what composes the uterine wall?
1. endometrium
2. myometrium
3. adventitia
57
what is the endometrium?
- epithelium
- stroma
the endometrium is composed of an epithelial lining and a gland-rich connective tissue stroma. it undergoes hormone-modulated cyclic alterations during the menstrual cycle.
the endometrium is lined by a simple columnar epitheliam containing secretory and ciliated cells.
the endometrium stroma resembles mesenchymal connective tissue, with stellate cells and an abundance of reticular fibres. macrophages and leukocytes are also present. the stroma houses simple tubular glands of the endometrium.
there are two layers of the endometrium
58
what are the two layers of the endometrium?
1. functional later (functionalis) - this superficial layer of the endometrium that is sloughed and reestablished monthly as a result of hormonal changes during the menstrual cycle.
2. basal layer (basalis) - is the deepest layer of the endometrium that is preserved during menstruation. it has endometrial glands, which have basal cells that provide a source for reepithelialisation of the endometrium after the functional layer is shed
59
what are the two types of arteries that supply the endometrium?
two types of arteries derived from vessels in the stratum vasculare of the myometrium:
1. coiled arteries - extend into the functionalis and undergo pronounced changes during various stages of the menstrual cycle
2. straight arteries - do not undergo cyclic changes and terminate in the basalis
60
what is the myometrium composed of?
the myometrium is the thick smooth muscle tunic of the uterus.
the myometrium is composed of inner and outer longitudinal layers and a think middle circular layer. the circular layer is richly vascularised and is often referred to as the stratum vasculare.
61
what are the phases of the menstrual cycle?
- when does it start?
- how long does each phase last?
the menstrual cycle begins on the day menstrual bleeding appears:
1. menstrual phase (days 1-4)
2. proliferation phase (days 4-14)
3. secretory (luteal) phase (days 15-28)
62
what does the menstrual phase of the menstrual cycle involve?
- how is it triggered?
the menstrual phase is characterised by a hemorrhagic discharge (menses) of the functional layer of the endometrium
the menstrual phase is triggered by spasms of contraction and relaxation of the coiled arteries (caused by low levels of progesterone and estrogen).
- long term (2-3 days) vasocontriction os these arteries causes ischemia and then necrosis
- vasocontriction is followed by a sudden, intermittent vasodilation of the coiled arteries, whcih ruptures their walls, flooding the stroma with blood, detaching the functional layer and dislodging the nectroic tissue.
63
why doesn't the basal layer of the endometrium sloughed during the menstrual phase of the menstrual cycle?
the basal layer is supplied by straight vessels that do not undergo prolonged vasoconstriction, it is not sloughed and does not become necrotic.
64
what does the proliferation phase of the menstrual cycle involve?
the proliferation phase of the menstrual cycle involves the renewal of the entire functional layer, including repair of glands, connective tissue and vascular elements.
- epithelium that lines the luminal surface of the uterus is renewed by mitotic division of cells remaining in the uterine glands of the basal layer
- glands are straight and lined by a simple columnar epithelium
- stromal cells divide and accumulate glycogen and enlarge
- coiled arteries extend 2/3 into the endometrium
65
what does the secretory (luteal) phase of the menstrual cycle involve?
the secretory phase begins shortly after ovulation and is characterised by a thickening of the endometrium, resulting from edema and secretionbu the endometrial glands
- glands become coiled; their lumen filled with a secretion of glycoprotein material; and their cells accumulate large amounts of glycogen, in the basal aspect of their cytoplasm
- coiled arteries become not only more highly coiled ut also longer, extending into the superficial aspects of the functional layer.
66
what is the wall of the cervix composed of?
the cervical wall is composed mainly of a dense collagenous connective tissue interspersed with numerous elastic fibres and a few smooth muscle cells.
67
what type of epithelium covers the cervix?
the cervix had simple columnar (mucus-secreting) epithelium except for the inferior portion (continuous with the lining of the vagina), which is covered by stratified squamous nonkeratinised epithelium
68
what do the glands of the cervix do?
the cervix does not participate in menstruation, but its secretions change during various stages of teh menstrual cycle.
branched cervical glands secrete a serous fluid near the time of ovulation that facilitates the entry of spermatozoa into the uterine lumen.
during pregnancy, cervical glands produce a thick, viscous secretion that hinders the entry of spermatozoa (and microorganisms) into the uterus.
69
where does fertilisation usually occur?
within the ampulla of the oviduct
70
what does the process of fertilisation involve?
fertilisation occurs when a spermatozoon penetrates the corona radiata and the zona pellucida and pierces the plasma membrane of a secondary oocyte
it triggers the resumption of the second meiotic division with the formation of two new cells, the ovuma dn teh second polar body.
fertilisation is completed when the male haploid pronucleus and the female haploid pronucleus fuse, forming a diploid cell known as a zygote.
71
what does the process of implantation of the zygote involve?
the zygote undergoes mitotic cell division (cleavage) and is transformed into a milticellular structure (morula) which requires about 3 days to travel through the oviduct and enter the uterus.
the conceptus (preimplantation and surrounding membranes) acquires a fluid-filled cavity and becomes a blastocyst
the blastocyst implants in the endometrium of the uterus and is surrounded by an inner cellular layer, the cytotrophoblast and an outer multinucleated layer the syncytiotrophoblast.
the syncytiotrophoblast further invades the endometrium in the wall of the uterus by the sixth day after fertilisation. formation of the placenta then begins.
72
what is the wall of the vagina composed of?
the vagina is a fibromuscular canal with a wall that is composed of 3 layers:
1. mucosa
2. muscularis
3. adventita
it is circumscribed by a skeletal muscle sphincter at its external orifice
73
how is the vagina lubricated?
the vagina lacks glands throughout its length and is lubricated by secretions from the cervix and by seepage os the extracellular fluid from the vascular supply of the lamina propria.
74
what is the mucosa of the vagina composed of?
the mucosa of the vagina is composed of a thick, stratified squamous nonkeratinised epithelium and a fibroelastic connective tissue, the lamina propria.
75
what does the epithelial layer of the vagina contain?
the epithelia of the vagina contain glycogen. glycogen is released, which is used by the normal bacterial flora of the vagina to manufacture lactic acid.
the lactic acid lowers the pH during the follicuar phase of the menstrual cycle and inhibits invasion by pathogens
