Downing: Female Reproductive System Flashcards
What are the exocrine fxn of the ovary?
Production of eggs (ova)
What are the endocrine fxns of the ovary?
(1) Estrogen production: by theca interna cells and granulosa cells
(2) Progesterone production: by corpus luteum (lutein cells)
What components form the suspension of the ovary?
- Mesovarium
- Peritoneal covering (simple cuboidal)
- Hilum (attachment site to the mesovarium, conduit for BV, N, L)
How many primary oocytes finish maturation/month?
ONE!
What stage is the secondary oocyte arrested in until fertilization?
metaphase II
What part of the follicle contains the primary oocyte in prophase I that is arrested until just before ovulation?
Primordial follicle
Where are follicular cells found? What receptors are found on follicular cells?
primordial follicles
FSH receptors
Twenty to fifty primordial follicles respond to FSH every cycle to form…
primary follicles
What are granulosa cells?
follicular cells become columnar/stratified= granulosa cells
What are theca folliculi?
Stromal cells that surround the granulosa cell
What forms the zona pellucida? What is it?
Granulosa cells and oocyte> zona pellucida
gel like neutral glycoprotein
What happens in the primary follicle after menarche?
one follicle completes the developmental process and becomes the DOMINANT follicle and the rest undergo atresia
What characterizes secondary follicles?
- Primary oocyte still in prophase I
- antrum formation (liquor folliculi, FSH, inhibin proteins)
- granulosa cells surround the oocyte
- theca folliculi
How does the antrum develop?
begins as a small space between granulosa cells>
becomes confluent to form the antrum
What are the two distinct portions of the theca folliculi?
- theca interna (androgen production> androgen precursors, highly vascular)***
- theca externa (fusiform cells and collagen)
How long does total maturation of follicles take?
3 months
What is the corona radiata?
(1) Follicle cells in direct contact with egg
(2) Cells are radially arranged around zona pellucida
When does the theca folliculi reach its greatest develoipment?
In mature follicles
What happens when the LH signals final maturation?
resumption of meiosis:
1o oocyte → 2o oocyte–> production of first polar body
**2o oocyte arrests at metaphase II
until fertilization
What happens during ovulation?
LH surge> granulosa and theca cells receptive> one follicle responds> meiosis I is completed> 1st polar body extrusion> arrest at Met II> stigma formation> rupture and expulsion of cumulus mass> ovum capture by oviductal fimbria
What is stigma formation and how does it lead to the release of the ovum?
Follicular wall adjacent to tunica albuginea weakens> Decreased blood flow> Putative protease release> rupture and expulsion of cumulus mass> ovum capture by oviductal fimbria
What does FSH promote?
Granulosa cell growth and estrogen synthesis
Later it increases LH receptors, increasing the responsiveness of granulosa and theca interna cells to LH
What stimulates thecal cell growth and androgen production as well as progesterone production in granulosa cells?
LH
granulosa cells convert androgen to estrogen
What happens to the dominant follicle during every month?
Secretes estrogen>
Result is a LH (and FSH) surge that triggers ovulation
What is the corpus luteum?
Temporary glandular structure derived from the RUPTURED FOLLICLE after ovulation
What two cell types are affected by the LH surge?
- Granulosa cells = increase in size, produce PROGESTERONE and continue to secrete estrogen (granulosa luteum)
- Theca interna = increases in size and form theca luteum (secrete progesterone and some estrogen)
How does the CL of preganancy differ from that of menstruation?
Pregnancy: formed after implantation>
becomes LARGER than CL of menstruation
Menstruation: forms after ovulation, lasts 14 days, if embryo doesn’t develop involutes and forms CORPORA ALBICANS
What maintains the corpus luteum of pregnancy?
HCG prodoced by trophoblasts
How long does the CL of pregnancy last?
persists during first trimester and involutes to reduced scar tissue
What produces estrogen?
Produced mainly by growing follicles (granulosa cells, convert androgen to estrogen) (high preovulatory levels)
What are the fxns of estrogen?
Induces maturation of female reproductive tract and mammary glands
Directs repair of uterus following menstruation
Influences growth of mammary glands in pregnancy
What produces progesterone?
corpus luteum
What are the fxn of progesterone?
Causes uterine glands to secrete
Prepares uterus for implantation of fertilized ovum
Aids in growth of mammary gland
Inhibits uterine contractions
What produces relaxin?
CL and decidual cells
What are the actions of relaxin?
(1) Inhibits contractions by myometrium during pregnancy)
(2) Promotes dilatation of cervix (softens it)
(3) Loosens symphysis pubis (in some species)
Where is inhibin found and what does it do?
produced by granulosa cells
follicular fluid
NFB on FSH release
What are Atretic follicles?
Only 400 follicles reach maturity. The majority undergo involuntion = FOLLICULAR ATRESIA
What is the first and last part of the follicle to become atretic?
Ovum
degeneration of follicular cells follow
theca interna cells degrade last
What are the two zones of the ovary?
Medulla and cortex
What are the two components of the cortex?
tunica albuginea (between epithelium and developing follicles)
Where are follicles located in the ovary?
stroma
What is the origin of primordial germ cells?
yolk sac, migrate to ovaries early on in fetal life
How many eggs eventually mature and ovulate?
400-500
What happens to primordial germ cells?
migrate to ovary in the first trimester and have 46 chromosomes, they’re surrounded by follicular cells which is the primordial follicle
What happens in the third fetal month TO OOGONIA?
Oogonia enlarge>
become primary oocytes>
arrested in prophase I of first meitotic division (12-50 years)
*arrested in PRO
What happens to the atretic follicle?
replaced by scar tissue
Where is the oviduct located?
w/in the broad ligament
extends from ovary to uterus
What are the divisions of the oviduct?
ampulla (infundibulum and fimbriae)–closest to ovary
isthmus
intramural segment- embedded in wall of uterus
What part of the oviduct is characterized by elaborate branching folds, a large diameter, and a simple ciliated columnar epithlieum?
ampulla
- beat of cilia moves eggs towards uterus
- PEG cells= secretory cells between ciliated cells, provide nutrition to egg and sperm
What stimulates ciliated cells?
estrogen
What affects height and number of peg cells?
progesterone
estrogen stimulates secretory activity
What part of the oviduct has fewer folds than the ampulla, reduced ciliated cells but active secretory cells?
isthmus
What part of the oviduct has insignificant folds and no cilia?
intramural segment
what is responsible for embryo transport through the isthmus during the lateral phase?
tubal peristalsis by the muscularis
What causes oviduct dysfxn?
occlusion (scar tissue)
ectopic pregnancy
tubal ligation
What are the three major layers of the uterus?
endometrium (mucosa)
myometrium (muscularis)
perimetrium (serosa)
Describe the epithelium of the endometrium.
simple tubular glands
simple columnar
ciliated where glands open
cells in glands are SECRETORY w/ onset of progesterone production
What underlies the epithelium?
LP
CELLULAR
What are the two major zones of the endometrium?
basal layer
functional layer
What is the outer most zone of the endometrium?
basal layer deepest narrow does NOT shed RESPONSIBLE FOR REGENERATING FXNAL LAYER
What are the subdivisions of the functional layer?
- superficial
(narrow, shows little edema, contains straight portions of tubular glands) - deep spongy layer
What’s the broader zone of the functional layer that comprises the bulk of the endometrium? Is it edematous? How do the glands compare to those of the superficial layer?
deep spongy layer
edematous
glands are tortuous and have large lumens
What is the myometrium?
mass of SMOOTH MUSCLE
Which layer of the myometrium is vascular?
middle
How is the myometrium hormone responsive?
muscle fibers:
shortest in first week after menstruation
longest in 4th week of cycle
What happens to the myometrium during pregnancy?
hypertrophy (10x)
some hyperplasia
What is the perimetrium?
outer mesothelial lining
Describe the blood supply to the uterus.
Uterine arteries>
arcuate arteries> spiral arteries > capillaries
straight arteries> capillaries
Where are the uterine arteries?
broad ligament
Where are the arcuate arteries?
myometrium
Where are the spiral arteries?
functional layer
Where are the straight arteries?
basal layer
How long is the average menstrual cycle?
29 days
What is considered the first day of the menstrual cycle?
first day of menstruation
When is the proliferative phase?
day 7-14
What induces the proliferative phase?
Begins at the end of menstrual flow, induced by ESTROGEN
What is the proliferative phase dependent on?
estrogen (thecal output)
What happens to the endometrium during the proliferative phase?
2-3x increase in endometrial thickness (functional layer)
d/t mitosis in glands and stormal cells
What happens to the straight tubular glands during the proliferative phase?
increase in number and length
cells accumulate GLYCOGEN in basal portion
When is the secretory phase of the menstrual cycle?
days 15-26
What happens during the secretory phase?
Ovulation precipitates CL formation>
increase in PROGESTERONE AND ESTROGEN> thickening continues d/t edema (in stroma) and accumulation of nutritive materials
Coiled arteries elongate and extend into the superficial portion of the endometrium
What is the premenstrual phase?
days 27-78
What happens during the premenstrual phase?
If preg doesn’t occur>
CL begins regression and you get decreased steroid output (decreased progesterone/estrogen)
Reduced endometrial edema.
Anoxia induces tissue necrosis.
What happens to coiled arteries during the premenstrual phase?
Coiled arteries constrict intermittently in response to the decline in progesterone and eventually constrict permanently.
Terminal portions DIE and the endometrium begins to detach.
Arterioles bleed directly into denuded areas
Leukocytic infiltration
When is the menstrual phase?
days 1-4
When is the repair phase?
days 5-6
What happens during the menstrual phase?
Endometrium undergoes complete necrosis and is shed and you get venous seepage b/c blood can’t clot d/t FIBRINOLYSIN.
The denuded surface is re-epithelialized and coiled arteries begin regrowth
Describe the mucosal epithelium of the cervix.
Simple columnar w/ branching glands that produce MUCOUS, some cells are ciliated w/ an ABRUPT TRANSITION to stratified sq nonk at the cervical os.
What is significant about hte squamocolumnar jxn?
site where most precancerous lesions and carcinomas of the cervix develop
What is cervical dilation (in late pregnancy) of the myometrium dependent on?
relaxin
collagenolysis
Describe the mucosal epithelium of hte vagina.
stratfied sq non-k
cells become loaded w glycogen
ESTROGEN sensitive
What happens to the vaginal mucosa during the follicular phase?
proliferation and hypertrophy of basal cells
glycogen uptake
exfolidated cells are eosinophilic
What happens to the vaginal mucosa during the luteal phase?
decrease in epithelial height
exfoliated cells are basophilic
leukocytes appear and are shed into the lumen
What forms the vaginal orifice?
striated fibers of bulbocavernosus muscles form a type of sphincter around the ostium of the vagina
What creates a low ph in the vagina?
glycogen serves as a metabollite for lactobacilli>
lactic acid>
lowers pH>
restricts pathogenic invasion
What nerve endings are found in the external genitalia?
Meissner’s corpusles (mons pubis and labia majora)
Pacinian corpuscles (deep layers of connective tissue–labia majora and eretile tissue)
Free nerve endings (skin of external genitalia)
