A&P400 (Female reproductive system) Flashcards
overall function of female reprodutiv esystem
Produces sex hormones
Produces functional gametes
Protects and supports developing embryo
Maintains growing fetus
Nourishes newborn infant
female external genitalia
Vulva (outer genitals)
and urethra
Female internal genitalia
Ovaries,
uterine (Fallopian) tubes,
uterus,
vagina
Mammary gland of breast
Produces milk to nourish infant
female gonads are
OVARIES
ovaries produce
gametes
(oocytes that mature into ova)
ovaries also produce
Produce hormones
female reproductive tract
uterine tubes (fallopian tubes)
uterus
vagina
uterine tubes
(deliver oocyte or embryo to the uterus)
—> Normal sites of fertilization (endometrium)
site of fertiization
“a fertilized egg usually attaches to (implants in) the lining of the uterus (endometrium).
“
uterus
(site of embryonic and fetal development)
—> Also site of exchange between maternal and embryonic/fetal bloodstream
vagina
Birth canal during delivery
Passageway for fluids during menstruation
external genitalia
Mons pubis
clitoris
labia (majora/minora)
Mons pubis
Pad of fatty tissue overlapping symphysis pubis
clitoris
Contains erectile tissue
labia
Contain glands that lubricate the entrance to the vagina
—> E.g. Greater vestibular glands (analogous to bulbourethral glands of males)
mammary glands
Produce milk to nourish newborn infant
ovaries
Paired almond-shaped organs near the lateral wall of the pelvic cavity
three main functions of ovaries
1) oogenesis
2) secretion of hormones
3) secretion of inhibin
1) oogenesis
production of immature female gametes (oocytes)
2) Secretion of female sex hormones
(estrogens and progesterone)
secretion of inhibin
(inhibits FSH production in the anterior pituitary gland)
ovary is held in place by
ligaments
AKA
proper ovarian ligament
other ligaments stabilizing ovaries
1) Ovarian ligament
2) Mesovarium
3) Suspensory ligament
4) Broad ligament
1) Ovarian ligament
Extends from uterus to medial surface of ovary
2) Mesovarium
Fold of mesentery; supports and stabilizes ovary
3) Suspensory ligament
Extends from lateral surface of ovary to pelvic wall
4) Broad ligament
Extensive mesentery enclosing ovaries, uterine tubes, and uterus
Attaches to sides and floor of pelvic cavity
layers of the ovaries
1) germinal epithelium
2) tunica albuginea
3) interior of ovary
1) Germinal epithelium
Layer of squamous or cuboidal cells covering the ovary
Continuous with the visceral peritoneum
2) tunica albuginea
Dense connective tissue layer just deep to the germinal epithelium
Interior of the ovary
a) Cortex (superficial layer holding follicles where oocytes are produced)
Medulla (deep to the cortex, loose CT w/ blood vessels)
THE CORTEX of ovaries
Contains:
ovarian follicles
& dense irregular CT
ovarian follicles
a developing oocyte surrounded by one or more layers of cellscalled follicular cells
mature follicles (Graafian follicles)
large, fluid filled follicle that is ready to rupture its secondary oocyte (ovulation)
secondary vs primary oocyte
A secondary oocyte is an oocyte in the period between the first and second maturation division; it is derived from a primary oocyte shortly before ovulation by a division that splits off the first polar body. If fertilized, it divides into an ootid and the second polar body; otherwise, it perishes.
corpus luteum
remnants of follicle after ovulation that produces progesterone, estrogens, relaxin & inhibin
until it degenerates into scar tissue (corpus albicans)
layers of ovaries
Follicles at various stages of development
Corpus luteum
Corpus albicans
Oogenesis and the ovairan cycle
..o
oogenesis
formation and development of the oocyte
oogenesis occurs where
occurs inside a follicle
when does oogenesis actually occur first? when does it continue? when doe sit end
begins before birth, accelerates at puberty, ends at menopause
nuclear events of oogenesis vs spermatogenesis
nuclear events are very similar as with spermatogenesis
OVARIAN CYCLE
development of the follicle
—> occurs along side of oogenesis
development ends in the rupture of mature follicle (ovulation)
becomes the corpus LUTEUM and eventually corpus ALBICANS
when does oogeneiss begin
Begins in early fetal development in females
step 1 of oogenesis
Primordial germ cells migrate from yolk sac to ovaries
Germ cells differentiate into oogonia (2n – diploid?) that continue to divide mitotically to produce millions of germ cells
what happens to most of these germ cells before birth?
WHAT HAPPENS TO SOME?
Before birth, most of these germ cells degenerate through ATRESIA
A few develop into primary oocytes (2n)
atersia define
- : absence or closure of a natural passage of the body. 2. : absence or disappearance of an anatomical part (such as an ovarian follicle) by degeneration.
without
perforation
STEP 2 OF OOGENESIS
Beginning between 3rd and 7th month of fetal development, primary oocytes enter meiosis
—> arrest in prophase of meiosis I during fetal development
what is (primary?) oocyte called when arrested in prophase of meiosis 1 during fetal development?
CALLED A PRIMORDIAL FOLLICLE
—> “During this time, it is surrounded by one layer of follicular cells and is called a primordial follicle”
—> Stay here until puberty
how long do primordial follicles stay there?
Stay here until puberty
how many primordial follicles at birth
how many @ puberty?
how many ovulated over lifetime?
between 200,000 to 2million present at birth
40,000 remain at puberty
About 500 oocytes are ovulated over life time
Most are lost to ATRESIA
how many eggs @ menopause?
Less than 10,000 eggs at menopause, non-functional
STEP 3 OF OOGENEISS
Starting at puberty and ending at menopause
Each month, follicle stimulating hormone (FSH) from anterior pituitary stimulates some of the primary oocytes to complete meiosis I
what happens after FSH from anteiror pituitary stimulates PRIMARY oocytes?
complete meisis 1
—> Yields HAPLOID secondary oocyte and a polar body
—-> Secondary oocyte gets the majority of cytoplasm
STEP 4 OF OOGENEISS
These secondary oocytes begin MEIOSIS II but are arrested in METAPHASE II
—> One (usually) secondary oocyte is released (ovulated) per month
STEP 5 OF OOGENESIS
At fertilization, the secondary oocyte divides into a SECOND POLAR BODY and a MATURE OVUM (both haploid)
THE OVARIAN CYCLE
….
the ovarian cycle occurs alongside
Occurs alongside oogenesis
Involves changes in ovarian follicles
—> Specialized structures where oocyte growth and meiosis I occur
how many PRIMORDIAL FOLLICLES @ BIRTH?
About 2 million primordial follicles exist at birth
Each containing a primary oocyte
by puberty, how many primordial folicles remain?
By puberty, only about 400,000 primordial follicles remain
—> Others degenerated in a process called atresia
each month ___ stimulates development of several follicles
Each month, FSH stimulates the development of several follicles
And development of the oocyte inside along with it (oogenesis)
two stages of ovarian cycle?
1) Follicular phase: development of the follicle
2) Luteal phase: development of the corpus luteum
STAGE 1 OF THE OVARIAN CYCLE
Primordial follicle in egg nest
Primordial follicle
—> Inactive primary oocyte surrounded by a simple squamous layer of follicle cells
EGG NESTS:
Clusters of primary oocytes
in the outer portion of the
ovarian cortex, near the
tunica albuginea
Stage 2 of ovarian cycle
Formation of primary follicles
—> Follicular cells enlarge, divide, and form several layers around the primary oocyte
what are follicular cells called when they enlarge, divide and form several layers around the the primary oocyte?
Follicular cells now called GRANULOSA cells
Zona PELLUCIDA (pellucidus, translucent)
Region that develops around the oocyte
—> “The zona pellucida is an extracellular matrix that surrounds the plasma membrane of the egg cell. It helps protect the egg, and has an essential role in fertilization by sperm.”
Thecal endocrine cells (theca, box)
Layer of cells that form around the follicle
“Theca cells are responsible for synthesizing androgens, providing signal transduction between granulosa cells and oocytes during development by the establishment of a vascular system, providing nutrients, and providing structure and support to the follicle as it matures.[2]”
what do thecal and granulosa cells do together?
Thecal cells and granulosa cells work together to produce ESTROGEN
Stage 3 of the ovarian cycle
Formation of secondary follicles
Follicle wall thickens, and follicular cells secrete fluid
—> Fluid-filled pockets expand and separate the inner and outer layers of the follicle