Lecture 24 -- review questions Flashcards
which are the primary sex organs (gonads) in females?
ovaries
why are the ovaries considered “primary sex organs”?
they produces egg cells (ova) and sex hormones
what tube connects the ovaries with the uterus?
uterine tube / oviducts / fallopian tubes
what are other names for the uterine tube?
oviducts
Fallopian tubes
what are the parts, in order, of the uterine tube?
(1) infundibulum
(2) ampulla
(3) isthmus
(4) uterine part
what is the function of the fimbriae of the Fallopian tube?
smooth muscle and ciliated cells that create currents for egg to move through uterine tube
what are the 3 regions of the uterus?
fundus
body
cervix
what are the 3 layers of the uterine wall?
perimetric (most superficial)
myometrium
endometrium (deepest)
is the myometrium composed of smooth or skeletal muscle?
smooth
where is the cervical canal?
connects uterus to vagina
between the internal os (superior opening) and external os (opening into vagina)
what is the internal os?
and the external os?
superior opening of uterus to cervical canal
opening from cervical canal into vagina
what are the structures that the egg must cross thru its way from its site of production to the exterior of the female body?
(1) ovary
(2) uterine tube
- infundibulum
- ampulla
- isthmus
- uterine part
(3) uterine cavity
- internal os
- cervical canal
- external os
(4) vagina
what is the pH of the vagina?
why keep that pH?
3.5-4
inhibits growth of pathogens
does the vagina contain rugae, or is its surface smooth?
contains rugae
friction ridges to allow for stimulation during intercourse
what is the hymen?
a membrane at the vaginal orifice –> formed when the mucosa folds inward, forming a membrane
what is an ovarian follicle?
small sacs filled w/ fluid where immature eggs develop
where does folliculogenesis occur, in the ovarian cortex or medulla?
ovarian cortex
contains thousands of ovarian follicles in various stages of development
what does the ovarian medulla contain?
stromal medulla
loose connective tissue w/
- abundant blood vessels
- lymphatic vessels
- nerve fibers
how many oocytes are in a follicle?
1
what is oogenesis?
process of egg production in the ovaries
what is the name of the stem cells that produce primary oocytes? (in sing and pl)
oogonium
oogonia
does the oogonium have 46 or 23 chromosomes?
46
diploid
do all the primary oocytes start meiosis I before birth?
yes; all arrested in prophase of meiosis I until puberty
do all primary oocytes finish meiosis I before birth?
no; stay in prophase of meiosis I until puberty
how often does a primary oocyte complete meiosis I after puberty?
once a month
when a primary oocyte finishes meiosis I, what are the resulting cells called?
secondary oocyte (oocyte II)
first polar body
what is the function of the first polar body? when is it created?
created after primary oocyte undergoes completes meiosis I
first polar body discards the extra haploid set of chromosomes
when does a primary oocyte complete meiosis I, before or after ovulation?
after
meiosis I is completed on the day of ovulation
at what point does the secondary oocyte complete meiosis II? (tip: before being fertilized by sperm or after it?)
after being fertilized by sperm
what is produced in meiosis II of a secondary oocyte?
ootid
second polar body
first polar body also divides into 2 new polar bodies
at what end of meiosis (I or II) is the secondary oocyte produced?
meiosis I
forms secondary oocyte and first polar body
at what end of meiosis (I or II) is the ootid produced?
meiosis II
forms ootid and second polar body
at what end of meiosis (I or II) is the second polar body produced?
meiosis II
forms second polar body and ootid
which cells are diploid: oogonium, primary oocyte, secondary oocyte, ootid, or ovum?
oogonium
primary oocyte
(primary oocyte becomes haploid after meiosis I is completed –> secondary oocyte)
when is the ovum formed?
fertilized ootid –> matures into ovum (fully mature human egg cell)
oogonium
– prophase of Meiosis I –
primary oocyte
– completion of Meiosis I –
secondary oocyte
– fertilization –
– Meiosis II –
ootid –> ovum
what happens in the end with the polar bodies generated during oogenesis?
they are nonfunctional and degenerate
is oocyte another word for immature (or developing) egg?
yes
oocyte == immature (or developing) egg
what is the medical term for a mature egg?
ovum
(plural ova)
are you born with all your primary oocytes, or can you still produce them after birth?
yes; you are born with all your primary oocytes
no; you cannot produce them after birth
if the egg is not fertilized, it will disintegrate. In which state of oogenesis will be at that moment?
secondary oocyte
what is the order of cells produced in oogenesis (from oogonium to ovum)?
(1) oogonium
- stem cell
(2) primary oocyte
- prophase of Meiosis I
(3) secondary oocyte + first polar body
- completion of Meiosis I
(4) ootid + second polar body
- secondary oocyte gets fertilized + completion of Meiosis II
(5) ovum
- ootid matures into ovum
what is the reproductive cycle?
sequence of events from fertilization to giving birth and returning to a state of fertility
what is the sexual cycle?
encompasses the events that recur every month when pregnancy doesn’t intervene
what 2 cycles form part of the sexual cycle?
ovarian + menstrual cycle
what is the ovarian cycle?
consists of events in the ovaries
what are the 2 phases of the ovarian cycle?
follicular + luteal phase
what is the main event happening during the follicular phase of the ovarian cycle?
development of the ovarian follicles in response to FSH
when does the luteal phase start and finish?
starts w/ formation of corpus luteum
ends in pregnancy or luteolysis (destruction of corpus luteum)
what is the length of the follicular phase?
and the luteal phase?
follicular phase == 13-14 days (ends in ovulation)
luteal phase == 12-14 days
both ~ 2 weeks
what is the menstrual cycle?
aka uterine cycle
part of sexual cycle
consist of parallel changes in the uterus
consists of the buildup of the endometrium thru most of the sexual cycle, followed by its breakdown and vaginal discharge
what is another name for the menstrual cycle?
uterine cycle
what is folliculogenesis?
follicle development
(as an egg undergoes oogenesis, the follicle around it undergoes folliculogenesis, passing thru different stages)
what are the different stages in follicle development in order?
1) primordial follicle
2) primary follicle
3) secondary follicle
4) tertiary/early vesicular/antral follicle
5) Graafian/mature follicle
what is a primordial follicle made of?
primary oocyte in early meiosis
primary oocyte + nucleus + 1 layer of squamous follicular cells
what is the main difference b/n the primordial and primary follicles?
primordial == squamous follicular cell layer
primary == cuboidal follicular cell layer
squamous –> cuboidal
which follicles contain primary oocyte in early meiosis: primordial, primary, secondary, tertiary, Graafian follicles?
primordial follicle
what is a secondary follicle made of?
+2 layers of granulosa cells
3 layers total
oocyte + granulosa cells + zona pellucida + theca follicli
where can you find the zona pellucida? and the theca follicluli?
in the secondary follicle
which cells of the follicle produce androgens? and estrogens?
androgens –> endocrine cells of the theca folliculi
estrogens –> granulosa cells
what is the antrum made of?
the fluid b/n the granulosa cells coalesces to form the antrum (large fluid-filled cavity)
what is the cumulus oophorous?
mound of granulosa cells that covers the oocyte and secures it to the follicle wall
where is the corona radiata in the follicle?
innermost layer of cells in the cumulus oophorus
what is a Graafian follicle?
a mature follicle
characterized by an antrum, cumulus oophorus, and theca cells
what happens to the Graafian follicle during ovulation?
Graafian follicle would rupture and the secondary oocyte would be released into the fallopian tubes
how many Graafian follicles break, releasing the secondary oocyte, during ovulation?
usually only 1 Graafian follicle breaks –> releases the secondary oocyte
the rest die
usually only 1 per month (dominant follicle) matures and ovulates. the rest die.
what does the Graafian follicle form into just after ovulation?
corpus luteum
what hormone stimulates the anterior pituitary gland to release FSH?
GnRH
which are the structures responsible for secreting estrogen during the follicular phase?
granulosa cells
what are the effects of estrogens on the ovarian follicle?
up-regulates the mature follicle’s receptors for FSH, LH, and estradiol
what are the effects of FSH on folliculogenesis?
increases the growth and maturation of immature oocytes into mature (Graafian) secondary follicles before ovulation
what is a “dominant follicle”?
the follicle that has the most receptors for FSH
–> consumes the most FSH –> develops the most –> becomes the mature Graafian follicle that gets ovulated
is it normal to have more than 1 dominant follicle?
sure;
if more than one follicle ovulates –> leads to non-identical multiple gestations –> fraternal twins
what happens to the other follicles after one becomes dominant?
dominant follicle secretes estrogen and inhibin –> exerts negative feedback on FSH –> “turns off” neighboring astral follicles –> atresia –> radical apoptosis of all cells w/in the follicle, including the oocyte
what is atresia?
radical apoptosis of all cells w/in the follicle, including the oocyte
what 2 phases of the menstrual cycle happen at the same time as the follicular phase of the ovarian cycle?
menstrual
proliferative
what are the 2 main layers of the endometrium?
functional layer
basal layer –> rebuilds the functional layer
what happens to the endometrium during the menstrual phase of the uterine cycle?
functional layer of the endometrium degenerates (sloughs off in menses)
due to lack of blood flow
which layer of the endometrium degenerates and is shed during the menstrual phase?
functional layer
what event determines the first day of the menstrual cycle?
first day of discharge
what happens to the endometrium during the proliferative phase of the uterine cycle?
new functional layer layer of endometrium is rebuilt
caused by increased estrogen
during the proliferative phase, restoring the endometrium is due to cell mitosis or to the accumulation of secretions from the uterine glands?
cell mitosis
uterine gland basal cells multiply and spread
what hormone stimulates the proliferation of the cells building up the function layer of the endometrium?
which structure produces this hormone?
estrogen
granulosa cells in the primary/secondary follicle
what receptors do estrogen increase in the endometrium? (tip: they are preparing the endometrium for the luteal phase and pregnancy)
progesterone receptors
in which phase of the menstrual cycle does menses occur?
Menstrual phase
what 2 hormones stimulate the secretion of LH before ovulation?
GnRH
estrogen
where does LH come from? (gland)
anterior pituitary gland
what is the role of LH in the period of time close to ovulation?
completion of meiosis I by the primary oocyte
forceful rupture of the follicular wall
ovulation (~9 hr after LH peak)
do you ovulate at the same time as your LH surge?
no;
LH surge occurs before you ovulate
what is ovulation?
rupture of mature follicle and release of secondary oocyte into the Fallopian tubes
(induced by a large burst of LH secretion)
what is the role of LH after ovulation?
causes conversion of the ruptured follicle to a corpus luteum (produces estrogen and progesterone)
what hormones does the corpus luteum secrete?
estrogen and progesterone
what happens to the corpus luteum if fertilization does not occur?
corpus luteum dies and forms the corpus albicans
what hormones stimulate the uterine glands to secrete nutrients and fluid responsible for the thickening of the endometrium during the secretory phase?
estrogen and progesterone
if the corpus luteum degenerates, what happens to estrogen and progesterone levels?
estrogen and progesterone levels decrease
–> no more blood supply to functional layer –> GnRH and FSH increase –> get ready for new cycle
only occurs if fertilization does not occur
what causes the spiral arteries to become spastic and cut off the blood supply of the functional layer of the endometrium at around day 28?
why do GnRH and FSH increase their levels at that point?
corpus luteum becomes corpus albicans –> no longer secretes estrogen and progesterone
GnRH and FSH increase levels to start new ovarian cycle
–> allow folliculogenesis to occur
–> more estrogen gets produced by the granulosa cells of the follicles
–> more estrogen == rebuild functional layer
== more progesterone receptors
== more uterine secretions
–> rebuild endometrium
what days does the corpus luteum form?
~day 16-18
occurs after ovulation (day 14)
what is the corpus albicans?
corpus albicans does not secrete estrogen or progesterone
knot of pale scar tissue produced by fibroblast
formed by degeneration of the corpus luteum when fertilization doesn’t occur
marks the end of the ovarian cycle
why do progesterone levels significantly increase during the luteal phase?
corpus luteum is being formed –> corpus luteum secretes a lot of estrogen and progesterone –> helps increase progesterone levels a lot since estrogen helps increase progesterone receptors
why do LH and FSH levels decrease when progesterone and estrogen increase during the luteal phase?
high levels of progesterone and estrogen cause negative feedback loop on anterior pituitary gland –> less LH and FSH produced
what is menopause?
cessation of ovulatory function (ovulation and menstruation cease) –> occurs naturally, as a result of declining levels of estrogen and progesterone
does a 45-yr-old female have more, less, or the same number of primordial follicles as a 21-yr-old female?
less
you’re losing a bunch of follicles –> decrease in estrogen –> less FSH receptors in follicles –> follicles don’t mature into Graafian follicles and keep dying
the decrease in which hormones trigger menopause?
estrogen
progesterone
what happens to the vagina after menopause?
and to the skin and bones?
vaginal flexibility decreases
vaginal lining thins and becomes dry
less blood flow to vaginal tissue
skin more dry, dull, and wrinkly
bone mass decreases
why does the risk of cardiovascular diseases increase in females after menopause?
estrogens has a protective role on blood vessels against cholesterol plaques
at what age does a woman usually stop ovulating? (approximately)
45-55
avg 52
