Reproductive System: Female Flashcards
Primary sex organs of the female reproductive system:
Ovaries
◦ Produce ova gametes & secrete sex hormones (estrogens & progesterone)
Internal genitalia of the female reproductive system (located in pelvic
cavity):
ovaries & duct system
(uterine tubes, uterus, & vagina)
External genitalia of the female reproductive system
Vulva – external
sex organs
Ovarian follicles are
Sac-like structures: oocyte (immature egg), encased
by one or more layers of different cells
Stages of ovarian follicle development:
◦ Primordial follicles
◦ Primary follicles
◦ Secondary follicles
◦ Antral (Graafian) follicles
Ovulation is
1 maturing follicle ejecting its oocyte from the ovary (approx. each month)
A ruptured follicle that transforms into a glandular structure which eventually degenerates is
Corpus luteum
◦ Continues to release hormones
◦ Can play important role during pregnancy before placenta forms
Functions of the uterine tubes (fallopian tubes or oviducts)
◦ Form beginning of uterine duct system
◦ Receive the ovulated oocyte, & provide a site for fertilization
◦ Does not have direct contact with the ovaries
Fimbriae are
Ciliated projections at end of tube closest to the ovary
◦ Create a current to move the ovulated oocyte from the peritoneal cavity into uterine tube
The uterus is
A hollow, thick-walled muscular organ that functions to receive, retain, & nourish a fertilized ovum
The major part of uterus is
Body
Narrow outlet of the uterus projecting into the vagina is
Cervix
3 layers of the uterine wall:
◦ Perimetrium – serous, outermost
◦ Myometrium – bulky, smooth muscle
◦ Endometrium – mucosal lining
Layer of endometrium that changes in response to ovarian hormone cycles
Functional layer
◦ Shed during menstruation in response to ↓progesterone from ovaries
Layer of endometrium that forms the new functional layer after menstruation
Basal layer
◦ Unresponsive to ovarian hormones
The vagina is a passageway for:
◦ Delivery of an infant & menstrual blood
◦ Receiving the penis & semen during sexual intercourse
The 3 layers of the vaginal wall are:
◦ Adventitia – outer, fibroelastic
◦ Muscularis – middle, smooth muscle
◦ Mucosa – inner, ridged (epithelial cells produce a glycogen-rich fluid that
is metabolized by bacteria into lactic acid to produce an acidic environment of pH 4.5 for protection)
An adipose-rich rounded area overlying the pubic symphysis
Mons pubis
2 elongated folds of skin that extend posteriorly from mons pubis (homologous to scrotum)
Labia majora (singular labia majus)
2 thin folds of skin enclosed by labia majora (homologous to spongy urethra)
Labia minora
Recess enclosed by labia minora, containing vaginal & urethral openings
Vestibule
Paraurethral glands or female prostate
Skene’s glands
◦ Homologous to penile prostate
Produce lubricating fluid
Bartholin’s glands (greater vestibular glands)
◦ Homologous to male bulbourethral glands
Highly innervated erogenous zone of erectile tissue anterior to the vestibule
Clitoris
◦ Homologous to the penis
The ovarian cycle is
Set of events that occur in the ovaries in relation to development, maturation,
& ovulation of an oocyte
At the same time as the ovarian, the uterine (menstrual) cycle prepares
The endometrium for a fertilized ovum that can result in pregnancy
Female reproductive cycle refers to both
The ovarian & uterine
cycles, & hormonal changes that occur throughout body
Follicular phase:
Follicle develops & oocyte within it undergoes meiosis
◦ Follicle-stimulating hormone (FSH) promotes growth of dominant follicle
During follicular phase, ovulation occurs when
The ovary wall ruptures & a secondary oocyte is expelled
◦ following a peak in luteinizing hormone (LH)
Luteal phase:
Formation of corpus luteum that secretes progesterone & some estrogens
If a pregnancy occurs in luteal phase:
Corpus luteum persists until matured placenta takes over its hormone-producing role (~ 3 months)
If a pregnancy doesn’t occur in luteal phase:
Corpus luteum starts degenerating into corpus albicans & hormone release ends
During childhood release of gonadotropin-releasing hormone (GnRH) is inhibited by
Growing ovaries secreting small amounts of
estrogens
At puberty release GnRH is stimulated by
◦ Hypothalamus becoming less sensitive to estrogens
◦ Begins to release GnRH in a rhythmic manner
◦ Once the adult pattern of hormone cycles is established – the first menstrual cycle, menarche, occurs
Effects of LH in the female reproductive system:
Initially stimulates androgen release from thecal cells (converted to estrogen by granulosa cells)
Effects of FSH in the female reproductive system:
Main effects on granulosa cells of maturing follicles to release estrogens
In females release of GnRH & FSH is inhibited by
Moderate levels of estrogen in the blood plasma
◦ exerts negative feedback on hypothalamus & anterior pituitary
Function of inhibin in females:
◦ Inhibits FSH release
◦ Released by granulosa cells
Effect of high levels of estrogen from the mature follicle just before ovulation:
Briefly exerts positive feedback on the anterior pituitary; leading to ↑LH
LH surge just before ovulation:
◦ Triggers secondary oocyte maturation & ovulation
◦ Stimulates formation of corpus luteum from ruptured follicle & its secretion of progesterone & some estrogens (important for endometrium maintenance)
In ovulation secretion of progesterone, estrogen, & inhibin by corpus luteum inhibits
Release of GnRH, LH, & FSH via negative feedback
LH levels fall & corpus luteum degenerates leading to ↓estrogen/progesterone if
Fertilization does not occur
The uterine menstrual cycle is a series of cyclic changes that the uterine endometrium goes through each month in response to
Changing levels of ovarian hormones in the blood
◦ Coordinated with ovarian phases
During the Menstrual phase of the uterine cycle (Days 1–5):
◦ Endometrium is shed from uterus
◦ Ovarian hormones are at their lowest levels, & gonadotropins are beginning to rise
During the Proliferative (preovulatory) phase of the uterine cycle (Days 6–14):
◦ Endometrium is rebuilt: rising estrogen levels generate new functional layer of endometrium (thickens as the glands enlarge & spiral arteries increase in number)
◦ Cervical mucous thins to facilitate sperm entry into uterus
◦ Ovulation occurs at day 14
During the Secretory (postovulatory) phase of the uterine cycle (Days 15–28):
◦ Endometrium prepares for implantation of an embryo
◦ Rising progesterone (from corpus luteum) acts on estrogen-primed endometrium: spiral arteries convert
functional layer to secretory mucosa (produces nutrients to sustain embryo until implantation)
◦ Cervical mucous thickens: forms cervical plug to block entry of sperm/pathogens
End of uterine cycle if fertilization doesn’t occur:
◦ Corpus luteum degenerates leading to ↓progesterone: spiral arteries kink & spasm (cutting off oxygen & nutrients); functional
endometrium dies and sloughs off
◦ ~2/3 of endometrium is reabsorbed, rest is shed in menstruation
During puberty, rising estrogen levels promote:
◦ Oogenesis & follicle growth in ovary
◦ Growth & function of female reproductive tract
◦ Growth spurts in puberty
Estrogen-induced secondary sex characteristics:
◦ Breast development
◦ ↑deposition of subcutaneous fat in hips & breasts
◦ Widening & lightening of pelvis
◦ Metabolic effects: ↓blood cholesterol; facilitate bone Ca2+ uptake
Function of progesterone
Works with estrogens to establish & regulate uterine cycle & promote changes in cervical mucous
