Reproductive Anatomy and Physiology Flashcards
explain sex differentiation in male development considering: Y chromosome, testes, Leydig cells, Sertoli cells, Wolffian ducts, and mullerian ducts
Y chromosome has a sex-determining region that releases SRY protein onto to gonadal tissue, causing the tissue to differentiate. Testis determining factor (TDF) influences gonadal tissues to become testes and they produce multiple proteins –> causing proliferation of Leydig, Sertoli cells, and Spermatogonia. Leydig cells proliferate and produce testosterone which activates Wolffian ducts to become the internal reproductive organs. Spermatogonia secretes DHT (Dihydrotestosterone) which becomes male external reprodutive organs. Sertoli cells produce Mullerian Inhibiting hormone which causes Mullerian ducts to regress
explain sex differentiation in females considering: oogonia, sertoli cells, mullerian ducts
Hint: Mullerian ducts become a MOM.
-no Y chromosome so gonadal tissue remains undifferentiated
-oogonia: primitive eggs/germ cell
-Sertoli cells do NOT produce MIH and in its absence the Mullerian ducts proliferate to become the fallopian tubes, uterus, and proximal vagina
T/F oogenesis begins in utero, where the peak number of follicles is @ 20 weeks gestation
TRUE
How is external genitalia formed in females
the genital tubercle (that is activated by DHT in males to become male external genitalia) becomes the clitoris
puberty development of females
- Thelarce (breast budding)
- Adrenarche (pubic hair)
- Growth Spurt Peak
- Change in body shape
- Growth of underarm hair
- Menstruation/Period
- adult breast size
The ad grew and changed to a hairy arm and bloody boob
If patient deviates from stepwise manner of female development, you should suspect….
hormone dysregulation
What is menopause? how is it defined?
-follicular atresia continues
-changes in menstrual cycle: no dominant ovarian follicle each month, menstruation ceases for 12 months
-average age is 52
-hormonal levels can fluctuate widely
-estradiol declines, ESTRONE dominates
-symptoms related to lack of estrogen and progesterone
how long after breast budding can we expect a period?
most girls get their first period within 2-3 years after development of breast buds
when should females who have not reached puberty or have not had a period be evaluated?
- no breast buds by age 13/signs of puberty by 13
- no period by age 15
causes of delayed menstruation in females
-poor nutrition, or eating disorders
-hereditary
-involvement in sports/athletics
menstrual cycle overview
FOLLICULAR PHASE
Day 0: first day of period!
Day 4-5: last day of period! LH is low, FSH is low, estradiol starts to build
Day 12-13: LH spikes in preparation for ovulation (ovulation occurs within 10-12 hours of LH peak), FSH increases
Day 14: Ovulation! LH, FSH, and estradiol decrease; body temp increases
LUTEAL PHASE
day 16: progesterone builds/corpus luteum develops
day 21: progesterones at its peak, endometrium is proliferating
day 28: progesterone falls, egg not fertilized = period
organs of the menstrual cycle
- hypothalamus (gnRH)
- anterior pituitary (LH and FSH)
- ovary (estrogen and progesterone provide negative feedback to hypothalamus and pituitary; also acts on endometrium)
- uterus (endometrium)
function of LH vs FSH
FSH- development of a dominant follicle
LH- primary
Where do steroid hormones come from/produced by?
-gonads and adrenals!!
-includes: androgens (testosterone), estrogens and progesterones
when does each of the following estrogens dominant in the females lifecycle:
1. estraDiol (E2)
2. estriol (E3)
2. Estrone (E1)
- estraDiol (E2): main estrogen of the reproDuctive years
- estriol (E3): secreted by the placenta (pregnancy!!)
- Estrone (E1): weakest estrogen, primary estrogen of menopause
estrogen effects
-reproductive tissues actions
-systemic effects/symptoms (breast, skeleton, metabolic, skin, renal)
REPRODUCTIVE TISSUE ACTIONS
-cellular proliferation and growth of tissues in reproductive organs
-ovarian follicle maturation
-proliferation of endometrial glands and spiral arteries
-contractions of the uterus and fallopian tubes
-Spinnbarkeit: fertile cervical mucus (watery, clear)
SYSTEMIC EFFECTS/SYMPTOMS
-breasts: stromal tissue, ducts, and fat
-skeleton: increased osteoblast activity (Blasts Build Bone)
-metabolic: slight increase in metabolic rate, deposition of SQ fat
-skin: stoftens texture, becomes more vascular (leads to increased warmth)
-renal: sodium and water retention
Progesterone Effects:
-reproductive tissue actions
-systemic effects (breasts, GI, pscyh, renal)
REPROCUTIVE TISSUES
-secretory changes in the endometrium (prepares uterus for implantation)
-smooth muscle quiescence (uterus, fallopian tubes, GI tract)
-thick, non-futile cervical mucous
SYSTEMIC EFFECTS
-breasts: development of lobules and alveoli
-GI: slowed motility, constipation
-Psych: labile and or depressed mood
Renal: enhances Na, Cl, H20 reabsorption in kidneys (bloating and water retention)
what is Mittelschmerz?
pain at ovulation
T/F: A temperature rise of .2 to .6 degrees C. confirms ovulation has taken place but does NOT predict it
TRUE
anatomy of the breast
-lobe: section of breast composed of glandular tissue and surrounded by faty and connective tissue radiating around the nipple; 15 to 20 in each breast
-lobules: small branching glands within each lobe contain tiny, hollow sacs called alveoli, which are responsible for milk production
-each lobe empties into single lactiferous duct that opens out through the nipple
-unique proliferation occurs under influence of estrogen during puberty
pelvic floor muscles function
-levator ani
-pubococcygeus
pelvic floor muscles along with ligaments and fascia support abdominal and pelvic organs, maintain continence, and facilitate passage of fetus during birth
vulva definition
visible external structures bordered by symphysis pubis anteriorly, buttocks posteriorly, and thighs laterally; develops as a secondary sex characteristc under influence of estrogen during puberty
Vulva structures
1. mons pubis
2. labia majora
-labia minora, clitoris, vestibule, perineum
- mons pubis: fatty tissue prominence overlying symphysis pubis
- labia majora encloses these structures:
-labia minora: thin folds inside/parallel to labia majora, encloses the vestibule and terminates in the fourchette above the perineum
-clitoris: small, erectile body of tissue; tons of sensory nerve endings; rich vascular supply
-vestibule: contains urethral/vaginal openings, hymen, Skene’s glands on each side of the urethral meatus, Bartholin’s glands with openings located posteriorly on each side of vaginal orifice
-perineum: between fourchette anteriorly and the anus posteriorly
internal female pelvic structures
-vagina (length, pH, cell composition)
-vagina is approximately 7 cm anterior
-composed of stratified squamous epithelium
-rugae: transverse folds in sidewalls, allows for distension
-pH: acidic because of lactobacilli
internal female pelvic structures
1. uterus
-cervix
-os
-squamocolumnar junction
-transformation zone
-squamous metaplasia
-cervix: 2.5 cm in length, 2-3 cm in diameter depending on parity
-os: opening in cervix that provides access to uterine cavity; external and internal os
-squamocolumnar junction: juncture of the squamous epithelium covering the cervical body (ectocervix) and the columnar epithelium lining the endocervix
-transformation zone: area around the squamocolumnar junction where squamous metaplasia occurs
-squamous metaplasia: process whereby columnar cells of the endocervix are replaced by mature squamous epithelium
internal female pelvic structures
-uterine body (location, length, width, composition- both externally and internally)
-located between bladder and rectum
-8 cm in length, 5 cm in width
-composed externally of thick myometrial muscles (myometrium)
-composed internally of columnar epithelium (endometrium); shed during menstruation
sections of uterus
-fundus
-isthmus
-corpus
fundus: top of uterus
isthmus: lower uterine segment
corpus: main body
uterine positions
-anteverted
-anteflexed
-retroverted
-retroflexed
-midposition
fallopian tubes
-length, ampulla function
-10 cm
-ampulla: adjacent to the ovary; receives ova at ovulation
ovaries
-size
size: 3 cm x 2 cm x 1 cm
H-P-O axis explained
- hypothalamus: releases GnRH in a pulsatile fashion
- anterior pituitary: releases FSH and LH
- ovaries: release estrogen, progesterone, androgens
3a. negative feedback loops: E + P reaching set point decreases secretion of GnRH, which leads to decreased FSH and LH
3b. positive feedback: when E reaches a peak just before ovulation, H increases secretion of GnRH, causing surge of FSH and LH (and subsequent release of mature ovum)
the three ovarian hormones
- estrogen
- progesterone
- androgens
what is the role of prostaglandins?
they regulate contractions and relaxation of smooth muscles; stimulate uterine myometrial contractions; peak levels produced by endometrium in late secretory phase (right before onset of menses)
three types of estrogen and when they are produced
- estradiol- most potent and plentiful estrogen in reproductive years
- estriol- least potent estrogen; major source during pregnancy
- estrone- major source of estrogen after menopause
where is estrogen produced in the body (4)
- ovaries
- adrenal cortex
- conversion of androgens in adipose tissue
- placentama
estrogen main functions
-maturation of reproductive organs
-development of secondary sex characteristics (breasts, hips)
-closure of long bones
-regulation of menstrual cycle (promotes proliferation of inner uterine lining in preparation for implantation)
-maternal physiologic adaptations of pregnancy
-metabolic effects on other organs
-regulated by FSH
where is progesterone produced and what is its function
ovaries, corpus luteum
-contributes to mammary gland development
-regulates menstrual cycle
-maternal physiologic adaptations in pregnancy (placental vascularization)
-regulated by LH
testosterone (an androgen) is a precursor to…
estradiol synthesis
-contributes to long bone growth, hair growth
what is sex hormone-binding globulin (SHBG)
-where is it produced
-produced by the liver
-serum protein that binds estrogens and androgens in the blood
-protein-bound hormones are able to move through general circulation to target tissues throughout body
factors that INCREASE SHBG
hyperthyroidism, pregnancy, estrogen-containing oral contraception
(increase in SHBG means a decrease in free testosterone available)
factors the decrease SHBG
obesity, hyperinsulinemia, androgens
(decrease in SHBG means there is more testosterone available)
prolactin is a….. produced in the… and its stimulates…
-hormone
-produced in anterior pituitary
-stimulates synthesis of milk proteins in mammary tissue
-stimulates epithelial growth in breast during pregnancy
-high serum prolactin inhibits GnRH (in turn, inhibiting fsh, lh, and the job of estrogen and progesterone!!)
puberty
-physical change progression
- Thelarce (breast budding)
-around age 9 - Adrenarche (pubic hair)
-from secretion of androgens - Growth Spurt Peak
-around age 12; just prior to onset of menses - Change in body shape
- Growth of underarm hair
- Menstruation/Period
-avg age is 12.5 - adult breast size
-around 17
what is considered delayed onset of puberty
secondary sexual characteristics develop later than the average age
DEFINED AS: no breast growth by age 14 or no skeletal spurt by 15
what is precocious puberty
breast or pubic hair development before age 7 in Caucasian females or 6 in AA
-evaluate to r/o congenital or neoplastic causes
how is menstrual cycle length timed? from day 1 to…
timed from day 1 of one menstrual bleed to day 1 of next menstrual bleed; average is 28 days plus or minus 2 days; bleeding 4-6 days plus or minus 2; average volume 40 cc
Ovarian cycle-defined by ovarian changes
a. follicular phase
-day 1 of menses
-estradiol and progesterone levels are low
-GnRH stimulates anterior pituitary gland to release FSH and LH
-follicles recruited, mature in ovaries, dominate follicle with most E2 receptors emerges
-drop in e2 (from other follicles undergoing atrophy) causes high FSH
-dominant follicle starts producing E2
-LH surge begins with ovulation occuring 32-44 hours later
Ovarian cycle-defined by ovarian changes
b. Ovulation
-LH surge peaks 10-12 hours before ovulation
-dominant follicle ruptures, releasing oocyte
-oocyte can be fertilized for 12-24 hours after released
Ovarian cycle-defined by ovarian changes
c. luteal phase
-begins after ovulation
-approx 14 days +/- 2 days in length
-corpus luteum forms from ruptured follicle
-CL produces high levels of progesterone peaking 7-8 days after ovulation (~day 22 of cycle)
- no pregnancy? CL regresses, E+P drop
-luteal phase ends with onset of menses
uterine cycle- defined by endometrium changes
a. proliferative phase- influenced by which hormone??
ESTROGEN = proliferative phase!
-endometrium grows/thickens
-lasts approx 10 days from end of menses to ovulation
uterine cycle- defined by endometrium changes
b. secretory phase- influenced by which hormone?
PROGESTERONE = secretory
-avg 12-16 days
-from ovulation to menses
-endometrial hypertrophy
-increased vascularity
-implantation favorable
cervical mucus
-early follicular phase
-late follicular
-at ovulation
-after ovulation
- after menses in early follicular phase- scant, thick, cloudy
- late follicular- increasing amount, thin, clear, becomes elastic
- at ovulation: abundant, thin, clear cervical mucus under influence of estrogen
- after ovulation: thick with low elasticity under influence of progesterone
what is Spinnbarkeit?
the elastic vaginal mucus around time of ovulation
how does basal body temperature change during the menstrual cycle??
-lowest in the follicular phase
-increases after ovulation under influence of progesterone (1-2 degree increase)
-remains elevated until 2-4 days before menses
