fertility vphy made from slides

clinical infertility

The inability to achieve pregnancy after one year of regular, unprotected intercourse or after 6 months if the woman is older than 35

y chromosome contains?

SRY gene which encodes a transcription factor which partially directs the formation of MALE sex organs

Androgens include?

testosterone (T) and DHT

Estrogens include?

estradiol (E2) and estrone

cholesterol

precursor for all steroid hormones

aromatase

converts androgens into estrogens

5-a-reductase

converts test to DHT

DAX1

nuclear receptor protein, transcriptional repressor

SOX9

SRY-related HMG-box genes

XY male hormone cascade

SRY upregulates SOX9 and SF1 which bind to promoter of AMH; inhibits development of female reproductive tract-Mullerian DUcts

XX Female hormone cascade

DAX1-suppresses gene expression of SOX9 and SF1, no AMH; enables development of female reproductive tract-mullerian ducts

internal sexual differentiation time period

begins at 7-10 weeks of a 38 week gestational period

female at sexually indifferent stage

no AMH SRY test, Mullerian ducts develop into uterine tubes and uterus, wolffian ducts degenerate

male at sexually indifferent stage

has AMH SRY TEST, Wolffian ducts develop into epididymis and vas deferens, Mullerian ducts degen

XX male

male despite having two x bc one of x chromosomes contains SRY Gene due to translocation

XY female

morphologically female despite having XY chromosomes bc Y chromosome is missing SRY due to translocation

Male external sex differentiation

Genital tubercle-glans of penis
labioscrotal fold-scrotum
presence of androgen DHT=masculinized external genitalia
each step catalyzed by enzymes encoded by specific genes

female external sex differentiation

Genital tubercle-clitoris
labioscrotal fold-labia majora
absence of androgen DHT=feminized external genitalia
each step catalyzed by enzymes encoded by specific genes

spermatogenesis

begins at puberty
two meiotic divisions of one spermatogonium yield four spermatids-four mature sperm
continuous, gradual decline

time to produce ejaculated sperm?

42-76 days

sperm concentrations

>20million/mL of ejaculate
less than 15 million is infertility

daily sperm production

150 to 275 million spermatozoa

Anterior Pituitary Gonadotropins

LH stimulates Leydig cells
FSH stimulates Sertoli cells

Luteinizing hormone (LH)

leydig cells
produce test during development and inc during puberty
Test essential for spermatogenesis

Follicle Stimulating Hormone (FSH)

stimulates sperm maturation
sertoli cells
regulate sperm development
produce inhibin and androgen-binding protein (ABP)
(test bound to ABP is les lipophilic and cant diffuse out of tubule lumen)
important to keep high concentration of test in lumen for spermatogenesis

test effects before birth

masculinizes the repro tract, precursor for DHT-descent of testes into the scrotum

DHT and test bind the?

Androgen receptor (AR) but DHT has a higher affinity for AR

test effects on sex tissues after birth

Essential for spermatogenesis and oogenesis
• Promotes growth and maturation of the reproductive system at puberty
• Precursor for all estrogens
• Maintains the reproductive tract in adulthood

NES/T

male hormone contraceptive where nesterone suppresses gonadotropins LH/FSH

Condoms

87% effectiveness for preventing pregnancy

Vasectomy

minimally invasive outpatient procedures, sometimes reversible suture back together vas deferens

effectiveness >99%

Spermicide

common chemical used= Nonoxynol-9
creams, gels, included on some barrier methods
degrades acrosome
inhibits sperm motility

Copper IUD

intrauterine device
copper:inhibits sperm motility and acrosomal enzyme activation

All IUDS: in uterine cavity, have strings extend past cervix to check insertion

Oogenesis

1-2 million primary oocytes arrested at meiosis at birth
300k primary oocytes by puberty
400-500 ovulate over lifetime (30-45yrs)
fertilization completes meiosis (secondary ooctyes nucleus fuses with haploid sperm nucleus

Menstrual cycle

last avg 28 days
starts first day of menstruation
ovarian cycle and uterine cycle

Early follicular phase ovarian cycle

days 1-7
formation of estrogens in the follicle depend on thecal and granulosa cells
estrogen negatively feedback on GnRH, FSH, LH

Thecal cells

synthesize androgen

Granulosa cells

convert androgen to estrogen via aromatase

Late follicular phase to ovulation

days 8-14
inhibin causes neg feedback on FSH
right before ovulation, high levels of estrogen and rising levels of progesterone enhance pituitary responsiveness to GnRH= pos feeback of estrogen stimulates LH surge (ovulation occurs 24hrs after LH surge).body temp inc

Early to Mid-Luteal phase (ovarian cycle)

days 15-23
corpus luteum formed from remaining follicular cells after ovulation
Estrogen, progesterone(dominant), and inhibin exert strong neg feedback on GnRH, FSH and LH (prevents ovaries from developing more follicles and releasing oocytes)

Late Luteal Phase (ovarian cycle)

24-28 days
without pregn-corpus luteum degenerates
estrogen and progesterone levels drop triggering menses

Menstrual (uterine cycle)

days 1-5
lack of ovarian hormones, endometrial shedding, menstrual flow

Proliferative (uterine cycle)

estrogen-endometrial building and inc progesterone receptors
days 6-14

Secretory (uterine cycle)

days 15-28
prepares for possible implantation
-inhibits myometrium contractions
-angiogenesis
-nutrient secretion
-cervical plug

phase 1 of Human sexual arousal

excitement-parasympathetic
inc blood flow to genitals
vag lubrication swelling of labia

testes swell scrotum tightens

phase 2 of sexual arousal

plateau-sympathetic
excitement grows
inc in HR, BP, RR and muscle tension

phase 3 of sexual arousal

orgasm-sympathetic
-climactic short phase of sexual response
-sensation of orgasms doesnt differ across sexes

phase 4 of sexual arousal

-body slowly return to unexcited state
-refractory period occurs during male resolution phase (cant become aroused for a period of time)

Erection

parasympathetic response
mediated by NO

Ejaculation (male)

sympathetic response
may/not accompany orgasm
release from storage in vas deferens/epididymis

adult fertility

reproductive years 18-44
fluctuates with menstrual
stays high for sperm-producing individuals
gonadotropin levels LH>FSH

climacterium fertility

age 45-55
menstruation more sporadic
dec/changes in libido
dec in estrogen levels=hormone replacement therpy replaces ovarian sources of estrogen

senescence

age 56+

cessation of menstrual cycle
dec in sperm count
gonadotropin levels highest (FSH>LH)

secondary oocyte only capable of being fertilized for_post ovulation

12-24 hrs

capacitation of sperm

ejaculated sperms are infertile until in the female repro tract for 7-10hrs

site of fertilization

uterine/fallopian tubes

cleavage of zygote

36hr after fertilization

morula=16 cell stage

50-60hrs after fertilization

blastocyst

4 days after fertilization
the inner cell mass forms the embryo then feturs after week 8
the trophoblasts form fetal placenta

implantation in uterine wall

day 8-9 after fertilization

hormone changes during preg

estrogen and progesterone cont inc (corpus luteum during first 8 weeks)

hCG secreted by trophoblast cells as implantation starts(peak at 8wks), allows for persistence of corpus luteum stimulating it to secrete estrogen and progesterone

prevents further menstrual cycles

pre-pubescent

0-7yrs
infertile
gonadotropin levels lowest
FSH>LH

puberty (8-14)

physiologically capable of conceiving
onset of pulsatile GnRH
gonadotropin levels inc and reverse
LH>FSH

Hormonal birth control

progestin, estrogin

pills, shot, IUD

prevents ovulation

birth control pills

either estrogen and progestin or progestin only
taken daily to stop release of oocyte from the follicle (prevent ovulation)
thins uterine lining

thickens cervical mucus

levonorgestrel

class of progestin
binds to progesterone and androgen receptors
slows GnRH release, suppresses LH surge
most effective <24hrs, can take up to 3 days

Ulipristal acetate

requires prescription
binds to progesterone receptor
suppresses LH surge, delays ovulation even if LH surge already occured
most effective <24 hrs can take up to 5 days

birth control shot

contains progestin

stops ovulation, thickens cervical mucus, thins uterine lining

implant birth control

steady dose of progestin
prevents ovulation
thickens cervical mucus
thins uterine lining

hormonal IUD

releases progestin
thicken cervical mucus
thins uterine lining

bilateral tubal ligation

uterine tubes obstructed
not reversible

Bilateral salpingectomy

remove uterine tubes
not reversible