physio - E4: reproductive

fetus development progress

fetus development progress

zygote -> embryo -> fetus -> birth

what is TDF?

testis determining factor
- if present = male
- absent = female

does the sperm or ovum decide the sex of the fetus?

sperm
(bc its XY! females will only provide X to the fetus)

female vs male differentiation ducts

F = mullerian ducts (uterus, uterine tubes)

M = wolffian ducts (epididymides, vas def, ejaculatory duct)

what is MIF (mullerian inhibition factor)?

inhibit mullerian ducts! MIF is for MALES!!!!!!

how is testosterone cycled

testosterone -> 5-apha reductase -> DHT -> liver -> bile/urine


**remember that androgens (steroids/thyroid) affect dna/rna

male secondary sex characteristics

later growth spurt, muscle, penis, testis growth

male body hair is stim by _____ from adrenal glad at puberty

androgens (testosterone)

6 other androgen effects on males

1. baldness
2. skin thickness
3. acne (↑ sebum)
4. protein/muscle dev
5. bone deposition
6. RBC prod
7. ↑ prostate size (benign prostatic hyperplasia)

male: LH vs FSH
- what cell do they come from
- what do they secrete

LH
- leydig cells
- TESTOSTERONE = neg feedback for LH

FSH
- sertoli cells in seminiferous tubules
- INHIBIN = neg feedback for FSH (inhibits spermatogenesis)

sperm maturation location

seminiferous tubules

epididymis role

sperm maturation & storage
(remain 5 days in female after sex; 120milli sperm made/day)

Sperm pathway (to epididymis)

Seminiferous tubules -> rete testis -> efferent ducts -> epididymis

ejaculation tract

epididymus -> vas def -> ejaculatory duct -> urethra

what 4 things is semen composed of

1. sperm

2. seminal fluid = fructose (sperm snack), fibrinogen, prostaglandins
- largest part!

3. prostate fluid = citric acid, Ca, zinc, coag proteins, profibrinogen

4. bulbourethral gland = galactose & mucus
- ↑ sperm motility

which components does an erection require?

vascular, nerve, psychological, hormonal (testosterone) component

which part of penis receives blood flow in erection

corpus cavernosa

how does the PNS affect erections

has NO = vasodilation

emission vs ejaculation

emission = semen into urethra
ejaculation = expulsion of semen from urethra

emission and ejaculation are under what control?

SNS - pudendal nerve

point & shoot

point - erection = PNS
shoot - ejaculation = SNS

female gonads (ovaries) are the cite of ___ & ___ production

oocyte & sex steroids (estrogen/progesterone)

what "catches" oocyte after ovulation

fimbriae

female site of fertilization

fallopian tubes - ampulla

layers of uterus

endometrium = inner layer, embryo implants
myometrium = middle layer, contracts during birthing
perimetrium = outer conn tiss
cervix = bottom region of uterus

2 female sex hormones - where do they come from

OVARIES:
estrogen = egg (non-preg)
progesterone = corpus luteum (preg)

when are FSH & LH elevated for females

first 6 months of life, declines until puberty

females: FSH vs LH

FSH = follicle stimulator
LH = ovulation (egg ejected into fallop. tube)

female reproductive system pathway

hypo -> GnRH -> anterior pit -> FSH & LH -> ovary -> estrogen, progesterone, inhibin

female: inhibin role

inhibits FSH

ovarian follicle secretes...

estradiol

granulosa cells secrete...

inhibin

corpus luteum secretes

progesterone & estradiol

ovarian vs uterine cycle: main hormones

ovarian - FSH & LH
uterine - estrogen & progesterone

proliferative vs secretory phase of uterine (menstrual) cycle

proliferative = endometrium gets fluffy to accept egg
secretory = peak fluffy phase

average ovarian cycle

28 days

primary components of ovarian cycle

- GnRH
- FSH & LH
- estrogen & progesterone

↑ estrogen (estradiol) = ____ LH

↑

how many oocytes released from primary follicle

ONE

(its called the Primary Oocyte)

# of oocytes throughout life

birth = 2 mill
puberty = 400,000
400 ovulated total throughout life

in response to FSH, primary oocytes will produce layers of

granulosa cells
(some develop secondary follicles)

3 phases of ovarian cycle

1. follicular phase
2. ovulation
3. luteal phase

follicular phase

FSH -> 1° follicle -> 2° follicle -> Gaafian follicle -> estradiol

LH Surge = increased estradiol = hypo to release GnRH = LH release = ovulation!

what happens to Graffian follicle after LH surge

rupture = releasing oocyte!

luteal phase

ruptured follice -> corpus luteum -> estradiol & progesterone -> will inhibit FSH/LH

3 phases of menstrual cycle

1. menstrual phase
2. proliferation phase
3. secretory phase

uterine cycle - proliferation phase

- occurs while ovary is in the follicular phase

- estradiol = endometrium growth & increases progesterone receptors

uterine - secretory phase

- occurs while ovaries are in the luteal phase

- progesterone -> more growth of endometrium

uterine - menstrual phase

fall of estradiol & progesterone when corpus luteum degenerates = endometrium = sloughed

how many sperm make it into fallopian tube?

300 mill enter, 100 make it!!!

what stimulates Ca2+ and the release of the acrosomal enzymes

1. acrosome cap (sperm)
2. zona pellucida cells (oocyte)

role of acrosomal enzymes

allows sperm to digest zona pellucida on its way into oocyte

(sperm + oocyte = baby!)

on the ___ day after fertilization, the blastocyst implants into endometrium

6th

(7-10th day, blastocyst is buried)

while implantation occurs, the blastocyst releases...

hCG

hCG role

keeps corpus luteum alive to release estradiol & progesterone = inhibit FSH/LH = inhibit ovulation = inhibit menstruation

what happens on the 10th week (2nd trimester) after blastocyst is implanted?

hCG declines & the PLACENTA takes over hormone prod

KNOW THAT ITS THE 10TH WEEK

umbilical arteries vs veins

umbilical arteries = fetus -> placenta

umbilical veins = placenta -> fetus

does maternal and fecal blood mix?

NO- they're separated by 2 CELL LAYERS

what are the only things that will diffuse between mother & fetus?

O2, CO2, alcohol

how much weight should the mother gain in preg

25-35lbs!!

how is metabolism affected during preg?

increases = hot flashes

maternal changes - nutrition

need increased...
- iron
- vit D & Ca
- vit K

maternal changes - blood flow

increased...
- CO!!
- aldosterone/fluid retention
- 1-2 extra liters of blood at delivery

maternal changes - respiration

increased...
- ventilation = O2
- sensitivity to CO2
FETUS PRESSING UP ON DIAPHRAGM

how is blood coag affected for preg mother

increased! to protect mom from hemorrhage
- more likely for DVT & pulm embolism tho :(

how is GFR affected for preg mother

increased!
- glucose will increase in urine
- gestational diabetes = at risk of dev T2DM later in life

are preg women constipated?

yes = bc of progesterone!!!!

length of gestation

40 weeks (measured from first day of LKMP)

phases of labor

0. uterus is quiescent (dormant) bc...
corpus luteum = progesterone + relaxin

1. activation of uterus
- Braxton-Hicks contration = false labor
- oxytocin & prostaglandins

2. dramatic stage
- contractions & dilation of cervix

3. the return
- uterus returns to normal size with assistance from myometrium

initiation of labor pathway

fetal androgen prod -> placental CRH secretion -> pit gland ACTH secretion

once labor is initiated....

prostaglandins = contrations
oxytocin = expulsive stage of labor (Ferguson reflex)

milk flow

lobules -> lactiferous ducts -> nipple

breast milk composed of

1. fats - trig
2. proteins - casein & lactalbumin
3. CHO - lactose

Yellow fluid produced during the first 3 days after labor

colostrum (high protein & antibodies)

what stimmulates milk prod vs milk flow

milk prod = prolactin
milk flow = oxytocin

suckling relfex inhibits...

GnRH = ↓ FSH/LH and ↓ menstrual cycle in breast feeding mothers

mothers who don't breastfeed will resume menstrual cycle ____ months after birth

2-4

how does the contraceptive pill (OCP) work...

contains estradiol & progesterone = acts like luteal phase = inhibits GnRH = no FSH/LH = no egg production/ovulation

- endometrium still proliferates
- menstruation still occurs (placebo pills)

methods of contraception...

natural contraception = abstinence

barrier = condoms, caps

intrauterine devices (IUDs) = prevent blastocyst implantation