Fetal Hormones & Sexual Differentiation

Reproductive Development

• Obstetric Nursing originates from "obstetric," meaning "midwife."
• Midwives care for clients during prandial periods.
• Gonads are reproductive organs: testes in males and ovaries in females.
• Testes produce sperm carrying X and Y chromosomes.
• Ovaries produce eggs carrying XX chromosomes, determining gender.

Sex Determination

• Gender develops around the 5th week of intrauterine life with primitive gonadal tissue.
• Two ducts are present: Mesonephric Duct (male) and Paramesonephric Duct (female).

Role of Testosterone

• Between the 7th and 8th week, high testosterone levels from primitive testes cause the mesonephric duct to develop into male reproductive organs.
• The paramesonephric duct regresses due to high testosterone.
• Absence of testosterone by the 10th week causes gonadal tissues to become ovaries, and the paramesonephric duct develops into female reproductive organs.
• Testosterone presence or absence determines sex.

Early Development Summary

• Primitive gonadal tissues are present at 5 weeks of intrauterine life.
• Primitive testes develop during the 7th-8th week, producing small amounts of testosterone.
• High or low testosterone determines the development of mesonephric or paramesonephric ducts.
• Ovaries produce egg cells with XX chromosomes.
• Testes produce sperm cells with X or Y chromosomes.
• XX sperm fertilizing an egg results in a female (XX) baby.
• Y sperm fertilizing an egg results in a male (XY) baby.
• Mesonephric ducts form male organs, and paramesonephric ducts form female organs if testosterone is low.

Pubertal Development (General)

• Puberty starts around age 9, ends around age 17.
• Secondary sex changes begin between ages 9-17 for both sexes, with average ages varying by sex.
• Growth spurts occur earlier in girls (9–12) and later in boys (12–14).

Hormonal Roles

• In females, the adrenal cortex and ovaries use the hypothalamus as a master clock.
• The hypothalamus triggers the adrenal cortex to produce hormones.
• Ovaries produce estrogen and progesterone.
• In males, adrenal cortex stimulates the testes to produce testosterone.

Female Sexual Development

• Acceleration in linear growth (growth spurt) marks initial development.
• Transverse diameter of the pelvis increases, followed by breast development (thelarche).
• Pubic hair grows (adrenarche), then menstruation begins (menarche), and axillary hair develops.
• Ovulation follows after the other named developments.
• Increase in vaginal secretions also occurs.
• Earliest sign of female secondary sex characteristics is increase in height, or accelerated linear growth.
• Thelarche is the female secondary sign of sex characteristic.
• Pubic hair appears earlier than axillary hair.

Male Sexual Development

• Weight increases, then shoulders broaden.
• Testes grow, followed by face, axillary, and pubic hair, and the voice changes.
• Penile growth then height increase (second to last) and spermatogenesis complete the development.
• Seminal fluid production begins in males around ages 12–14, while sperm production occurs later.

Reproductive Anatomy

• Male and female reproductive anatomy has external and internal structures.

Male External Structures

• The penis contains glands covered by skin known as the prepuce.
• The scrotum hangs from the body and holds the testicles.
• Testicles are outside the body because sperm cells are heat sensitive.
• Scrotal temperature is 1 degree Fahrenheit lower than body temperature.
• An erect penis averages 4 to 5 inches in length.
• The urethra in the penis's tip functions for urination and semen passage.
• The male urethra averages 7 inches in length.

Male Internal Structures

• The testes produce testosterone and are responsible for spermatogenesis in seminiferous tubules.
• The epididymis serves as storage for sperm maturation.
• The vas deferens connects the seminal vesicle and epididymis.
• The seminal vesicle, prostate gland, and Cowper's gland produce seminal fluid.
• 5% of seminal fluid from epididymis, 30% from seminal vesicle, 60% from prostate, 5% from Cowper's gland.

Fluids and Semen

• Sperm travels from the vas deferens to the ampulla.
• Seminal fluid is produced to lubricate the sperm in the ejaculatory duct.
• Sperm route is: testes, then epididymis (5% fluid), then vas deferens, then ampulla, then seminal vesicle (30% fluid), then prostate (60% fluid), then Cowper’s (5% fluid).

Ejaculation and Semen

• Sperm cells are alkaline to survive vaginal acidity.
• Cowper's and prostate glands produce alkaline secretions.
• Forceful ejaculation ensures sperm doesn't stay in the acidic vaginal canal.
• Sperm reaches the cervix in 90 seconds and fallopian tubes in 5 minutes.
• Testosterone and testes are male sex hormones and glands, respectively.
• Vasectomy is surgical sterilization that involves ligating and cutting the vas deferens, and sperm cells die after maturation.

Surgical Sterilization

• After vasectomy, sperm may remain in the vas deferens causing pregnancy, so condoms should be used for 2 months.
• Sperm cells mature for 64 days; testing sperm count ensures sterility.
• Vasectomy doesn't stop erection/spermatogenesis but prevents sperm ejaculation.
• It also doesn't protect from STDs.

Semen Analysis

• Average semen: 3-5 mL, at least 20M sperm/mL, 150M sperm/mL
• Oligospermia: <20M sperm/mL, Aspermia: zero sperm.
• Clomid helps increase sperm production and fertility.
• Average ejaculation: 400M sperm.
• Sperm lifespan: 3-5 days, pH 7-8 alkaline.

Sperm Characteristics

• 30% normal shape/size (so every ejaculation 200M are alive).
• 50% motility (are activley moving).
• 50% Viability

Female External Anatomy

• Mons pubis protects the symphysis pubis.
• Labia majora/minora and the clitoris are present, with the clitoris providing sexual stimulus.
• The vestibule contains urethral meatus and vaginal orifice.
• The female urethra is shorter than the male urethra.
• Clitoris visible for catheterization.
• The fourchette joins labia minora and majora.
• Paraurethral glands and Bartholin's glands are present, with the latter lubricating the vagina.
• Episiotomy is a perineal incision to widen the birth space.
• Mediolateral episiotomy is better than midline.
• Nerve endings are avoided by cutting during contractions.

Female Internal Anatomy

• Size: 3x2x1 inches, pear shaped location
• Location: between bladder and rectum.
• Position: anteflexion, anteverted, retroverted, retroflexion, flexion (abnormal), The uterus assumes a retroverted position during the 2nd trimester.

Uterine Position

• Anteflexion exhibits uterus fundus is leaning sharply forward.
• Discomfort of pregnancy experienced as urinary frequency experienced by pregnant women.
• A pregnant woman is 2 ½ mos pregnant is the uterus already enlarging and anteverted, causing bladder compression.
• This urinary frequency in the 3rd mos. of trimester disappears in 2nd trimester when the uterus position is retroverted.

Uterine Functions

• Implantation site with endometrium; and houses/nourishes products of conception
• Aids in the delivery (promoting contractions).
• Outer perimetrium, middle myometrium and the inner endometrium.
• The uterus as a whole has 4 parts: Fundus, Corpus, Isthmus, Cervix
• Site in fundus, location with the thickest myometrium that gives it the capacity for a strong uterine contraction while downward baby pushes.

Cervix and Ovaries

• Internal os effaces; pregnancy = cervical canal turns into operculum (thickened), which softens because of high estrogen levels.
• External os widens, estrogen makes the cervix soft through Goodell's sign,.
• Purplish/Blueish = Chadwick sign
• Internal os measured by % in delivery and external os by "cm".
• Endometrium best site of implantation in upper segment - posterior, supplied by uterine arteries
• Implamation happen in endometrium, not myometrium, future pregnancy

3 Probable Signs of Pregnancy:

• Chadwicks sign (purplish/blueish color)
• Goodell's sign (softness of cervix)
• Hegar's sign (softening of cervix); GS and HS are the same in function.
• Soft-Non pregnant and earlobe. Late and early = nose tip and earlobe
• Thickned Cervicle mucus(Operculum); acidic vaginal canal with acidity
• Supports the uterus.

Ligaments of the Uterus and Location

• Broad keep the tubes and uterus.
• Round ligament (in midde = important).
• Uterosacral floor ligament/pelvic support(low), allows a retroverted position
• Cardinal (cardinal is not call cardinal, it is not important: stable: cordnal to fundus in 2nd trimester: round
• Uterine nerve is Sensory with the ability to affect motor contractions:
• Epidural affects senosry (with painless delivery.
• 1 Degree differemce between body and S temperature: Sperm=cold

The Fallopian Tubes (Ovaries)

• Pair of tubular Organs; transports ovum once fertilized (w/c
• Is outer thrid) has taken site
• Ampulla allows fertilization, common of ectopic pregnancy
• Fimbriae cath egg -1st day after last mensuration is best time to get tubal ligation 3.4 stay fertilized and Pro (ges): enlargeuterus Estrogen: contractuters Function: produce progesterone and estrogen with epothelium divisions of 3 division.

The Breast

• Mammary Gland in pectoralis muscles, produces milk, storage of milk
• Mammary gland needs stimulus of: Lactin which goes to pituatry and oxytoin to contraract. The best after action of baby because contration remains firm: This will also prevent post bleeding period.

Pelvis

• Support for reproductive and pelivis ogran; has 2 divisions = false and tru
• True= starts at pubis bone : gylnecold, anthropoid, androird(mal), plat(flat) for pregnancy
• Inlet transverse is bigger A then P..Oulter trans smaller, A and P is big Head need to rotate to deliver Baby Mechanism: Defelx, Flex rotate Fetus need pressure and amniotic to move: ballottement.

Ischial Tuberosity

• Sit and weight: Ishical: spine (patay): If pressuring the pelvis baby will get: (t) or not.
• Stationo Zero= pressure to deliver ba; it to low but head not engange, by Bounncine attemp. If head was alwasys engage: its down 5 positve. Ischa Sp is important for delivery. If IE(internal exam) = negative for station: babay may have balllottement Pressure = 3.4 station positive for dialation and contactions

Attitude

• Felx tagala yuko four region of smallness of head
• Suturs to cranial point to space.
• Diamind space called Fotenal Fetal to vagina
• Cephalic, breech and Trasver
• Baby in C head but depend, will still not cause cervical head

Featal Lies and main manament of monapus

Longitudinal, transverse if uterus and parallel to head. This comes down at the same time: E and Pro: but Pro needs to be higher

Pre Menstral Cycle

• GonadoTropins; Ovaries less sensitve, therefore lower E will release

Mamagement of E and Health

• E replacement, hot flash, vagina
• Prevet mood and ostersioosis.. you get younger. cant with fam history breast cancer. after last P Calcium(vitD) will hel renal stones. Regular exercise hel[

Menstration

• Discharge blood from uterus; normal aver= 60cc, heavy; palos Menstration perios only three to fire 7 days, cycle 23 to maxim 40 day: ave 28 day First to 17 , safe:

OVARY

Cycle ovulation: release 2 , and you get pregnant; or if not 8-10 day 3rd: Hormonal, estogen(first), prog(latter), day of cycle If the day cycle does not exist ever month, irriregular, this can cause for infertile cycle. Days are fertile day, not, Note; Longest you do not go more them 35 day; You can do 30 so u set it urself. E is 1st then APG; APG(2), then ovary.. High level

• 4 dates: then P and ovulation hel for pregnancy If your have not had intercourse a B can be very in heat cycle..then its pro and prog is ready to high 7-7 32

Ovarian Fallopian

3d: Low E, stimulation :Est will help 20+ to stim uterus. 1st day menses. 13day: Will releas HRF:stim E then the ovary will increase

Female ovulation

• 2 weeks long then. Corpus lumun. then help contract uterine.
• 3-5ml liquid of sperm, 1ml =5-10m sperms; .4 ml (1 tsp = 1 ml) are active
• Test in lab before Follpoian has fllopain tubule and out is fimbre; which in turn in inter.. If outter = preg outside

Q to ask

7days : pro help fert, and enlarge Es: help contr. E; 8-10 preg get test 4 in total are regulare for ferti If 8/9 = low E = get preggo.

• 2 main layer of ovum to find radita and zona 4= Then ZONA Is tough: made gly 12 35

Explore the hormonal mechanisms driving sexual differentiation during fetal development. Learn about the role of testosterone in developing male reproductive organs and the timeline for its influence. Understand the alternative developmental pathways in the absence of sufficient testosterone.