Female Reproductive System

Female Genital System Parts

• Ovaries

• Uterine Tubes

• Uterus

• Vagina

• External Organs

• Mammary Glands (not technically part, but related)

Uterus Anatomy

• Fundus

• Left and Right Fallopian Tubes

• Ovaries

• Body

• Cervix (meaning neck)

• Vaginal Canal

Functions of the Female Genital System

Ovaries:

• produce secondary oocytes (egg cells)

• produce hormones:

  • Estrogen

  • Progesterone

  • Inhibin

  • Relaxin

• uterine tubes transport secondary oocyte to (Fill otu)

• uterus is the site of implementation (attachment) of fertilization

  • will attach to wall and develop into fetus

  • contracts to expel baby during birth

• vagina receives penis during intercourse, and serves as passageway for childbirth

  • very distensible canal

• mammary glands synthesize, secrete, eject milk for nourishment of newborn

Ovaries

• female gonads (homologs of testis in males)

• a pair of glands

• similar in size to unshelled almonds

  • but will decrease in size after menopause

• produce gametes (secondary oocytes)

• produces hormones progesterone and estrogen

Ovary Ligaments

ovary is held in place by these ligaments

Broad Ligament:

• fold of the peritoneum

• attached to the peritoneal cavity

  • but not inside the cavity

• attached to ovaries by the mesovarium

Ovarian Ligament:

• anchors ovaries to the uterus

Suspensory Ligament:

• attaches ovaries to pelvic wall

Ovary Histology

Ovarian Mesothelium:

• outer layer, surface epithelium

• low cuboidal to squamous

Tunica Albuginea:

• whitish capsule

• dense irregular connective tissue

• covers the ovaries

Ovarian Cortex:

• deep to tunica albuginea

• composed of ovarian follicles + stroma cells + dense irregular connective tissue

Ovarian Medulla:

• deep to cortex

• connective tissue

• BVs + lymphatics + nerves

Ovarian Follicles

• composed of oocyte + all surrounding cells

• egg cells are not observed by themselves in ovary; have surrounding

Follicular Cells:

• a single layer of surrounding cell

• forms early in development

Granulosa Cells:

• forms later in development

• has several layers of surrounding cells

Tertiary Ovarian Follicle:

• aka vesicular or Graafian follicle

• large, fluid filled follicle

• ready to rupture and release oocyte

• every menstrual cycle, only one follicle ruptures

Corpus Luteum:

• luteum = yellow, corpus = body

• tissue that forms after follicle ruptures

• physiologically active: produces estrogen, progesterone, relaxin, inhibin

• supplies initial hormones for survival of implanted embryo

Corus Albicans:

• albicans = white

• degraded corpus luteum after it is no longer needed

• no activity

Oogenesis

• germ cells migrate from yolk sac to ovaries in fetal development

• within ovaries, germ cells become oogonia

• oogonia divide to form millions of germ cells

• some become primary oocytes

  • they pause at meiosis I

  • will not continue until after puberty

• each oocyte is encases in a layer of flat follicular cells (ovarian follicle)

• ovarian cortex consists of collagen fibers and stromal cells

• at birth, each ovary holds 200,000 to 2,000,000 primary ooctyes

  • no more will be made

• by puberty, only about 40,000 remain

• throughout the reproductive years, only about 400 mature

• monthly, about 20 primary oocytes progress to secondary oocytes

• typically only 1 survives for ovulation

  • when one ruptures, the other follicles will just degenerate

Oogenesis 2

• starts with 2n=46 1^o oocyte that divides, resulting in two n=23 cells

  • one is a large 2^o oocyte, the other is a small 1st polar body that may divide

• pauses at meiosis I

• second division only occurs if 2^o oocyte is fertilized

  • results in one large n=23 ovum (egg) and one small n=23 2nd polar body

Overall:

• oogenesis results in one large fertilized egg (zygote), and possibly three small polar bodies (if the 1st one divides)

Ovarian Follicles Again?

• they consist of oocytes in various stages of development + surrounding cells

  • oocyte = immature ova

• surrounding cells secrete estrogens for purpose of

  • growth and repair of uterine lining

  • regulation of monthly female cycle

  • female sexual/secondary sexual characteristics

  • maintenance of bones and muscles

Menopause:

• physiological “death” of ovary

• loss of function

• hence menopause can lead to loss of bone mass

  • can lead to fractures or microfractures

Follicular Development

Primordial Follicle:

• single layer of squamous follicular cells around oocyte

Primary Follicle:

• also called pre-antral follicle

• develops from stimulation of primordial follicles by FSH and LH

• layer of cuboidal follicular cells

• and layers of cuboidal and columnar granulosa cells around the oocyte

• theca folliculi develops

  • organized group of stromal cells that surround basement membrane

Zona Pellucida:

• clear glycoprotein layerbetween oocyte and granulosa cells

• formed as primary ovarian follicle grows

Corona Radiata:?

• innermost layer of

Secondary Follicle:

• theca folliculi divides into:

  • theca interna: highly vascularized tissue; secretes some androgens

  • theca externa: stromal cells + collagen

• Antrum:

  • cavity found in the middle of secondary follicle

  • follicular fluid builds up in antrum

Mature Follicle:

• also called Graafian follicle

• large, fluid-filled

• ready to rupture and expel secondary oocyte

• occurs on monthyl basis

• some other note I didn’t catch

Corpus Luteum:

• ruptures graafian follicle

• secretes:

  • progesterone

  • estrogens

  • relaxin

  • inhibin

Corpus Albicans:

• white scar tissue left after corpus luteum dies

Uterine Tubes

• also called fallopian tubes or oviducts

• normally have two, extend laterally from uterus

• narrow, 4-inch tubes

Functions:

• site of fertilization

• transport route for sperm

• transport secondary oocytes

  • ciliated surface epithelium sweep the oocyte

• transport fertilized ova from ovaries to uterus

• not stuck to ovary; terminates in close approximation to them instead

  • oocyte will have to enter the tube

Uterine Tube Anatomy

Infundibulum:

• funnel shaped portion of tube

• located near ovary; but is open to pelvic activity

Fimbriae:

• fingerlike projections at end of infundibulum

• attached to lateral end of ovary

Ampulla:

• widest and longest portion of tube

• other notes

Isthmus:

• narrowest part of uterine tube

• joins uterus and tube

Processes in Uterine Tube

• Fimbriae sweep secondary oocyte into uterine tube

• Cillia and peristalsis guide secondary oocyte from peritoneal cavity to uterine tube

• sperm will meet oocyte in ampulla

  • fertilization can occur 24 hours after ovulation

  • estimate: calendar contraception uses range of 3 days to make sure

• zygote reaches uterus roughly 7 days after ovulation

• unfertilized secondary oocytes disintegrate

Uterine Tube Histology

Mucosa:

• innermost layer

• contains ciliated columnar epithelium

  • acts as conveyer belt; moves oocyte along

Muscularis:

• middle layer

• d

Serosa:

• d

Uterus

• also called the womb

• site of implementation of fertilized ovum

• site of development of fetus

• site of labor

• source of menstrual flow

Weight Gain in Pregnancy

• gains around 13-15 kg

  • Baby: 7.5 pounds

  • Placenta: 1.5 pounds

  • Amniotic Fluid: 2 pounds

  • Uterine Enlargement: 2 pounds

  • Maternal Breast Tissue: 2 pounds

  • Maternal Blood Volume: 4 pounds

  • Fluids in Maternal Tissue: 4 pounds

  • Maternal Fat Stores: 7 pounds

Uterus Anatomy

• 3 × 2 × 1 inches, especially small when not pregnant

Fundus:

• dome shaped superior portion

Body:

• tapering central portion (wider at base, then gets narrower)

  • Isthmus: located between body and cervix

  • Uterine Cavity: interior cavity of the body

Cervix:

• interior narrow portion

  • Cervical Canal: interior of cervix, opens into v

Position of Uterus:

Normal Position Based on Tilting

Anteverted:

• tilts forward towards bladder

Retroverted:

• tilts backward into spine

Vertical: 

• no tilting, upright position

Normal Position Based on Fundus:

• Anteflexed: fundus bends forward

• Retroflexed: fundus bends backwards

Breech Pregnancy

• normally baby is expelled head first

• in breech pregnancy, baby is expelled feet first

• with improper technique, this can kill the baby

Uterine Ligaments

Broad Ligaments:

• attach uterus to pelvic cavity either side

Uterosacral Ligaments:

• connect uterus to sacrum

Cardinal Ligaments:

• lateral cervical ligaments

• d

D

Uterus Histology

Endometrium:

• innermost portion

• has two layers:

  • Stratum Functionalis: lines uterine cavity; sloughs off during menstruation

    • very vascular structure

    • is more superficial

  • Stratum Basalis: gives rise to new s. functionalis after each menstruation

Myometrium:

• thickest layer

• middle layer

• consists of three layers of smooth muscle

• is thickest in the fundus, thinnest in the cervix

  • contraction is stronger in the fundus, weaker in the cervix, causes baby to move towards cervix

Perimetrium:

• outermost layer

• anteriorly, covers bladder and forms a shallow pouch (vesicouterine pouch)

• posteriorly, covers rectum and forms recto-uterine pouch (pouch of Douglas)

• note: covers does not mean attached; a mass can still form in between

  • potential sites of fluid buildup

  • can be sign of malignancy

Uterine Prolapse

• downward displacement of uterus

• may result from weakening of supporting ligaments and pelvic musculature

First Degree:

• mild

• cervix remains within the vagina

Second Degree:

• marked

• cervix protrudes to the exterior through the vagina

Third Degree:

• complete

• entire uterus is outside of vagina 

Hysterectomy

surgical removal of uterus:

• Partial: body of uterus is removed; cervix is left

• Complete/Total: both body and cervix is removed

• Radical: removal of body, cervix, and uterine tubes; possibly the ovaries and other supporting structures

  • may be performed due to malignancy

• Total Abdominal Hysterectomy with Bilateral Salpingo-Oophorectomy: surgery through abdomen; remove everything

Ectopic Pregnancy

• ectopic = abnormal location

• embryo has implanted in abnormal position

  • common site: isthmus or elsewhere in uterine tube

• not compatible with life

• no available surgery to move baby to correct place

• life-threatening to mother: rupture can cause hemorrhage

• treated with teratogenic drugs or surgery

• prone:

  • those with previous infections (ex: STIs, Pelvic Inflammatory Diseases/PIDs)

  • may cause damage and removal of cilia to move oocyte forward

Vagina

• shared passageway for menstrual flow, birth, and penis

• 4-inch long fibromuscular organ ending at cervix

• lines between urinary bladder and rectum

• orifice partially closed with membrane called hymen

  • hymen tears with sexual intercourse, trauma, or strenuous physical activity

  • in some patients, may be abnormally closed; causes blockage of menstruation → pelvic infection + abdominal pain (imperforate hymen)

• Fornix:

  • edge where vagina connects into cervix

  • some contraceptive devices can be put here (ex: diaphragm) 

Vulva

• also called pudendum

• external geneteilia 

Components:

• Mons Pubis:

  • adipose tissue, covered by skin and pubic hair

  • protects the pubic symphysis

• Labia Majora:

  • 2 longitudinal folds of skin

  • hairy, contain adipose tissue, sebaceous glands, sweat gland

  • homolog of scrotum

• Labia Minora:

  • 2 smaller folds of skin

  • devoid of hair and fat; few sweat glands, many oil glands

  • homolog of spongy urethra (penile part of urethra)

• Clitoris

  • homolog of penis

  • small cylindrical mass of erectile tissue and nerves

  • anterior junction of labia minora

  • stimulated to cause orgasm

  • Glans: exposed portion

  • Prepuce: skin formed at point where d

Vestibule:

• region between labia minora

• homologus to membranous urethra

• contains hymen, vaginal orifice, urethral orifice

Skene’s Glands:

• paraurethral glands

• mucus-secreting glands in urethra wall

• homologus to prostate

Bartholin’s Glands:

• greater vestibular glands

• mucus-secreting, provides lubrication during arousal

• homologous to bulbourethral glands

Bulb of Vestibule:

• 2 elongated masses of erectile tissue

• deep to labia on either side of vaginal orifice

• homologus to corpus spongiosum

Fourchette:

• transverse fold of skin

• passes between posterior terminations of labia minora

Perineum

• diamond shaped area medial to thighs and buttocks

Divided into:

• Urogenital Triangle:

  • D

• Anal Triangle:

  • d