Lecture Reproductive System Part 2 (female)

• Ovaries are the female gonads
• -produce female gametes (ova)-exocrine function
• -secrete female sex hormones (Estrogen and progesterone)-endocrine function

• Accessory ducts include:
• -uterine tubes
• -uterus
• -vagina

• Internal genitalia:
• -ovaries
• -uterine tubes
• -uterus
• -vagina

• external genitalia:
• -the external sex organs
• 

• Ovarian ligament: anchors ovary medially to the uterus
• Suspensory ligament: anchors ovary laterally to the pelvic wall
• mesovarium: suspends the ovary

broad ligament: supports the uterine tubes, uterus, and vagina; also contains the suspensory ligament and the mesovarium

ovarian arteries and the ovarian branch of the uterine artery supply the blood

the ovaries are surrounded by a fibrous tinuca albuginea

• Two poorly define regions:
• -cortex: ovarian follicles
• -medulla: large blood vessels and nerves

• an Immature egg (oocyte) surrounded by
• -follicle cells (one cell layer thick)
• -granulosa cells (when more than one layer is present)

Primordial follicle: squamouslike follicle cells + oocyte

Primary follicle: cuboidal or columnat follicle cells + oocyte

Secondary follicle: contains fluid-filled space between granulosa cells; coalesces to form a central antrum

Vesicular (Graafin or tertiary) follicle: fluid filled antrum forms; follicle bulges from ovary surface

Ovulation: ejection of the oocyte from the ripening follicle

Corpus luteum develops from ruptured follicle after ovulation

• uterine (fallopian) tubes or oviducts
• uterus
• vagina

• Ampulla: distal expansion with infundibulum near ovary
• -usual site of fertilization

• ciliated fimbrae of infundibulum create current to move oocyte into uterine tube
• -oocyte is carried along by perialsis and ciliary motion
• -non ciliated cells nourish the oocyte and the sperm

isthmus: constricted region where the tube joins the uterus

• mesosalpinx: mesentery that supports the uterine tubes
• 

• body: major portion
• fundus: rounded superior region
• isthmus: narrowing inferior region
• cervix: narrow neck, or outlet; projects into the vagina

• cervial canal communicates with:
• -vagina via the external os
• -uterine body via the internal os

cervical glands secrete mucus that blocks sperm entry except during midcycle

function of the uterus is to receive, retain, and nourish a fertilized ovum

mesometrium--lateral support: portion of the broad ligament

lateral cervial (cardinal) ligament: from the  cervix and superior part of the vagina to the walls of the pelvis

uterosacrol ligaments secture the uterus to the sacrum

round ligaments bind to the anterior wall

• sacs of peritoneum exist around the uterus
• -vesicouterine pouch between the bladder and the uterus
• -rectouterine pouch between the rectum and the uterus

• 1.Perimetrum: serous layer (visceral peritoneum)
• 2. Myometrium: interlacing layers of smooth muscle which contracr during childbirth
• 3. Endometrium: mucosal lining where fertilized egg implants

• Endometrium has 2 layers:
• Stratum functionalis (functional layer)
• -changes in reponse to the ovarian hormone cycles
• -is shed during menstruation (every 28 days)
• Stratum basalis (basal layer)
• -forms new functionalis after menstruation
• -unresponsive to ovarian hormones

• uterine arteries: arise from internal iliacs
• arcuate arteries: in the myometrium
• Radial branches int he endometrium branch into:
• -spiral arteries-->stratum functionalis
• -straight arteries--> stratum basalis

• *spasms of the spiral arteries leaad to the shedding of the stratum functionalis
• 

birth canal and organ of copulation

extends between the bladder and the rectum from the cervix to the exterior

urethra embedded in the anterior wall

• 1. Fibroelastic adventitia
• 2.Smooth muscle muscularis
• 3. Stratified squamous mucosa with rugae

• -mucosa near vaginal orifice form an incomplete partition called the hymen
• -vaginal fornix: upper end of the vagina surrounding the cervix

Also called the vulva or the pudendum

• -Mons pubis: fatty area overlying pubic symphysis
• -labia majora: hair-covered, fatty skin folds
• -labia minora: skin folds lying within the labia majora
• *vestibule: recess between labia minora

• Greater vestibular glands:
• -homologous to the bulborethral glands
• -release mucus into the vestibule for lubrication

• clitoris: erectile tissue hooded by a prepuce
• -glans clitoris is the exposed portion

• perineum: diamond shaped region between the pubic arch and the coccyx
• -bordered by the ischial tuberosities laterally
• 

• modified sweat glands consisting of 15-25 lobes
• areola: pigmented skin surrounding the nipple
• suspensory ligaments: attach the breast to underlying muscle
• lobules within lobes contain glandular alveoli that produce milk

milk-->lactiferous ducts-->lactiferous sinuses-->open to the outside of the nipple

Usually arises from the epithelial cells of small ducts

• Risk factors include:
• -early onset of menstruation and late menopause
• -no pregnancies or first pregnancy late in life
• -family history of breast cancer

~10% are due to hereditary defects, including mutations to the genes BRCA1 and BRCA2

70% of women with breast cancer have no known risk factors

early detection via self-examinatino and mamography

• treatment depends on the characteristics of the lesion:
• -radiation, chemotherapy, and surgery folloed by irradiated and chemotherapy

production of the female gametes

• Begins in the fetal period
• -oogonia (2n ovarian stem cells) multiply by mitosis and store nutrients
• -primary oocytes develop in primordial follicles
• -primary oocytes begin meiosis by stall in prophase I

each month after puberty, a few primordial oocytes are activated

• one is selected each moth to resume meiosis I
• -This results in 2 haploid cells
• 1. Secondary Oocyte
• 2. First Polar Body

• The Secondary Oocyte arrest in metaphase II and is ovulated
• -if penetrated by sperm, the second oocyte completes meiosis II, yielding
• 1. ovum (the functional gamete)
• 2. second polar body
• 

• monthly series of events associated with the maturation of an egg
• -about 28 days

• 1. follicular phase: oeriod of follicle growth (days 1-14)
• 2. ovulation occurs midcycle
• 3. Luteal phase: period of corpus luteum activity (days 14-28)

• Primordial follicle becomes primary follicle
• 1. The primordial follicle is activated
• -squamous like cells become cuboidal

• 2. Follicle enlarges to become a primary follicle
• 3. Primary follicle become a secondary follicle
• -stratified epithelium (granulosa cells) form around oocyte
• -granulosa cells and oocyte guide one another's development

• 4. Secondary follicle becomes a late secondary follicle
• -connective tissue (theca folliculi) and granulosa cells cooperate to produce estrogens
• -zona pellucida forms around the oocyte
• -fluid begins to accumulate

• 5. Late secondary follicle becomes a vesicular follicle
• -antrum forms and expands to isolate the oocyte with its corona radiata on the stalk
• -vesicular follicle bulges fromt he external surface of the ovary
• -the primary oocyte completes meiosis I
• 

Ovary wall ruptures and expels the secondary oocyte with the scorona radiata

Mittleschmerz: twinge of pain sometimes felt at ovulation

1-2% of ovulation release more than one secondary oocyte, which, if fertilized is where fraternal twins come from

• Ruptured follicle collapses
• granulosa cells and internal thecal cells form corpus lutem

corpus luteum secretes progesterone and estrogen

If no pregnants, the corpus luteum degenerates into a corpus albicans in 10 days

• if pregnancy occurs, corpus luteum produces hormones until the placenta takes over at about 3 months
• 

• During childhood until puberty:
• -ovaries secrete small amounts of estrogens
• -estrogens inhibi release of GnRH

• At Puberty:
• -Leptin from adipose tissue decreases estrogen inhibition
• -GnRH, FSH, and LH are released
• -in about 4 years, an adult cyclic pattern is achieved and menarche occurs

• Day 1: GnRH--> release of FSH and LH
• -FSH and LH--> growth of several follicles and estrogen release
• -rise in estrogen levels
• *inhibit the release of FSH and LH
• *stimulate synthesis and storage of FSH and LH
• *enhance further estrogen output (positive feedback)

• Estrogen output by the vesicular follicle increases
• High estrogen levels have a position feedback effect on pituitary at midcycle
• Sudden LH surge at day 14

Completion of Meiosis I (Secondary oocyte continues on to metaphase II)

triggers ovulation

transforms ruptured follicle into corpus luteu

• Functions of the corpus luteum:
• -produces inhibin, progesterone, and estrogen
• -these hormones inhibit FSH and LH release
• -declining FSH and LH ends luteal activity and inhibits follicle development

• Days 26-28: corpus luteum degenerates and ovarian hormone levels drop sharply
• -ends the blockade of FSH and LH
• -cycle restarts
• 

Cyclical changes in the endometrium in response to ovarian hormones

• 1. Days 1-5: mestrual phase
• 2. days 6-14: proliferative (preovulatory) phase
• 3. Days 15-28: secretory (postovulatory phase) (contant 14 day length)

Ovarian hormones are at their lowest levels

gonadotropins are beginning to rise

stratum functionalis is shed and the menstrual flow begins

estrogen levels prompt generation of new functional layer and increased synthesis of progesterone receptors in theendometrium

glands enlarge and spiral arteries increase in number

• progesterone levels prompt
• -further development of endometrium
• -glandular secretion of glycogen
• -formation of cervical mucus plug
• 

• -corpus luteum degenerates
• -progesterone levels fall
• -spiral arteries kink and spasm
• -endometrial cells begin to die
• -spiral arteries constrict again, then relax and open wide
• -rush of blood fragments weakened capillary beds and the functional layer sloughs

Promotes oogenesis and the follicle growth in the ovary

exert anabolic effects on the female reproductive tract

support the rapid but short-lived growth at puberty

• Induce secondary sex characteristics:
• -growth of the breasts
• -increased deposit of subcutaneous fat (hips and breasts)
• -widening and lightening of the pelvis

• metabolic effects:
• -maintain low total blood cholesterol and high HDL levels
• -facilitates calcium uptake

progesterone works with estrogen to establish and regulate the uterine cycle

• effects of placental progesterone during pregnancy
• -inhibits uterine motility
• -helps prepare the breasts to lactation

initiated by touch and psychological stimuli

The clitoris, vaginal mucosa, and breasts engorge with blood

vestibular gland secretions lubricate the vestibule

orgasm is accompanied by muscle tension, increase in pulse rate and bp, and rythmic contractions of the uterus

females do not have a refractory period after orgasma nd can experience multiple orgams

orgasm is not essential for conception