Saladin Ch. 28 - FEMALE REPRODUCTIVE SYSTEM
FUNCTIONS
	Produce gametes
	Site for fertilization
	Provide nourishment and protection for offspring

I.  REPRODUCTIVE ANATOMY
     A.  OVARIES – from endodermal tissue
	Produce secondary oocytes during oogenesis and hormones
	Held by 3 ligaments – broad [part of parietal peritoneum], ovarian [to uterus] and 
suspensory [to pelvic wall]
	HISTOLOGY
Germinal epithelium of simple squamous to cuboidal epithelium – on 
outer surface
		Tunica albuginea – deep to germinal layer
		Cortex – contains ovarian follicles and dense CT
		Medulla – loose CT, vessels, nerves
		Ovarian follicle = oocyte + surrounding follicle cells - In cortex [see figure 28.2, 				p. 1067]
			Follicle epithelial layers progressively become more numerous, and fluid 
is secreted into space with oocyte
			Graafian [mature] follicle – large, fluid filled – contains secondary oocyte 
ready for ovulation
				Secretes estrogens
			Corpus luteum – remnants of follicle after ovulation
				Secretes progesterone, estrogens, relaxin and inhibin
				Degenerates into corpus albicans
		Ligaments - ovarian, suspensory & mesovarian
     B.  GENITALIA
	1. Uterine [fallopian] tubes - Transport channels for ova
	Usually site of fertilization  zygote reaches uterus in about 7 days
		Layers – mucosa, smooth muscles and serosa
			Mucosa – continuous with vagina and uterine
		Path for infectious agents to enter peritoneal cavity [ex. PID]
		Infundibulum – portion closest to ovary
		Fimbriae – finger-like projections from infundibulum
			Sweep- push ova into tube
     C.  Uterus
Pathway for sperm, Site of menstruation, Site of implantation, Site of fetal 
development
	Parts
		Fundus
		Body – uterine cavity
		Isthmus
		Cervix – cervical canal
		External os	
	Secretory cells of the cervical mucosa lining produce cervical mucus
	
	3 layers – Uterine Wall
Perimetrium – part of visceral peritoneum
		Myometrium – 3 layers of smooth muscles – stimulated by oxytocin 
during labor]
		Endometrium – highly vascularized
			Simple ciliated columnar epithelium + secretory cells
			2 layers:
			  	Stratum functionalis – closest to uterine cavity – shed 
  		during menstruation
				Stratum basalis – permanent layer which repeatedly gives 
		rise to stratum functionalis
Blood supply – uterine arteries  arcuate arteries  radial arteries  straight arterioles 	or spiral arteries
Straight arterioles terminate in s. basalis and supply materials needed to regenerate s. functionalis
		Spiral arterioles penetrate into s. functionalis and change markedly during 
menstrual cycle
	Held in place by 4 ligaments [broad, uterosacral, cardinal, round]
     D.  Vagina [birth canal]
	Functions- Passage for menstrual flow, Passage for sperm, Passage for childbirth
	Tubular fibromuscular organ with mucus membrane of stratified squamous 
epithelium.
Mucus has large amounts of glycogen which decomposes to produce acids.  The low pH retards microbial growth, but is harmful to sperm
	Muscularis – smooth muscle, rugae stimulate penis, highly stretchable.
     E.  Vulva – external female genitalia
	Mons pubis = skin + adipose cushion of pubic symphysis
	Labia majora – 2 folds of skin with sebaceous and sudoriferous glands
	Labia minora – 2 folds medial to majora – contain mostly sebaceous gland
	Clitoris – small mass of erectile tissue and nerves with prepuce and a glans 
[analogous to penis]
Vestibule – cleft between labia minora – contains vaginal orifice, urethral 
orifice and duct openings.
Paraurethral glands [equiv. To prostate] secrete mucus
Greater vestibular glands [equiv. To Cowper’s] produce mucus for lubrication
     F.  Mammary glands
	Modified sudoriferous glands which produce milk
	Areola – pigmented area around nipple – contains modified oil glands
	Function – lactation – control – prolactin [synthesis] and oxytocin [ejection]		15-20 lobes separated by adipose tissue
	Subdivided into lobules with clusters of alveoli = milk secreting glands
	Produce milk passes to lactiferous ducts to nipple.
     G.  Breast cancer
	12% or more of population
	Begin in mammary ducts - metastasize via axillary nodes
	2 genes that cause it have been identified - BRCA 1 and 2.
	Most is non-hereditary
	Treatment - lumpectomy, simple or radical mastectomy, radiation and chemo

II.  PUBERTY & MENOPAUSE
     A.  PUBERTY
	USA - 9 - 10 onset
	GnRH --> FSH & LH
		FSH --> follicles --> estrogens, progesterone & inhibin
	Estrogens "feminize" body
	Phases:
		thelarche - breast development
		pubarche - hair, etc.
		menarche - beginning of menstruation - related to nutrition and body fat status
			ovulation doesn't usually start until a year later.
	Progesterone - prepares uterus for [possible pregnancy
	Inhibin suppresses FSH
     B.  MENOPAUSE - when cycling ceases	
	begins when egg count drops below 1000
	organs atrophy
	hot flashes - sudden dilation of cutaneous vessels
	Hormone replacement therapy - progesterone and/or low dose estrogen - have risks.

III.  OOGENESIS  THE SEXUAL CYCLE
A.  OOGENESIS
	Primordial germ cell from yolk sac migrates to ovary during development 
	Mitosis  a primary oocyte [2N]; Primary oocyte enters meiosis I, stops [primary 			follicle]
		Atresia - At birth may have up to 2 million - by puberty have about 400,000
	At puberty LH levels rise, oocyte completes meiosis I = Secondary oocyte + polar body.
	In monthly cycles, one or more secondary oocytes enter meiosis II, stop at metaphase II
	If fertilization occurs  completes meiosis II = ovum
	Ovum nucleus fuses with sperm  zygote; if no fertilization, ovum degenerates.
B.  SEXUAL CYCLE - 28 days on average
	Control: hypothalamus --> pituitary --> ovaries --> uterus
	Ovarian cycle – 2 phases - follicular & luteal		
		Follicular Phase – preantral - before birth, & antral phases
			Primordial follicle - develops 12-16 wks gestation - oocyte in early 					meiosis + single layer of follicular cells
			Primary follicle - pre-birth - follicular cells thicken and ad layers -- > zona 				pellucida [glycoprotein gel]
			Secondary antral follicle -  develops from primary to Graafian – several 					develop each month.  
			Dominant follicle - The one that wins the race to develop first undergoes 					ovulation – expulsion from Graafian follicle into body cavity			The time BEFORE ovulation is the pre-ovulatory period 
			Ovulation - rupture of follicle - [omit mechanism]
		The Luteal phase then begins - the corpus luteum develops from the remnants of 				the Graafian follicle & secretes Es & P [increases 10X]
			No pregnancy --> stops secretion and becomes corpus albicans.

HORMONAL CONTROL OF SEXUAL CYCLE
[controlled by GnRH from hypothalamus]

				HYPOTHALAMUS
				      [GnRH]

Stimulates

				ANTERIOR PITUITARY

				LH                             FSH

Decreased
Blood estrogen,
Progesterone

		Stimulates further follicle                             Development of 
		Maturation into Graafian                               ovarian follicle
		Follicle

		Stimulates ovulation                                    Estrogens

		Production of 
		Corpus luteum
		      Stimulates estrogens,
		      Progesterone, inhibin
		      Relaxin

	Corpus albicans – stops
	Producing estrogens, progesterone

Initiates another
Menstrual cycle	
     C.  MENSTRUAL CYCLE – build up, breakdown and disposal of endometrium monthly.
	1. General: 4 phases involve hormonal changes [brain, pituitary, ovaries, uterus], cyclic    
                changes in breast and cervical tissue - Average cycle – 28 days [24-35 range]
	2. Proliferative phase - days 6-14
	Estrogen stimulates replacement of stratum functionalis via mitosis in stratum 				basalis  increases endometrium thickness;
		Estrogen also stimulates formation of progesterone receptors 	
	3.  Secretory phase – days 15-28
		Progesterone stimulates increased proliferation of endometrial 
glands and stimulates release of glycogen from them.  Progesterone also stimulates vascularization and thickening of the stratum functionalis and an increase in tissue fluid
	4. Premenstrual phase	 
If fertilization does not occur corpus luteum degenerates to Corpus albicans and 			get low Progesterone and Estrogen levels constriction of spiral arterioles 		 ischemic phase  necrosis, degeneration
	5. Menstrual phase – first 1-5 days
	Cells supplied by spiral arterioles slough off – results in total loss of 
	stratum functionalis [50-150 mL blood, tissue and fluid]

IV. FEMALE SEXUAL RESPONSE – see Figure 28.18

V.  PREGNANCY & CHILDBIRTH
     A. PRENATAL DEVELOPMENT
	Blastocyst – hollow ball – 2 wks
	Embryo – 2-8 wks
	Fetus – wk 9 on
	Neonate – first 6 wks after birth
     B. HORMONES OF PREGNANCY
	1. HCG – from blastocyst & placenta – stimulates growth of corpus luteum to continue 		    progesterone & estrogen production
	2. Estrogens -  most effects from estrodiol.  Increases 30X during pregnancy – 1st 12 wks 
               from CL, then placenta; stimulates fetal & maternal tissue growth, breast growth, etc.
	3. Progesterone – CL, then placenta. With Estrogen suppresses pituitary – no additional 	 
                follicle development,, suppresses contractions, keeps endometrium intact
	See Table 28.2 for other hormones of pregnancy
     C. ADJUSTMENTS TO PREGNANCY – OMIT
     D. CHILDBIRTH
	1. Vertex position – most common – move into at 7th mo.
	2. Uterine contractility – Braxton Hicks contractions – “twitches” of uterus
	3. Labor contractions = onset of birth = parturition
		Increases in ES overrides P, to allow contractions of the uterine muscles
		Oxytocin stimulates contractions – in concert with prostaglandins produced by 				fetal membranes, 
		Relaxin increases the flexibility of the pubic symphysis
		Stretching of smooth muscles also promotes onset of contractions [ fetal 					“dancing”]
	4. 3 stages for true labor
		Stage of Dilation - onset of contractions, rupture of amniotic sac, dilation 
of cervix – up to 10 cm
		Stage of Expulsion - from point of maximal cervical dilation until the 
baby's body exits through the vagina – may require episiotomy
		Placental stage - time required after expulsion of the infant until the 
placenta is expelled.
      E. Puerperium – post delivery – 6 wks – body is returning to “normal”
	1. uterine involution
	2. lactation – nursing for median age 2.8 years world wide.

VI. LACTATION
     A. Mammaries – develop under stimulation of estrogen and other hormones.  Many ducts.
     B. Colostrum & milk
	1. colostrums = low fat milk 1-3 days, has antibodies that get into circulation
	2. milk – prolactin stimulates synthesis – antagonized by steroids – hence no production 
                DURING pregnancy; hormone surge with each feeding – stimulates production for 
                next feeding
	3. few women become pregnant while nursing, but SOME do – inhibits GnRH
	4. postpartum cycles are usually anovulatory for several months
     C. Milk ejection – oxytocin – stimulus is suckling

VII. CONTRACEPTION – review methods pages 1096 – 1098.