Major organs of female reproductive system:

1
Major organs of female reproductive system

• Brain - releases GnRH
• Pituitary gland - secretes LH and FSH
• Ovary - produces eggs and sex hormones (estrogen
  and progesterone)

2
Ovary

• located in pelvis
• has central core (medulla) and outer layer
  (cortex)
  
• germ cells stored in cortex
• highly vascular

3
Statistics regarding female germ cells

• Germ cells cannot regenerate after birth
• Most (99) never ovulate but become atretic and
  die
  
• At birth, 500,000 eggs / ovary
• At puberty, 83,000 eggs / ovary
• At 50 years, fewer than 1,000
• Only 400 ever ovulate

4
Female germ cells (egg, oocyte)

• Provides half of genetic material of new
  individual
  
• Supplies food and biochemical machinery for early
  development
  
• Surrounded in ovary by follicle
• Cell layers of follicle secrete factors which
  nurture, induce maturation of egg

5
Follicular development
Primordial follicle
Primary follicle
Secondary follicle
Tertiary follicle
Graafian follicle
6
Small group discussions Mitosis vs. Meiosis

• What are homologous chromosomes? Sister
  chromatids?
  
• How many chromosomal replications occur during
  mitosis? Meiosis? How many cell divisions occur
  in each?
  
• How do chromosomes line up on mitotic / meiotic
  spindle?
  
• Whats a polar body?

7
Oogenesis

• At birth, primordial oocytes are arrested just
  prior to their first meiotic division
  
• Meiosis doesnt resume until just before
  ovulation (due to LH surge)
  
• First meiotic division produces 2 germ cells of
  unequal size (secondary oocyte and polar body)
  
• Second reduction division doesnt take place
  until sperm penetrates the egg

8
Role of LH in follicle development

• stimulates androgen production by thecal cells
• causes rupture of Graafian follicle during LH
  surge
  
• LH surge stimulates first meiotic division
• causes transformation of follicle to corpus luteum

9
Role of FSH in follicle development

• stimulates growth of follicles by acting on
  granulosa cells
  
• causes granulosa cell proliferation, secretion of
  factors necessary for maturation of egg

10
Oviducts

• Site of fertilization transports embryo to
  uterus
  
• Internal lining has folds, ciliated cells
• Estrogen causes mucus secretion, ciliary beating,
  smooth muscle contraction
  
• Rarely, ectopic or tubal pregnancies occur
• Tied off during tubal ligation

11
Uterus

• size and shape of an inverted pear
• located between bladder and rectum
• consists of three layers
• perimetrium (external surface)
• myometrium (thick layer of smooth muscle)
• endometrium (internal lining)
• Endometriosis abnormal growth of endometrium

12
Cervix

• cap on uterus
• mucus glands produce plug
• Viscosity of mucus changes in response to
  estrogen
  
• pap smear
• Human papilloma virus
• cervical cancer is 8th most frequent
  cancer-caused fatality in women

13
Vagina

• copulatory organ and birth canal
• capable of stretching (facilitates childbirth and
  intercourse)
  
• environment is acidic (lactobacilli lactic
  acid)
  
• prevents yeast infections
• acidic environment is hostile to sperm

14
External genitals (vulva)

• mons pubis
• labia majora
• labia minora
• clitoris
• urinary and reproductive systems remain separate
• in early years, vagina is covered by a ring of
  tissue called the hymen

15
Female sexual response

• Erectile tissue found in clitoris and labia
• Sexual arousal vasocongestion
• Due to muscle contraction restricting flow
  through dorsal vein of clitoris
  
• orgasm relief of vasocongestion, muscular
  contractions within the vagina and uterus

16
Female Circumcision

• Type I FC clitoral hood is pricked or removed
• Type II FC clitoris and most or all of the labia
  minora are removed
  
• Type III FC (pharonic circumcision,
  infibulation) clitoris, labia minora and most of
  labia majora removed vulva wound is stitched
  closed