II. Male Reproductive Organs -
  A. Testes
    1. structures
      a. lobules (2-300 per teste)
      b. seminiforous tubules (2-3 per lobule)
        i. Leydig cells (LH triggers testosterone secretion)
        ii. sertoli cells (FSH triggers activation to support spermatogonia and secrete inhibin & ABP)
        iii. spermatogonia (FSH triggers spermatogenesis in seminiforous tubules)
      c. straight tubules
      d. ciliated rete testis
      e. epididymis - spermatozoa maturation & storage
  B. Spermatogenesis - begins at puberty, continues through life
    1. meiosis
    2. spermatogonia - diploid
    3. spermatocyte - diploid
    4. spermatid - haploid
    5. spermatozoan - mature haploid gamete
    6. hormonal control of production
      a. hormones
        i. gonadotropin releasing hormone (GnRH) - triggers FSH & LH release from ant. pit.
        ii. follicle stimulating hormone (FSH) - triggers spematogenesis, inhibin & ABP secretion
        iii. lutenizing hormone (LH) - stimulates testosterone secretion
        iv. testosterone - induces secondary male characteristics, stimulates late spermatogenesis steps
        v. androgen binding protein (ABP) - binds testosterone, concentrates it in semin. tubules
        vi. inhibin - inhibits FSH secretion (part of spermatogenesis negative feedback)
      b. duration & rate
  C. Other reproductive structures
    1. vas deferens - muscular walls, propels spermatozoa towards urethra
    2. seminal vesicle - contributes 60% seminal volume, alkaline carbo-rich
    3. prostate gland - 25% volume, fibrolysin
    4. cowpers gland - mucus, alkaline

III. Female Reproductive Organs -
  A. Oogenesis - begins at third month as fetus, ends at fertilization
    1. oogonia - diploid
    2. primary oocyte - diploid, ~200,000 total inside primary follicles
    3. secondary oocyte - begin development at puberty (20-25/month), dominant one released at ovulation
    4. polar body -
    5. onset
      a. timing
      b. GnRH, FSH & LH
    6. Ovarian cycle (28 days total)
      a. early menstruation (begins day 1)
        i. 20-25  2^o oocytes produced in ovarian follicles
      b. preovulatory (follicular) stage (days 6 to 13 though variable)
        i. Graafian follicle produced (one dominant 2^o oocyte)
        ii. high estrogen prod. by follicles ~~> increases GnRH & LH secretion (“LH Surge”)
        iii. most variable stage
      c. ovulation (day 14)
        i. rupture of Graafian follicle
        ii. release of  2^o oocyte
        iii. max. fertil. time within 2 days
        iv. corpus luteum produced
     d. post ovulatory (luteal) stage
         i. corpus luteum produces more progesterone ~~> inhibits GnRH & LH; prepares endometrium
        ii. if fertilization occurs - hCG secretion from embryo maintains corpus luteum
        iii. if NO fertilization - no hCG ~~> corpus luteum degenerates into corpus albicans
          aa. less progesterone (PG) & estrogen (EST) produced ~~> causes menstruation
          bb. less  PG, EST, and inhibin   ~~> increase GnRH, FSH, LH for new cycle start
    6. Uterine (menstrual) cycle
      a. menstruation begins cycle (day 1)
        i. decreased estrogen & progesterone cause endometrium to lose blood supply and slough off
      b. preovulatory (proliferative) stage (days 6 to 13 though variable)
        i. increased estrogen from follicles induce endometrium growth, thickening
      c. postovulatory (secretory) stage (days 15 to28)
        i. progesterone from corpus luteum prepares endometrium for implantation

IV. Fertilization -
  A. Events
    1. fert. usually in uterine tube
    2. 12-24hrs postovulation
  B. Structures
    1. 2^o oocyte
      a. corona radiata
      b. zona pellucida
      c. polar bodies
    2. spermatozoa
      a. acrosome
    3. zygote
    4. cleavages
    5. morula
    6. blastocyst
      a. trophoblast
      b. inner cell mass
      c. hCG production
  C. Implantation
    1. endometrium
    2. trophoblast