1. 28-1 Endocrinology of reproduction Reproductive System

2. 28-2 Anatomy of Male Reproductive System Testes Series of ducts –Epididymides –Ductus deferentia –Urethra Accessory glands –Seminal vesicles –Prostate gland –Bulbourethral glands Supporting structures –Scrotum 2 chambered sac that contains testes Dartos and cremaster muscles help regulate temperature –Penis Perineum –Diamond-shaped areas between thighs

3. 28-3 Male Pelvis

4. 28-4 Testes Glands –Exocrine –Endocrine Compartments divided by septa –Seminiferous tubules Empty into rete testis Empties into efferent ductules –Interstitial or Leydig cells Descent –Pass from abdominal cavity through inguinal canal to scrotum Cryptorchidism –Failure of of one or both of testes to descend into scrotum –Prevents normal sperm development

5. 28-5 Histology of Testis

6. 28-6 Descent of Testes

7. 28-7 Sperm Cell Development Spermatozoa produced in seminiferous tubules Spermatogonia divide (mitosis) to form primary spermatocytes Primary spermatocytes (first division of meiosis) divide to form secondary spermatocytes Secondary spermatocytes (second division of meiosis) divide to form spermatids Spermatids develop an acrosome and flagellum Sertoli cells nourish sperm cells and form a blood-testis barrier and produce hormones

8. 28-8 Spermatogenesis

9. 28-9 Meiosis

10. 28-10 Ducts Epididymis –Site of sperm cell maturation Ductus deferens or vas deferens –Passes from epididymis into abdominal cavity Ejaculatory duct –Joining of ductus deferens and seminal vesicle Urethra –Extends from urinary bladder to distal end of penis –Passageway for urine and male reproductive fluids –3 parts Prostatic urethra Membranous urethra Spongy or penile urethra

11. 28-11 Male Reproductive Structures

12. 28-12 Penis Three columns of erectile tissue that engorge with blood –Corpora cavernosa (2) –Corpus spongiosum (1) Glans penis –Prepuce or foreskin covers Circumcision: Surgical removal External urethra orifice

13. 28-13 Penis

14. 28-14 Accessory Glands Seminal vesicles –Empty into ejaculatory duct –Produce about 60% of semen Prostate gland –Produces about 30% of semen Bulbourethral glands –Contribute about 5% to semen Secretions –Semen Composite of sperm cells and secretions –Emission Discharge of semen into prostatic urethra –Ejaculation Forceful expulsion of semen from urethra

15. 28-15 Regulation of Sex Hormone Secretion Hypothalamus releases –GnRH or LHRH which stimulates LH or ICSH to produce testosterone FSH to stimulate sperm cell formation Inhibin inhibits FSH secretion from anterior pituitary

16. 28-16 Puberty and Testosterone Puberty –Age at which individuals become capable of sexual reproduction Before puberty small amounts of testosterone inhibit GnRH release During puberty testosterone does not completely suppress GnRH release, resulting in increased FSH,LH, and testosterone Testosterone –Produced by interstitial cells, adrenal cortex and sustentacular cells –Causes development of male sex organs in embryo, stimulates descent of testes, causes enlargement of genitals and necessary for sperm cell formation

17. 28-17 Male Sexual Behavior and Male Sex Act Male sexual behavior –Testosterone required to initiate and maintain Male sex act –Complex series of reflexes that result in erection of penis, secretion of mucus into urethra, emission, ejaculation –Sensations result in orgasm associated with ejaculation and then resolution

18. 28-18 Neural Control of Erection Stimulation –Tactile or psychological –Parasympathetic Erection due to vasodilation of blood vessels –Sympathetic Causes erection, emission, ejaculation Erectile Dysfunction

19. 28-19 Anatomy of Female Reproductive System Female reproductive organs –Ovaries –Uterine tubes –Uterus –Vagina –External genital organs –Mammary glands

20. 28-20 Female Pelvis

21. 28-21 Uterus, Vagina, Uterine Tubes, Ovaries and Supporting Ligaments

22. 28-22 Ovary Histology

23. 28-23 Maturation of Follicle and Oocyte

24. 28-24 Maturation and Fertilization of Oocyte

25. 28-25 Follicle and Oocyte Development Oogenesis is the production of a secondary oocyte in ovaries Oogonia are cells from which oocytes develop Primary oocytes are surround by granulosa cells and called a primordial follicle Primordial follicle becomes a primary follicle when oocyte enlarges and cells change Primary follicle becomes secondary follicle and enlarges to form mature or graafian follicle –Usually only one is ovulated, others degenerate Primary oocyte completes first meiotic division to produce secondary oocyte and a polar body Secondary oocyte begins second meiotic division, which stops in metaphase II

26. 28-26 Ovulation and Follicle Fate Ovulation –Follicle swells and ruptures, secondary oocyte is released from ovary –Second meiotic division completed when secondary oocyte unites with sperm cell to form zygote Fate of the follicle –Graafian follicle become corpus luteum –If fertilization occurs, corpus luteum persists –If no fertilization, becomes corpus albicans

27. 28-27 Uterine Tubes and Uterus Uterine or fallopian tubes or oviducts –Open directly into peritoneal cavity to receive oocyte from ovary –Transport oocyte or zygote from ovary to uterus Uterus –Parts: Body, isthmus, cervix –Composed of 3 layers Perimetrium: Serous membrane Myometrium: Smooth muscle Endometrium: Mucous membrane

28. 28-28 Vagina and Perineum Vagina –Female organ of copulation –Allows menstrual flow and childbirth –Hymen covers the vaginal opening or orifice Perineum –Divided into two triangles Urogenital: Contains the external genitalia Anal triangle Clinical perineum – Region between vagina and anus –Episiotomy: Incision to prevent tearing during childbirth

29. 28-29 Female External Genitalia Vulva or pudendum or external female genitalia –Vestibule: Space Labia minora: Form borders on sides Clitoris: Erectile structure –Corpora cavernosa –Corpora spongiosa –Labia majora Unite to form mons pubis

30. 28-30 Female Perineum

31. 28-31 Mammary Glands Organs of milk production located within mammae or breasts –Consist of glandular lobes and adipose tissue –Cooper’s ligaments support the breasts

32. 28-32 Puberty and Menstrual Cycle Puberty –Begins with menarche or first episode of menstrual bleeding –Begins when GnRH levels increase Menstrual Cycle –About 28 days long –Phases Menses Proliferative phase Secretory phase Menses –Amenorrhea: Absence of a menstrual cycle –Menopause: Cessation of menstrual cycles

33. 28-33 Menstrual Cycle

34. 28-34 Hormone Regulation during Menstrual Cycle

35. 28-35 Female Sexual Behavior and Sex Act Female sexual behavior –Depends on hormones Androgens and steroids –Depends on psychological factors Female sex act –Parasympathetic stimulation Blood engorgement in clitoris and around vaginal opening Erect nipples Mucouslike fluid extruded into vagina and through wall –Orgasm not necessary for fertilization to occur

36. 28-36 Female Fertility and Pregnancy Female fertility –Sperm ejaculated into vagina during copulation and transported through cervix and uterine tubes to ampulla –Sperm cells undergo capacitation Pregnancy –Oocyte can be fertilized up to 24 hours after ovulation –Sperm cells can be viable for up to 6 days in female tract –Ectopic pregnancy: Implantation occurs anywhere other than uterine cavity

37. 28-37 Sperm Cell Movement

38. 28-38 Changes in Hormones During Pregnancy

39. 28-39 Control of Pregnancy Behavioral methods –Abstinence –Coitus interruptus –Rhythm method Barrier methods –Condom Male and female –Diaphragm –Cervical cap –Spermicidal agents Lactation Chemical methods –Oral contraceptives –Injections as Depo- Provera –Implants –Morning-after pills Surgical methods –Vasectomy –Tubal ligation –Abortions

40. 28-40 Effects of Aging Male –Decrease in size and weight of testes –Decrease in sperm production –Prostate gland enlarges and increase in cancer –Impotence is age- related –Decrease in sexual activity Female –Menopause –Decrease in size of uterus and vaginal wall thins –Age related increase in breast, uterine, ovarian cancer