2. The Reproductive System
Chapter 19
The Reproductive System

3. Introduction
Reproduction: process by which genetic material is passed from one generation to the next
Meiosis produces sex cells
Sperm from male and egg from female join to form zygote
Zygote develops into embryo
Embryo develops into fetus

4. The Male Reproductive System

5. Introduction Testes: produce sperm and male sex hormones
Accessory glands: produce secretions
Accessory organs: scrotum
Penis: transporting and supporting structure

6. Introduction (cont’d.)

7. The Scrotum Outpouching of abdominal wall Supports the testes
Divided internally by a septum
Scrotal sac elevates and descends

8. The Testes Tunica albuginea: capsule covering with lobules
Convoluted seminiferous tubules
Spermatogenesis

9. The Testes (cont’d.) Spermatogenesis
Spermatogonia > primary spermatocytes > secondary spermatocytes > spermatids > spermatozoa
Sertoli cells: supply sperm cells with nutrients
Interstitial cells of Leydig: produce testosterone

10. The Testes (cont’d.)

11. The Anatomy of the Spermatozoa
Three hundred million produced daily
Anatomy
Head: contains genetic material and acrosome
Acrosome has enzymes that aid sperm in penetrating covering of ovum
Middle piece: contains mitochondria
Tail: propels sperm

12. The Anatomy of the Spermatozoa (cont’d.)
Anatomy of a sperm cell

13. The Functions of Testosterone
Controls development, growth, and maintenance of male sex organs
Stimulates muscle buildup and bone development
Causes sperm maturation
Causes thyroid cartilage enlargement
Produces body hair patterns

14. The Ducts of the System Seminiferous tubules: transport sperm cells
Rete testis: network of ducts
Ductus epididymis: site of sperm cell maturation
Epididymis located on posterior border of testis

15. The Ducts of the System (cont’d.)
Vas deferens: straightened portion of epididymis
Enclosed in spermatic duct
Ejaculatory duct: ejects spermatozoa into urethra
Urethra: terminal duct
Prostatic urethra, cavernous urethra, urethral orifice

16. The Accessory Glands Seminal vesicles: produce viscous part of semen
Prostate gland: produces fluid part of semen
Bulbourethral glands: produce mucus

17. Semen Mixture of sperm cells and secretions
Provides energy to the sperm via fructose
Neutralizes acidity of vagina
Acts as a transport medium
Contains enzymes that activate sperm
Average volume is 2.5 to 6 mL
Seminalplasmin: destroys certain bacteria

18. The Penis Delivers spermatozoa to female reproductive tract
Glans penis: end of the shaft
Prepuce: loose skin covering glans penis
Circumcision: removal of prepuce

19. The Penis (cont’d.) Contains masses of spongy tissue with sinuses
Sinuses fill with blood resulting in erection
Compress veins so blood is retained
Help penis penetrate vagina
During ejaculation, sphincter at base of urinary bladder is closed

20. Animation – Male Reproductive System
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21. Animation – Sperm Formation
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22. The Female Reproductive System

23. Introduction Primary sex organs Accessory organs
Ovaries
Accessory organs
Uterine tubes, uterus, vagina, external genitalia
Accessory glands: produce mucus

24. Introduction (cont’d.)

25. The Ovaries Held in position by ligaments
Covered by germinal epithelium
Tunica albuginea: cortex contains ovarian follicles
Ovarian follicles: eggs in various developmental stages
Primary follicle: contains oocyte

26. The Ovaries (cont’d.)

27. The Ovaries (cont’d.) Oogenesis
Begins in developing female fetus (700,000 produced)
Puberty: ovarian cycle begins
Primary oocyte: first meiotic division
Mature egg: second meiotic division

28. The Uterine or Fallopian Tubes
Transport ova to the uterus
Infundibulum: funnel-shaped end with fimbriae
Cilia sweep an ovum into uterine tube
Egg moved by peristalsis toward uterus
Fertilization occurs in upper third of tube

29. The Uterus Site of menstruation, egg implantation and labor
Pear shaped
Uterine cavity: interior of the body
Cervical canal: interior of the cervix
Uterine wall: endometrium, myometrium, perimetrium

30. The Menstrual Cycle Menstrual phase
Endometrial lining shed along with blood and mucus
Ovarian follicles begin development
Preovulatory or proliferative phase
Secondary follicle matures into graafian follicle
Ovulation is rupturing of graafian follicle

31. The Menstrual Cycle (cont’d.)
Postovulatory or secretory phase
Corpus luteum develops
Secretes estrogen and progesterone
If fertilization and implantation do not occur
Corpus luteum degenerates and new cycle starts
If fertilization and implantation occur
Corpus luteum maintained for four months

32. Animation - Ovulation
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33. The Functions of Estrogen
Development of female secondary sex characteristics
Breast development, pubic hair, fat deposits, widening of the pelvic bone
Enlargement of:
Uterine tubes, uterus, vagina, external genitalia

34. The Vagina Passageway for menstrual flow Receptacle for the penis
Lower portion of birth canal
Fornix: surrounds vaginal attachment to cervix

35. The External Genitalia of the Female
Vulva: external genitalia
Labia: majora and minora
Clitoris: erectile tissue
Vestibule: vaginal and urethral orifices
Glands: Skene’s and Bartholin’s

36. The External Genitalia of the Female (cont’d.)

37. The Perineum

38. The Perineum (cont’d.)
Diamond-shaped region at inferior end of trunk between buttocks and thighs
Divided into:
Anterior urogenital triangle containing external genitalia
Posterior anal triangle containing anus

39. The Anatomy and Function of the Mammary Glands

40. The Anatomy and Function of the Mammary Glands (cont’d.)
Produce milk in females
Contain 15 to 20 lobes with lobules
Lobules contain milk-secreting cells
Milk is conveyed through series of tubules
Areola: circular pigmented area around nipple

41. The Anatomy and Function of the Mammary Glands (cont’d.)

42. Pregnancy and Embryonic Development

43. Pregnancy and Embryonic Development (cont’d.)
Egg fertilization hours after ovulation
Zygote: fertilized egg
Moves down uterine tube into uterus
Blastula
Zygote embeds in endometrium, placenta develops

44. Pregnancy and Embryonic Development (cont’d.)
Primary germ layers
Ectoderm: skin and nervous system
Mesoderm: muscles and bones
Endoderm: linings of organs and glands
Amnion: fluid-filled sac
Attached to embryo by umbilical cord
Parturition: childbirth

45. Animation – Female Reproductive System
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46. Summary Discussed the organs of the male reproductive system
Discussed the role of testosterone
Described the process of spermatogenesis
Discussed the organs of the female reproductive system
Discussed the role of estrogen
Described the process of oogenesis

47. Summary (cont’d.) Described the phases of the menstrual cycle
Discussed pregnancy and embryonic development