1. The Reproductive System
Chapter 16

2. The Reproductive System
Gonads- Primary Sex Organs
Males - Testes
Females - Ovaries
Produce sex cells “gametes”
Males – sperm
Females – eggs
Secrete sex hormones

3. Male Reproductive System
Testes
Duct System
Epididymis
Ductus Deferens
Urethra
Accessory Glands and Semen
Seminal vesicles
Prostate gland
Bulbourethral Glands
Semen
External Genitalia
Scrotum
Penis

4. Male Reproductive System

5. Testes Coverings of Testes Tunica albuginea Septa
White coat surrounding each testes
Septa
Divides testes into a large number of lobules

6. Testes
Each lobule contains one of four tightly coiled seminiferous tubules
“sperm-forming factories”
Empty sperm into rete testis
Sperm travels through rete testis to epididymis
Intersitial cells produce horomones
More specifically testosterone

7. Epididymis Comma shaped highly coiled tube
Provides storage site for immature sperm that enter testis
Sperm mature while in epididymis over 20 days
When sexually stimulated- walls contract to expel sperm to ductus deferens

8. Ductus Deferens (vas deferens)
Propels live sperm from epididymis to urethra by perisalisis
End of ductus deferens empties into ejaculatory duct
Spermatic cord- ductus deferense, blood vessels and nerves
Vasectomy – cutting of ductus deferense – leads to sterility but no loss in sex drive

9. Urethra Extends from base of urinary blader to tip of penis 3 regions
Prostatic urethra – surrounded by prostate gland
Membranous urethra – distance from prostatic urethra to penis
Spongy (penile) urethra – runs within length of penis
Carries both urine and sperm
Never pass at the same time

10. Seminal Vesicles At base of bladder
Produce about 60% of fluid volume of semen
Thick yellowish secretion rich in sugar, vitamin C, prostaglandins and other substances
Nourish and activate the sperm

11. Prostate Gland Encircles upper part of urethra
Secrets milky fluid that activates sperm
Enters urethra through several small ducts

12. Bulbourethral Glands
Produce thick, clear mucus that drains into penile urethra
First secretion to pass when man become sexually excited
Cleans out traces of acidic urine
Serves as lubricant for sexual intercourse

13. Semen
Milky white, somewhat sticky mixture of sperm and gland secretions
Provides transport, nutrients, and chemicals that protect sperm and aid in movement

14. External Genitalia Scrotum Penis
Sac of skin hanging outside abdominal cavity
Provides temperature about 30 C lower than body temp for healthy sperm
Penis
Delivers sperm to female reproductive tract
Regions of the penis
Shaft
Glans penis – enlarged tip
Prepuce or foreskin – cuff of skin
Can be removed in circumcision
Erection – spongy urethra that fills with blood during sexual excitement

15. Spermatogenesis Production of sperm
Starts during puberty and continues throughout life
Every day man makes millions of sperm
Sperm formation takes place in seminiferous tubules of testis

16. Spermatogenesis Spermatogonia
Rapid mitoic divison to build up stem cell line
Follicle-stimulating hormone modifies division
Division produces two types of cells
One stem cell
Primary spermatocyte

17. Spermatogenesis Primary spermatocytes undergo meiosis
Produce four sperm – spermatids

18. Spermatogenesis Spermiogenesis Entire process takes 64-72 days
Maturing of spermatids into sperm cells
3 regions of mature sperm
Head – contains DNA
Midpiece
Tail
Entire process takes days

19. Anatomy of a Mature Sperm
DNA is found in head
Only flagellated cell in human body

20. Threats to Sperm Formation
Penicillin
Tetracycline
Radiation
Lead
Certain pesticides
Marijuana
Tobacco
Excessive alcohol

21. Testosterone Production
Produced in testes in intersitial cells
Stimulates reproductive organ development
Underlies sex drive
Causes secondary male sex characteristics
Deepening of voice
Increased hair growth
Enlargement of skeletal muscles
Increased heaviness of skeleton

22. 21 slides
6 picture only slides
2 picture and word slides
13 word slides

23. Female Reproductive System
Ovaries
Duct System
Uterine tubes (fallopian tubes)
Uterus
Vagina
External Genitalia

24. Female Reproductive System

25. Ovaries Primary reproductive organ Ovarian follicles
Sac like structures
Oocyte
Follicle cells

26. Ovarian Follicle Stage
Primary follicle- contains immature oocyte
Graafian follicle- enlargement of follicle and maturation of oocyte
Ovulation- rupturing of follicle and ejection of developed egg
Occurs about every 28 days
Corpus luteum- transformed ruptured follicle

27. Support for Ovaries
Suspensory ligaments – secure ovaries to lateral walls of pelvis
Ovarian ligaments – anchor ovaries to uterus
Broad ligaments – enclose and hold ovaries in place by a fold of peritoneum

28. Support for the Ovaries

29. Uterine Fallopian Tubes
Initial part of duct system
Provide site where fertilization can occur
Does not connect to uterine tubes and ovaries
End of tube has fimbriae – fingerlike projections
Held in place by broad ligament
Move oocyte toward uterus (3-4 days) by peristalsis and rythmic beating of cilia

30. Uterus Located between urinary bladder and rectum
Receives, retains and nourishes a fertilized egg
Size and shape of pear in unpregnant woman
Suspended in pelvis by broad ligament and anchored by round and uterosacral ligaments

31. Support for the Uterus

32. Regions of the Uterus Body – main portion
Fundus – round region above entrance of uterine tubes
Cervix – narrow outlet protruding into vagina

33. Walls of the Uterus Endometrium
Inner layer
Where fertilized egg resides during development
Sloughs off about every28 days (menses) if not pregnant
Myometrium – middle layer of smooth muscle
Active role during delivery
Visceral peritoneum – outermoust serous layer

34. Vagina Thin-walled tube Extends from cervix to body exterior
Also known as birth canal
Receives penis and semen during sexual intercourse
Hymen is distal end of vagina and usually ruptures during first sexual intercourse

35. External Genitalia Mons pubis Labia – skin folds Vestibule Clitoris
Fatty, rounded area over pubic area
Usually covered with pubic hair
Labia – skin folds
Labia majora
Labia minora
Vestibule
Contains external opening of urethra
Greater vestibular glands- provide lubrication during intercourse
Clitoris
Composed of erectile tissue similar to penis

36. Oogenesis Total supply of eggs is determined by birth
Reproductive ability begins at puberty and ends around 50s (menopause)
Similar to formation of sperm in male testes

37. Oogenesis Oogonia – female stem cells found in a developing fetus
Mitosis occurs to produce primary oocytes
Primary oocytes surrounded by single layer of cells to form primary follicles
Oogonia does not exist after birth
Primary oocytes inactive until puberty

38. Oogenesis
Follicle-stimulating hormone released during puberty causing some primary follicles to mature
Meiosis starts inside maturing follicle
Produces seconday oocyte and first polar body is formed
Meiosis finishes only if sperm penetrates and fertilization occurs
Two more polar bodies are formed

40. Menstrual Cycle Cyclic changes of endometrium
Controlled by cyclic production of estrogen and progesterone by ovaries
Stages of the menstrual cycle
Menses
Day 1-5: functional layer of endometrium is sloughed off
Accompanied by 3 – 5 days of bleeding
Proliferative stage
Day 6 – 14: regeneration of endometrium layer
Secretory stage
Day 15 – 28: endometrium increases in size and becomes ready for implantation

41. Hormone Control of Ovarian and Uterine Cycles

42. Hormone Control of Ovarian and Uterine Cycles

43. Hormone Production of the Ovaries
Estrogens
Produced by follicle cells
Causes appearance of secondary characteristics
Enlargement of accessory organs
Development of breasts
Appearance of pubic and axillary hair
Increased deposits of fats in hips and breasts
Widening and lightening of pelvis
Onset of menses (menstrual cycle)
Progesterone
Produced by corpus luteum
Produced as long as LH is present
Helps maintain pregnancy

44. Mammary Glands

45. Male Reproductive System

46. Male Reproductive System

47. Male Reproductive System

48. Male Reproductive System

49. Male Reproductive System

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51. Male Reproductive System

52. Male Reproductive System

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57. Male Reproductive System