Structure and Function of the Reproductive System Chapter 3

1. Structure and Function of the Reproductive System Chapter 3

2. OBJECTIVES 1. Explain two major functions of the reproductive system. 2. Label an anatomic drawing of the female and male reproductive systems, including external genitalia and internal anatomy. 3. Discuss major functions of each reproductive structure, gland, and organ. 4. Trace the path of sperm through the male reproductive system, from the site of formation to ejaculation from the body. 5. Describe the process of semen production. 6. Compare hormonal regulation of male reproductive function with that of the female. 7. Illustrate the inter-relationships of the ovarian and uterine cycles and the overall menstrual cycle. 8. Describe and compare the male and female sexual response cycles.

3. Reproductive Systems • External and internal parts • 2 Main purposes – produce offspring & allow for sexual intimacy and fulfillment • Secondary function • Provide a conduit for urinary elimination • Most structures paired (e.g., testes, ovaries, labia majora, labia minora) • Male and female systems complementary (ex.: testes & ovaries, scrotum & labia majora, glans penis & clitoris)

4. Male Reproductive System • Testes produce gametes (sperm) • Contains one half of genetic material needed to produce human baby • Urinary tract and reproductive system closely connected

5. Male Reproductive Anatomy

6. Male External Genitalia • Penis • Composed of a bulbous head, called the glans penisor glans, and a shaft • Serves a dual role as the male organ of reproduction and as the external organ of urinary elimination • Scrotum • An external sac that houses the testes in two internal compartments • Protects the testes from trauma and regulates the temperature within the testes

7. Male Internal Reproductive Organs • Testes • Two oval organs, one within each scrotal sac • Produce male sex hormones (androgens) or testosterone and form mature spermatozoa • Ductal system (vas deferens) • The muscular tube in which sperm begin their journey out of a man’s body • Involved in the formation of nutrient plasma -enhancement of sperm motility -nourishment of sperm -protection of sperm (i.e.: the acidic environment of vagina)

8. Male Internal Reproductive Organs (cont.) • Accessory glands and semen • Seminal vesicles • Paired glands that empty an alkaline, fructose-rich fluid into the ejaculatory ducts during ejaculation • Prostate-muscular gland that surrounds the first part of the urethra as it exits the urinary bladder (approx. size of chestnut) • Cowper’s-(bulbourethral) glands-secretes an alkaline fluid that coats the last part of the urethra during ejaculation • Semen-(alkaline fluids and sperm combination)

9. Sperm’s Journey through Male Reproductive Tract • Formation-sperm produced in seminferous tubules of testes • Maturation-the sperm then move through a maze of tiny ducts into the epididymuswhere they mature • Path into the abdominal cavity-the sperm eventually drain into the vas deferens that travels up through the scrotum inside the spermatic cord • The vas deferens continues upward to the bladder where it is joined by the excretory duct of the seminal vesicle, forming the ejaculatory duct (connecting duct) • Ejaculatory duct joins with urethra within the prostate • Urethra extends to the tip of penis-path out of the man‘s body

10. Reproductive Hormone Production and Function

11. Female Reproductive System • Composition • The external genitalia (vulva) and internal reproductive organs • Functions • Allow for sexual intimacy and fulfillment • Produce children through the processes of conception, pregnancy, and childbirth

12. Female External Reproductive Anatomy

13. External Genitalia of the Female Reproductive System • Mons pubis • Located atop symphysis pubis • Labia majora • Paired fatty tissue folds • Extends from mons pubis to true perineum • Labia minora • Paired erectile tissue folds

14. External Genitalia of the Female Reproductive System (Cont.) • Clitoris • Hooded body composed of erectile tissue • Prepuce is the hooded structure over the clitoris • Vestibule • Area between the labia minora • Location of urethral meatus • Perineum • Band of fibrous, muscular tissue

15. Question Indicate whether the statement below is true or false. The Cowper’s glands, the seminal vesicles, and the prostate gland are considered the accessory glands of the internal portion of the male reproductive system.

16. Answer True Rationale: The seminal vesicles, the prostate gland, and the bulbourethral (Cowper’s) glands are considered accessory glands of the male internal reproductive system.

17. Female Internal Reproductive Anatomy

18. Anterior View-Female Reproductive Anatomy

19. Internal Reproductive Organs • Vagina (birth canal) • A muscular tube that leads from the vulva to the uterus • Fornices • Uterus (womb) • A hollow, pear-shaped, muscular structure • Functions • Prepare for pregnancy each month • Protect and nourish the growing child

20. Internal Reproductive Organs (cont.) • Uterus (womb) (cont.) • Four sections • Cervix • Connects the vagina and uterus • Outer os

21. Internal Reproductive Organs (cont.) • Uterus (womb) (cont.) • Four sections (cont.) • Uterine isthmus • Connects the cervix to the main body of the uterus • Thinnest portion of the uterus, and does not participate in the muscular contractions of labor • Most likely to rupture during childbirth

22. Internal Reproductive Organs (cont.) • Uterus (womb) (cont.) • Four sections (cont.) • Corpus • Main body of the uterus • Fundus • Topmost section of the uterus

23. Internal Reproductive Organs (cont.) • Uterus (womb) (cont.) • Walls of the corpus and fundus have three layers • Perimetrium • Myometrium • Endometrium

24. Internal Reproductive Organs (cont.) • Paired fallopian tubes • Tiny, muscular corridors 8-14 cm long • 3 sections • Isthmus • Ampulla • Infundibulum

25. Internal Reproductive Organs (cont.) • Ovaries • Two sex glands homologous to the male testes; located on either side of the uterus • Functions • Produce the female hormones estrogen (FSH) and progesterone (LH) • Store ova and help them mature • Regulate the menstrual cycle in response to anterior pituitary hormones(Follicle stimulating hormone, Leutinizing hormone)

26. Question Which portion of the uterus is most likely to rupture during childbirth? a. Cervix b. Isthmus c. Corpus d. Fundus

27. Answer b. Isthmus Rationale: The uterine isthmus is the thinnest portion of the uterus and does not participate in the muscular contractions of labor. Because the tissue is so thin, the isthmus is the area that is most likely to rupture during childbirth.

28. Regulation of Reproductive Function • Puberty • The time of life in which an individual becomes capable of sexual reproduction • Occurs between 10 and 14 years of age • Development of secondary sex characteristics • Menarche

29. Regulation of Reproductive Function (cont.) • Menstrual cycle • Recurring changes that take place in a woman’s reproductive tract associated with menstruation and the events that surround menstruation • Menstruation • The casting away of blood, tissue, and debris from the uterus as the inner lining sheds • Flow lasts 4 to 6 days • Can contribute to low iron stores and anemia

30. Regulation of Reproductive Function (cont.) • Menstrual cycle (cont.) • Encompasses the events that transpire in a woman’s reproductive organs between the beginnings of two menstrual periods • Ovarian cycle and the uterine cycle

31. Regulation of Reproductive Function (cont.) • Menstrual Cycle (cont.) • Ovarian cycle and the uterine cycle • Ovarian cycle • Follicular phase • Controlled by FSH • Encompasses days 1-14 of a 28-day cycle • Ovulation

32. Regulation of Reproductive Function (cont.) • Menstrual Cycle (cont.) • Ovarian cycle and the uterine cycle (cont.) • Luteal phase • Controlled by luteinizing hormone • Includes days 15-28

33. Regulation of Reproductive Function (cont.) • Menstrual cycle (cont.) • Uterine cycle • Refers to the changes that occur in the inner lining of the uterus • Four phases • Menstrual phase • Day 1 of the menstrual cycle: onset ofmenstruation

34. Regulation of Reproductive Function (cont.) • Menstrual cycle (cont.) • Uterine cycle (cont.) • Menstrual phase (cont.) • Uterine lining is shed • Follicle begins to develop • Ends when the menstrual period stops on approximately day 5 of the cycle

35. Regulation of Reproductive Function (cont.) • Menstrual cycle (cont.) • Uterine cycle (cont.) • Proliferative phase • Uterine lining becomes thicker • Ends with ovulation on day 14

36. Regulation of Reproductive Function (cont.) • Menstrual cycle (cont.) • Uterine cycle (cont.) • Secretory phase • Corpus luteum begins to produce progesterone • Prepares for pregnancy

37. Regulation of Reproductive Function (cont.) • Menstrual cycle (cont.) • Uterine cycle (cont.) • Ischemic phase • Days 27 and 28, estrogen and progesterone levels fall • Uterine lining becomes ischemic and begins to slough

38. Regulation of Reproductive Function (cont.) • Menstrual cycle (cont.) • Cervical mucus changes • Menstrual phase – cervix does not produce mucus • Proliferative phase – a tacky, crumbly type of mucus that is yellow or white • Ovulation - distensible, stretchable quality called spinnbarkheit • After ovulation – mucus becomes scanty, thick, and opaque

39. Regulation of Reproductive Function (cont.) Menopause • Reproductive capability ends • Ovaries cease to function • Hormone levels fall • Climacteric • Usually between 47 and 55 years of age

40. Sexual Response Cycle • Two physiological responses • Vasocongestion • Occurs in the pelvic organs during sexual excitement • Leads to erection of the penis and clitoris, vaginal lubrication, and engorgement of the labia and testicles • Myotonia • Present throughout the body • Produces muscular contractions during orgasm

41. Sexual Response Cycle (cont.) • Four phases • Excitement phase • Plateau phase • Orgasm phase • Resolution phase

42. Excitement Phase of the Sexual Response • Female • Clitoris becomes engorged and enlarged • Labia majora separate; labia minora increase in size • Uterus increases in size and begins to elevate • Male • Penis becomes erect • Scrotal sac thickens • Testicular elevation occurs

43. Plateau Phase of the Sexual Response • Female • The outer third of the vagina becomes engorged, the clitoris retracts behind its hood, and the labia minora deepen in color • The uterus is fully elevated in the pelvic cavity • Male • The head of the penis in the male becomes further engorged, and the testes remain engorged and elevated

44. Orgasm Phase of the Sexual Response • Female • The clitoris remains retracted behind the hood, and the outer third of the vagina, rectal sphincter, and uterus undergo rhythmic contractions • Male • Experiences contractions of the urethra, base of the penis, and rectal muscles, as well as emission and expulsion of semen

45. Resolution Phase of the Sexual Response • Female • The clitoris descends, and the labia and internal organs return to their prearoused positions and colors • Male • Erection is lost • Testes descend • Scrotum thins

46. Question What event marks the beginning of the plateau phase in the sexual response cycle? a. Engorgement of the clitoris b. Series of muscular contractions c. No specific event d. Testes descend

47. Answer c. No specific event Rationale: No set event marks the beginning of the plateau phase.

48. Case Study • The nurse in the local middle school is planning to provide an education on the reproductive system to the fifth-grade girls and boys. The educational offerings will be on different days, and the girls and boys will be in separate groups. The parents are encouraged to attend with their children. (Learning Objectives 1 & 3). • *Answer the following questions and provide as much specific information as possible, keeping in mind how the nurse would respond to the students and the parents. • 1) The nurse is planning to start the discussion with an overview of the menstrual cycle. Discuss the typical menstrual cycle. • 2) The students want to know what makes the girls and boys different. Discuss the anatomical differences and major functions of each reproductive structure, gland, and organ for males and females. Q#1