1. THE REPRODUCTIVE SYSTEM

2. Introduction Most organ systems of the body function continuously to maintain the well-being of the individual. However, the reproductive system appears to “slumber” until puberty. The male and female reproductive systems are quite different but their joint purpose is to produce offspring.

3. Primary Sex Organs - also known as gonads. Males = testes Females = ovaries Both produce sex cells or gametes and secrete sex hormones

4. Reproductive Roles: Males = make male gametes (sperm) and deliver them to the female reproductive tract Females = make female gametes (ova or eggs) These 2 join together to produce a fertilized egg.

5. ANATOMY OF THE MALE REPRODUCTIVE SYSTEM

6. Primary Reproductive Organs Testes (also known as male gonads) Accessory Structures = ducts or glands that deliver sperm

7. Testes: Seminiferous Tubules = sperm-forming factories (in testes) Interstitial Cells = surround the seminiferous tubules and produce male sex hormones (testosterone)

8. Duct System - accessory organs that transports sperm from testes Epididymis = “comma-shaped” structure on the superior part of the testes Function = stores immature sperm that enter from testes. As sperm make their way through the epididymis, they mature and gain ability to swim. (Journey = 20 days)

9. Duct System continued… Vas Deferens = runs up from epididymis and over the bladder Function = propels live sperm into the ejaculatory duct then to the urethra. Vasectomy - “birth control” for men - Surgeon cuts through the vas deferens and cauterizes it. This prevents sperm from moving though the reproductive system. The male is sterile at this point. Urethra = part of the urinary system BUT it also carries sperm to the body exterior

10. Accessory Glands - semen producing glands Seminal Vesicles = produces 60% of the fluid volume of semen - thick, yellow secretion Prostate Gland = produces a milky fluid that activates sperm Prostate Cancer - slow growing, hidden condition, BUT can be a swift and deadly killer in MEN Semen = milky white mixture of sperm and accessory gland secretions

11. External Genitalia: Scrotum = divided sac of skin that hangs outside the abdominal cavity and holds the testes Penis = delivers sperm into the female reproductive tract

12. Regions of the Penis: Shaft Glans penis – tip Foreskin - removed at birth (circumcision)

13. MALE REPRODUCTIVE FUNCTIONS Chief Role = produce sperm and the hormone testosterone Spermatogenesis = sperm production Begins during puberty and continues throughout life Every day, a man makes millions of sperm

14. 3 Regions of a mature sperm: Head - contains DNA (genetic material) Mid-piece Tail - one flagella (for movement and “swimming”) Environmental threats can alter the normal process of sperm formation: Radiation, pesticides, marijuana, tobacco, and alcohol can cause the production of 2- headed and multiple tailed sperm.

15. Testosterone Production Testosterone stimulates the male’s reproductive organs to develop to their adult size and causes secondary sex characteristics

16. Secondary Male Sex Characteristics: Deep voice Increase in hair growth Increase in the size of skeletal muscles and bones

17. ANATOMY OF THE FEMALE REPRODUCTIVE SYSTEM

18. Primary Reproductive Organs Ovaries - also known as female gonads Accessory Structures Ducts that transport, nurture, and serve the needs of the reproductive cells and the developing fetus

19. Ovaries: Two of them Shape = look like almonds Ovarian Follicle = contains an immature egg (oocyte). When egg becomes mature, follicle ruptures and egg is ejected from the ovary (ovulation). Ovulation occurs every 28 days

20. Duct System: Fallopian Tubes = receive the ovulated oocyte and provide a site where fertilization can occur. Oocyte begins to move towards the uterus. This takes 3 to 4 days. Uterus = located in the pelvis between the bladder and rectum. It receives, retains and nourishes the fertilized egg.

21. Uterus Regions of the Uterus: Body Fundus - where fallopian tubes attach Cervix - goes into the vagina Lining of uterus is where a fertilized egg will burrow and attach in a pregnant woman. If a woman is NOT pregnant, the lining sloughs off about every 28 days.

22. Vagina tube that extends from cervix to body exterior Also known as the “birth canal” Receives penis during sexual intercourse

23. External Genitalia = also known as the vulva Mons Pubis = fatty rounded area that is covered with pubic hair after puberty Labia Majora = 2 hair covered skin folds that come down from the mons pubis and corresponds to the male scrotum Clitoris = corresponds to the male penis

24. FEMALE REPRODUCTIVE FUNCTIONS AND CYCLES A female’s reproductive ability (ability to release eggs) begins during puberty and ends in her 50s or before = Menopause = reproductive capability ends Oogenesis = female sex cell production - “the beginning of an egg”

25. Menstrual Cycle Cyclic changes that the lining of the uterus goes through month after month as it responds to changes in the levels of ovarian hormones in the blood. Female cycles are about 28 days Ovulation occurs midway in the cycle - about day 14 First 5 days of cycle = lining of uterus begins to slough off and is accompanied by bleeding for 3 to 5 days (Average Blood Loss = 1/4 to ½ cup)

26. Hormone Production by the Ovaries: Ovaries produce estrogens, which cause the appearance of secondary sex characteristics.

27. Secondary Female Characteristics: Enlargement of accessory organs of the female reproductive system Develop breasts Appearance of axillary and pubic hair Increases deposits of fat beneath skin in the hips and breasts Widening and lightening of pelvis Onset of menstrual cycle

28. Ovaries also produce progesterone = helps maintain the pregnancy and prepare breasts for milk production.

29. Growth and Development Because the birth of a baby is such a familiar event, we tend to lose sight of the wonder of this accomplishment. In every instance it begins with a single cell, the fertilized egg, and ends with an extremely complex human being.

30. Accomplishing Fertilization: Before fertilization can occur, the sperm must reach the ovulated egg. The ovulated egg (oocyte) is viable for 12 to 24 hours after it is cast out of the ovary. Sperm retain their fertilizing power within the female reproductive tract for 12 to 72 hours after ejaculation.

31. Therefore, for fertilization to occur, sexual intercourse must occur no more than 72 hours before ovulation and no later than 24 hours after ovulation. It takes 1 to 2 hours for sperm to complete their journey up the female duct system to the end of the fallopian tubes, and if an oocyte is present, fertilization is a distinct possibility.

32. Of the millions of sperm ejaculated by a male, only ONE can penetrate an oocyte. FERTILIZATION occurs at the moment the genetic material of a sperm combines with that of an ovum to form a fertilized egg = ZYGOTE.

33. Events of Embryonic and Fetal Development The zygote travels down the fallopian tube and begins rapid development. It attaches itself in the lining of the uterus and becomes known as the embryo. EMBRYO = developmental stage until the 9th week

34. Once the embryo attaches, the placenta forms and hCG is released by the embryo hCG prevents the menstrual cycle It is hCG that many home pregnancy tests detect for in a woman’s urine. PLACENTA = delivers nutrients and oxygen to and remove wastes from they embryonic blood. AMNION - fluid-filled sac that surrounds the fetus

35. By the 8th week, the embryo looks distinctly human. Beginning in the 9th week of development, the embryo is referred to as a FETUS. By the 12th week, sex is readily detected from the genital area of the fetus By approximately 270 days after fertilization, the fetus is said to be “FULL-TERM” and is ready to be born.

36. Effects of Pregnancy on the Mother: PREGNANCY = the period from conception to the birth of her baby. Anatomical changes in the mother: Enlargement of the uterus Increasing bulkiness of the abdomen Weight gain - a woman needs only about 300 additional calories daily to sustain proper fetal growth

37. Physiological changes in the mother: Gastrointestinal System Nausea = morning sickness during the first few months Heartburn = stomach is crowded by the growing uterus Constipation = movement of the digestive tract declines Urinary System Production of more urine Kidneys have to dispose of fetal metabolic wastes

38. Respiratory System Nasal stuffiness and Occasional nosebleeds Respiratory rate increases Cardiovascular System Total body water and blood volume increases to accommodate the additional needs of the fetus Blood pressure and pulse rise

39. Childbirth Also called PARTURITION Childbirth = “bringing forth young” - the culmination of pregnancy Usually occurs 280 days from the last menstrual period LABOR = the series of events that expel the infant from the uterus

40. Initiation of Labor: During the last few weeks of pregnancy, estrogens reach their highest levels in the mother’s blood Irregular uterine contractions can occur = BRAXTON HICKS CONTRACTIONS which is basically FALSE LABOR The mother undergoes an increase of emotional and physical stress and this triggers the hypothalamus to release its hormones. Once the hypothalamus is involved, true labor begins.

41. Stages of Labor: Dilation Stage = the time from the appearance of true contractions until the cervix is fully dilated (10 cm). The amnion ruptures = “breaking the water”. This is the LONGEST part of labor and usually lasts for 6 to 12 hours. Expulsion Stage = the period from full dilation to delivery of the infant. The infant passes through the cervix and vagina to the outside of the body. The mother will feel the urge to push or bear down with the abdominal muscles. This stage usually lasts about 50 minutes in a first birth. The umbilical cord is clamped and cut.

42. The head first presentation of the baby allows the baby to breathe even before it has completely ejected from the birth canal. Once the head has been delivered, the rest of the baby’s body is delivered much more easily. Breech presentation = “buttocks-first” - delivery is much more difficult C-Section = delivery of the infant through a surgical incision made through the abdominal wall.

43. Placental Stage = delivery of the placenta. It is usually accomplished within 15 minutes after birth of the infant. The placenta and its attached fetal membranes are called the AFTERBIRTH.

44. Developmental Aspects of the Reproductive System PUBERTY = the period of life, generally between the ages of 10 and 15 years, when the reproductive organs grow to their adult size and become functional under the influence of hormones