1. Reproductive1 Reproductive System rev 5-11 The term genitalia refers to male and female reproductive organs. Male Reproductive System Anatomy The scrotal sac contains 2 testes. –The process of sperm formation is called spermatogenesis.

2. Reproductive2 The testes are located outside of the body because sperm need lower temperatures to survive. Sperm production takes place in the seminiferous tubules of the testes –In between the seminiferous tubules are interstitial cells which produce testosterone, the male hormone. Many seminiferous tubules join to become the epididymus. Sperm are stored here and maturation also occurs.

3. Reproductive3 Sperm enter the vas deferens or ductus deferens which passes through an opening in the wall of the body called the inguinal canal. –The ability of newly formed sperm to swim develops in the epididymis and the vas deferens. –Sperm continue their maturation here. –A vasectomy ties off the vas deferens so sperm are no longer available for fertilization.

4. Reproductive4 The vas deferens connects to the ejaculatory duct after it merges with the seminal vesicle duct. When the male ejaculates semen, rhythmic contractions of smooth muscle propel the sperm through the ejaculatory duct and then through the urethra. The penis is the male organ of sexual intercourse. It contains erectile tissue that fills with blood and causes the erection during sexual stimulation.

5. Reproductive5 Glands which help sperm survive: Seminal vesicles produce seminal fluid which is a watery mixture containing fructose, which provides energy for the sperm, and prostaglandins which are thought to induce muscle contractions. Prostate gland:produces an alkaline fluid which raises the pH of the vagina to a more optimal pH. Cowper’s or bulbourethral glands secrete mucus into the urethra during sexual arousal. This provides lubrication for intercourse and washes away traces of acidic urine

6. Reproductive6 Sperm Production Meiosis: –Purpose: produces sperm and eggs with half the number of chromosomes (23) of somatic cells. (Cells with ½ the chromosomes are called haploid cells.) –Sperm formation and maturation takes about 9-10 weeks. Sertoli cells surround and nourish the growing sperm cells. –Egg maturation and release takes about 14 days and occurs once per month

7. Reproductive7 Cell division terminology: Gamete: sperm or egg produced by meiosis Diploid: describes the “normal” number of chromosomes in any cell Haploid: cell which contain 23 chromosomes

8. Reproductive8 Sperm consist of 3 major parts: a head, midpiece, and a tail. The head contains the nucleus and 1/2 of the chromosome number of the parent. –Acrosome covers the head. –The midpiece contains mitochondria and ATP. The tail propels the sperm.

9. Reproductive9 Regulation of Male Reproductive Activity Hormones: Testosterone: –Source: Leydig cells in seminiferous tubules –Function: controls growth and function of male reproductive tissues, stimulates aggression and sexual behavior, and secondary sexual characteristics GnRH: Gonadotropin-releasing hormone from the hypothalamus; stimulates the anterior pituitary gland to release LH and FSH LH: stimulates production of testosterone FSH (Follicle Stimulating Hormone) : may enhance sperm formation

10. Reproductive10 The Female Reproductive System Anatomy: The external female genitalia or vulva: the Mons Pubis, a fatty, rounded tissue area, covers the pubic symphysis. The Labia Majora are 2 elongated, pigmented, hair covered, fat padded skin folds which surround and enclose the Labia Minora.

11. Reproductive11 The Labia Minora are 2 smaller, highly vascular, hair free folds. The Clitoris is a small organ partly enclosed by the labia minora. The Urethral opening lies between the clitoris and the vaginal opening.

12. Reproductive12 Internal female reproductive organs Ovaries are the primary reproductive organs. They lie near the ends of the fallopian tubes (also called oviducts). The ovaries produce eggs called oocytes. Eggs have 1/2 the number of chromosomes as the parent.

13. Reproductive13 They also produce the hormones estrogen and progesterone The distal ends of the fallopian tubes are funnel shaped and have fingerlike projections called fimbriae. The egg is propelled toward the uterus by the cilia on the walls of the fallopian tubes. If fertilization by a sperm occurs, it usually takes place in the distal third of the fallopian tube.

14. Reproductive14 The uterus is a hollow, pear shaped, muscular organ which is located between the bladder and the rectum. It will “incubate” the fertilized egg. Its narrow, lower end is called the cervix. The middle part of the uterus is called the body and the upper part is called the fundus.

15. Reproductive15 Uterine layers –Endometrium: inner layer A fertilized egg will implant into this layer. After implantation, the endometrium helps form the placenta. This is the layer that sloughs off during menstrual flow. –Myometrium: middle, muscular layer –Perimetrium: outer layer –Cervix: the narrow opening in the lower part of the uterus

16. Reproductive16 The cervix joins the vagina. –It serves as a birth canal and the female organ for sexual intercourse. –It permits the passage of menstrual blood to the outside of the body. –Vestibular glands secrete lubricating mucus.

17. Reproductive17 The Breasts are considered to be part of the reproductive organs are really modified sweat glands which produce milk to nourish newborn infants. milk production (lactation) is stimulated by estrogen and progesterone only when birth has actually occurred. the nipple is at the center of each breast. It contains smooth muscles that can contract and cause the nipple to become erect.

18. Reproductive18 Surrounding the nipple is the pigmented areola. Internally, the breasts contain mammary glands that produce milk. –The glands consist of many milk producing lobules. Contractile cells around each lobule allow the milk to be released and ducts deliver the milk to the nipple.

19. Reproductive19 Menstrual Cycle Each month the ovaries and uterus go through a pattern of changes called the menstrual cycle. –Typically lasts 28 days; is controlled by hormones –Menstrual cycles begin at puberty and end at menopause A complete menstrual cycle consists of 2 linked cycles: an ovarian and a uterine cycle Ovarian cycle: oocytes mature and are released –Immature follicle develops; GnRH, FSH and LH increase

20. Reproductive20 –Estrogen and progesterone secreted –Follicle matures; now called Graafian follicle –Increasing estrogen causes surge of LH so that ovulation occurs—the egg is released –A corpus luteum forms from the ruptured follicle site and secretes large amounts of estrogen and progesterone to prepare the endometrium for the possible pregnancy –If no pregnancy occurs, estrogen and progesterone levels decline and another menstrual cycle begins.

21. Reproductive21 –If the egg is fertilized, it moves down the fallopian tube and implants in the uterine endometrium –The developing embryo secretes its own hormones to enable the corpus luteum to continue to secrete estrogen and progesterone until the placenta develops. –The placenta will take over the job of secreting progesterone and estrogen as well as become a nutrient/waste filter between the maternal and fetal circulation.

22. Reproductive22 Uterine cycle: prepares uterus for pregnancy Menstrual phase: With no pregnancy, days 1–5, estrogen and progesterone decrease, endometrial lining degenerates, menstruation occurs –Proliferative phase: days 6–14, estrogen and progesterone increase, endometrial lining begins to proliferate –Ovulation: day 14

23. Reproductive23 –Secretory phase: corpus luteum produces progesterone and estrogen, endometrium continues to proliferate, uterine glands mature and produce glycogen as a potential energy source for an embryo

24. Reproductive24 Maintenance of Menstrual Cycle Cycles of hormones of pituitary and reproductive structures: –Positive feedback: In proliferative phase, increasing estrogen causes surge in LH –Negative feedback: In secretory phase, steady levels of estrogen and progesterone inhibit LH and FSH release

25. Reproductive25 Infertility: Inability to Conceive Many causes of infertility: –Number and quality of sperm, pelvic inflammatory disease (PID), endometriosis Enhancing fertility: –Options: artificial insemination, in vitro fertilization, GIFT and ZIFT, fertility-enhancing drugs, surrogate mothers

26. Reproductive26 Sexually Transmitted Diseases (STDs): Worldwide Problem Bacterial: gonorrhea, syphilis, chlamydia Viral: HIV, hepatitis B, genital herpes, genital warts Other: yeasts (Candida), protozoan (Trichomonas), arthropod (pubic lice) Prevention: –Strategies: choose partner wisely, communicate, use suitable barriers, get tested and treated