Reproduction and Development

1. Reproduction and Development Chapter 16 pg 510

2. Unit Overview • Male reproductive system • Principle hormones in male • Female reproductive system • Principle hormones in females • Chromosomal and hormonal factors on gonads • Hormonal influence on primary and secondary sex characteristics • STI’s and their influence on fertility and reproduction • Process of fertilization and implantation • Development from fertilization to parturition • Major tissues or organs that develop from ectoderm, mesoderm, endoderm • Influence of environmental factors on embryonic development • Reproductive technologies

3. What Do You Know???

4. Primary Sex Characteristics • Physical characteristics directly involved in reproduction • Testis/ovaries • Uterus • Sperm/eggs

5. Male Reproductive System pg 512-513

6. Structures of the Male Reproductive System • Testes – male gonads, produce sperm, hang outside the body • Seminiferous tubules – site of spermatogenesis • Interstitial cells – between seminifrous tubules, produce testosterone • Sertoli cells- provide support to developing sperm cells

7. Structures of the Male Reproductive System • Epididymides – along posterior boarder of testis, coiled tubes, stores sperm cells • Vasa (ductus) deferentia– tube that conducts sperm towards urethra • Cowper’s glands – contributes mucus rich fluid to seminal fluid to protect sperm from acids in the urethra • Seminal vesicles- contributes fructose and prostaglandins to the seminal fluid

8. Structures of the Male Reproductive System • Prostate gland – secretes buffers into the seminal fluid that protect the sperm cells from the acidic environment of the vagina • Ejaculatory duct –tubule formed where the vasadeferentia and seminal vesicles join the urethra • Urethra – carries seminal fluid during ejaculation • Penis

9. Spermatogenesis – pg 514 • Formation of sperm cells SpermatogoniaSpermacytesSpermatids • Takes 9-10 weeks • Developed in Sertoli Cells • Mature in epididymis

10. Testes and Sperm

11. Seminal Fluid – pg 516 • Contributed to by 3 glands along the vasadeferentia and ejaculatory duct • Seminal Vesicles – fructose (energy) and prostoglandins (chemical signal in female reproductive system) • Prostate Gland – alkaline buffer against acidic vaginal fluids • Cowper’s Gland – mucus rich fluids to protect against acids found in the urethra • Only live for 24-72 hours at body temperature

12. Principle Male Reproductive Hormones – pg 517 • Testosterone • produced in interstitial cells • stimulates maturation of testes, penis, and speramtogenesis • Promotes development of secondary sex-characteristics • Associated with secretion of body oils (acne and body odor) • Associated with sex drive and aggressive behavior

13. Follicle-stimulating Hormone (FSH) • Stimulates production of sperm cells in the seminiforous tubules • Luteinizing Hormone (LH) • Promotes the production of testosterone by the interstitial cells • Gonadotropin-releasing Hormone (GnRH) • Stimulates the release of FSH and LH

14. Secondary Sex Characteristics in Malespg 517 • External features that are indicative of gender • Hair • Chest and abdomen • Facial • Armpits and pubis • Enlarged Larynx (deeper voice) • Larger, stronger muscles • Fat deposits around the abdomen and waist • Coarser skin texture • Typically larger hands and feet than women • Angle from thigh to ankle forms a strait line

15. Cancers of the Male Reproductive System • Testicular • Most common cancer in males between 15-34 • Lump or enlarged testicle • Pain in scrotum • Dull ache in abdomen or groin • Prostate • Ususally detected through screening • Symptoms include • Urinary problems • Blood in urine or semen • Pain in pelvic area

16. Vasectomy Video

17. Review • Homework package • Quiz tomorrow

18. The Female Reproductive System pg 520

19. External Structures of the Female Reproductive System

20. Structures of the Female Reproductive System • Ovaries – site of ovum maturation, contain oocytes (immature ova, all present at birth) • Fallopian tubes – connect the ovaries to the uterus (oviduct) • Uterus (Womb) – where fetus develops, muscular outer lining, glandular inner layer • Endometrium – inner lining of the uterus, grows and sheds during the reproductive cycle

21. Structures of the Female Reproductive System • Cervix – muscular band that separates the vagina from the uterus • Vagina – muscular canal extending from the cervix to outer environment (birth canal) • Labia Majora– outer lips of the vulva • Labia Minora – inner lips of the vulva • Clitoris • Urethra – not connected to reproductive system in females

22. Oogenesis and Ovulation – pg 522 • Oogenesis– formation of an ovum • Occurs in follicles • Begins when nutrient follicle cells surrounding the secondary oocyte begin to divide • Fluid filled cavity is formed

23. Follicle pushes outward ballooning ovary wall • Constriction of blood vessels weakens ovary wall • Outer wall bursts and secondary oocyte is released (ovulation) • Surrounding follicle cells turn in to corpus luteumwhich secretes hormones necessary for pregnany

25. Menstrual Cycle – pg 524 • Includes oogenesis, ovulation, thickening and shedding of the endometrium • 4 phases • Lasts and average of 28 days

26. Flow Phase • Only phase that can be determined externally • Approximately 5 days • Shedding of the endometruim

27. Follicular Phase • Development of follicles within ovary • Estrogen secreted as follicles develop • Normally days 6-13

28. Ovulatory Phase • Secondary oocytebursts from ovary • Follicular cells differentiate into corpus luteum • Day 14

29. Luteal Phase • Begins with development of corpus luteum • Estrogen and Progesterone are secreted • Progesterone prepares uterus for an embryo

30. Progesterone prevents further ovulation, prevents uterine contractions, firms the cervix • Days 15-28

31. pg 528 • If no fertilization, concentrations of progesterone and estrogen decrease causing uterine contractions and endometrial shedding

33. Female Reproduction Throughout Her Lifespan • Ovaries undergo continual decline after puberty • At puberty, each ovary contains approximately 400 000 folicles • During each cycle, many follicles develop but usually only one is released (others are re-absorbed) • Between 12-50, about 400 eggs will mature • Suggested that older follicles have a greater chance of genetic defect • Menopause • when ovulation ceases • Drop in production of female hormones

34. Principle Female Reproduction Hormones – pg 526 • Estrogen • Inhibits growth of facial hair • Initiates secondary sex characteristics • Causes thickening of the endometrium • Progesterone • Inhibits ovulation • Inhibits uterine contractions • Firms the cervix • Stimulates the endometrium

35. Follicle Stimulating Hormone • Regulate control of hormones produced by ovaries • Carried to ovaries during follicular phase • Follicle development is stimulated • Luteunizing Hormone • Regulate control of hormones produced by ovaries • Stimulated by by rise in estrogen • LH secretion rises and ovulation occurs • Formation and maintenance of corpus luteum

36. Secondary Sex Characteristics in Females pg 520 • Enlarged breasts • Less facial hair than men • Hair growth in armpits and pubis • Wider at hips and shoulders • Fat deposits around buttocks and hips • More body fat than men • Hands and feet typically smaller and narrower than males • Angle from thigh to ankle is slightly bent

37. Tubal Ligation Video

38. Cervical Cancer • Detection • PAP test and Pelvic examination • Possible symptoms • abnormal bleeding from the vagina • bleeding or spotting between regular menstrual periods • bleeding after sex • menstrual periods that last longer and are heavier than before • bleeding after menopause • more discharge from the vagina than normal • pain in the pelvis or lower back • pain during sexual intercourse • Risk Factors • HPV infection (main risk factor) • not having regular Pap tests (a test used to detect both dysplasia and cervical cancer) • becoming sexually active at a young age • having many sexual partners or a sexual partner who has had many partners • smoking • having a weakened immune system (for example, from taking drugs after an organ transplant or having a disease such as AIDS) • using birth control pills for a long time • giving birth to many children

39. Ovarian Cancer • Types • Epithelial cell cancer starts in the cells that cover the outer surface of the ovary. • Germ cell tumoursstart in the egg cells within the ovary and generally occur in younger women. Germ cell cancer can even develop in children. • Stromaltumoursstart in the connective tissue cells that hold the ovary together. • Risk Factors • age – particularly after 50 • personal history of cancer • a family history of ovarian cancer or breast cancer or if a woman has hereditary mutations on certain genes • never having been pregnant • taking hormone replacement therapy (especially estrogen-only therapy) for a long period of time • Symptoms • abdominal discomfort, pressure or pain • change in bowel habits • feeling full after a light mea • upset stomach • feeling that the bowel has not completely emptied • Nausea • Fatigue • pain in lower back or leg

40. Breast Cancer • Risk Factors • having had breast cancer before • family history of breast cancer (especially in a mother, sister or daughter diagnosed before menopause or if mutations on BRCA1 or BRCA2 genes are present) • family history of ovarian cancer • an above-average exposure to the hormone estrogen, which your body naturally produces, perhaps because you: • have never given birth or gave birth for the first time after age 30 • began menstruating at a young age • reached menopause later than average • have taken hormone replacement therapy (estrogen plus progestin) for more than five years • dense breast tissue (as shown on a mammogram) • a history of breast biopsies showing certain breast changes, such as an increased number of abnormal cells that are not cancerous (atypical hyperplasia) • radiation treatment to the chest area (for example, to treat Hodgkin lymphoma), especially before age 30 Some factors slightly increase your risk of breast cancer. You may be at slightly higher risk if you: • are obese (especially after menopause) • drink alcohol • take birth control pills (the Pill)

41. Breast Cancer • Symptoms • lump or swelling in the armpit • changes in breast size or shape • dimpling or puckering of the skin – thickening and dimpling skin is sometimes called orange peel • redness, swelling and increased warmth in the affected breast • inverted nipple – nipple turns inwards • crusting or scaling on the nipple • Early Detection • Self-exam • Mammograms

42. Review • Homework Package • Quiz Wednesday

43. Sex Determination – pg 535 • Females have 2 X chromasomes • Males have 1 X and 1 Y • Male and female fetus’ are the same until week 6 or 7 • SRY gene makes the developing gonad a testis • Also determined by hormones circulating in the blood stream • Too much estrogen at the wrong time can form a male organism that is outwardly female • Over abundance of androgens can produce male sex organs in a genetically female body

44. “The Disappearing Male” • Things to consider • Everyday exposures • Dangers of common products • What it would mean to society if males became less common or predominantly infertile • Could this become a political issue