1 / 42

Reproduction

Reproduction. Ch. 28. Male Reproductive System. Objectives Describe location, structure, and function of the organs of the male reproductive system. Discuss the process of spermatogenesis in the testes. Organs of the Male. Testes – produce sperm and secrete hormones

sydney
Download Presentation

Reproduction

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Reproduction Ch. 28

  2. Male Reproductive System • Objectives • Describe location, structure, and function of the organs of the male reproductive system. • Discuss the process of spermatogenesis in the testes.

  3. Organs of the Male • Testes – produce sperm and secrete hormones • System of ducts (epididymis, ductus deferens, ejaculatory ducts, and urethra) – transports and stores sperm, assists in maturation • Accessory sex glands (seminal vesicles, prostate, and bulbourethral glands) – adds fluid to semen • Supporting structures – scrotum and penis – delivery and support

  4. Organs

  5. WORD BANK Vas deferens Scrotum Urethra Prostate Epididymus Bladder Teste Seminal Vesicle

  6. Organs • Scrotum (bag) – supporting structure for testes • Loose skin • Internally scrotum is divided into two sacs – one for each testis • Location of testes is vital to sperm survival • 2-3 degrees below normal body temperature • In cold – muscles pull the scrotum closer to the body to keep sperm warm • In warm – opposite occurs

  7. Organs • Testes or testicles • Descend during 7th month of pregnancy • Where sperm are made during spermatogenesis • Epididymis • Comma-shaped organ along the border of each testis • Site of sperm maturation – sperm acquire motility and ability to fertilize (14 days) • Stores sperm for up to several months

  8. Organs • Ductus deferens or vas deferens • Along border of epididymis and up around bladder • Pushes sperm during arousal toward the urethra • Also stores sperm for several months • Ejaculatory ducts • Eject sperm and seminal vesicle secretions before release of semen • Urethra • Passageway for urine and semen

  9. Organs • Seminal vesicles • Pouch like structures at base of bladder • Secrete alkaline fluid with fructose, clotting proteins, prostaglandins • Alkaline fluid neutralizes female acidity in vagina • Fructose is for ATP production in sperm for their swim • Clotting proteins help semen coagulate after ejaculation • Prostate • Doughnut shaped, golf ball sized organ • Secrete antibiotic for bacteria in urethra or vagina

  10. Organs • Bulbourethral glands or Cowper’s glands • Secrete alkaline fluid into urethra that protects sperm from urine • Secretes mucus for lubrication of external penis and urethra

  11. Semen • Mixture of sperm and seminal fluid • Seminal fluid from seminal vesicles, prostate, bulbourethral glands • Contains 2.4-5 mL of fluid with 50-150 million sperm/mL • 20 million/mL or lower is considered infertile • Slightly basic (7.2-7.7); milky appearance, sticky consistency • Seminal fluid provides sperm with nutrients, transportation, protection

  12. Penis • Contains urethra and passageway for ejaculation of semen and urine • Glans penis – head of penis • Erection – result of increased blood supply to penile tissue

  13. Penis

  14. Penis • Circumcision – removal of foreskin • Cleaner and decreases risk of infection or disease • Vasectomy • Sterilization of males • Portion of ductus deferens is removed • Ducts are cut and tied with stitches • Sperm production continues, but sperm cannot reach exterior of penis

  15. Spermatogenesis • Takes 65-75 days • Begins with spermatogonia (stem cells) • Undergo meiosis – 4 spermatids • Spermiogenesis • When spermatids become spermatozoa

  16. Review • Describe the function/structure of the following: • Testes • Epididymis • Ductus deferens • Ejaculatory ducts • Urethra • Seminal vesicles • Prostate • Bulbourethral glands • Scrotum • Penis • What is spermatogenesis?

  17. Female Reproductive System • Objectives • Describe the location, structure, and functions of the organs of the female reproductive system. • Discuss the process oogenesis in the ovaries.

  18. Organs of the Female • Ovaries – produce eggs and hormones • Uterine (fallopian) tubes or oviducts – transport egg to uterus, site of fertilization • Uterus – site of implantation of fertilized egg, development of fetus, labor • Vagina – receives penis, passageway for childbirth • External organs (vulva) • Mammary glands – synthesize, secrete, and eject milk for newborn

  19. Organs

  20. WORD BANK Cervix Fallopian Tubes Vagina Ovary Uterus

  21. Organs • Ovaries • Paired glands, almond sized • Produce • Gametes (egg cells) • Hormones (progesterone and estrogen, inhibin, relaxin) • Uterine tubes (fallopian) or oviduct • Extend away from uterus • Provide route for sperm to reach ovum • Transports eggs and fertilized eggs to the uterus from the ovary • Have cilia at the ends to “coax” egg from ovary • Fertilization occurs here • Up to 24 hours after ovulation – sperm can survive for 3 days • Egg enters uterus 6-7 days after ovulation

  22. Organs • Uterus (womb) • pear-shaped • Pathway for sperm deposition into vagina to reach fallopian tubes • Site of implantation for fertilized egg • Growth of fetus during pregnancy • Labor • Source of menstrual flow

  23. Organs • Uterus • Fundus • Body • Cervix

  24. Organs • Cervical mucus • Water, glycoproteins, lipids, enzymes, salts • More hospitable to sperm during ovulation • Helps protect sperm on passage to uterus • Vagina • Fibromuscular canal • Receptacle for penis • Outlet for menstrual flow • Passageway for childbirth

  25. Organs • Vulva - External genitals of female • Mons pubis – adipose tissue, skin, hair • Labia majora – two folds, covered by pubic hair • Labia minora – two folds, underneath labia majora, no hair • Clitoris, glans – erectile tissue and nerves, sexual excitement in females

  26. Female External

  27. Organs • Mammary glands • Breast • Nipple – where milk emerges • Areola – darkened area around nipple • Mammary gland – modified sweat glands

  28. Disease/Medical • Ovarian cysts • Fluid-filled sac in or on ovary • Usually noncancerous, can go away on their own • Uterine prolapse • When uterus is outside the vagina • Occurs with age, disease, traumatic vaginal delivery, difficult bowel movements, coughing • Can be put back with surgery

  29. Disease/Medical • Hysterectomy • Removal of uterus • Episiotomy • Fetus stretches perenial region • Performed to prevent tearing • Straight, tearing is jagged

  30. Oogenesis

  31. Male/Female Homologous Structures

  32. Review • What is the function/structure of: • Uterus • Ovaries • Fallopian tubes • Vagina • Mammary glands • Describe oogenesis.

  33. Objectives • Describe the hormones that are important to the reproductive cycle. • Summarize female reproductive cycle. • Describe various methods of birth control.

  34. Female Reproductive Cycle • Ovarian Cycle – events in the ovaries that occur during and after the maturation of an oocyte • Menstrual Cycle – changes in the endometrium (lining) of the uterus to prepare for the arrival of a fertilized ovum that will develop until birth • Female reproductive cycle includes both of these

  35. Hormones of Cycles • Gonadotropin-releasing hormone (GnRH) • Secreted by hypothalamus • Stimulates release of FSH and LH • Stimulate release of egg from ovaries • Estrogens • Secreted by ovaries • Promote development of sex characteristics • Progesterone • Secreted by ovaries • Prepare and maintain endometrium for implantation • Prepare mammary glands for milk secretion

  36. Hormones of Cycles • Relaxin • Relaxes the uterus by inhibiting contractions • Increases flexibility of pubic symphysis • Helps dilate cervix • Inhibin • Secreted after ovulation • Inhibits secretion of FSH and LH

  37. Hormonal Changes Tortora & Grabowski 9/e 2000 JWS

  38. Summary • Cycle is counted from 1st day of last period • Menstruation lasts 4-5 days • Proliferative phase (13 days) • Endometrium fills will tissue and blood • Ovulation occurs around day 14 • Secretory phase (10 days) • If egg is fertilized, tissue stays to care for fetus • If egg is not, menstrual phase begins again

  39. Birth Control • Oral contraceptives (the pill) – inhibits FSH and LH from being released, ovulation doesn’t occur, no egg for fertilization – close to 100% effective • “morning-after-pill” – causes shedding of lining (induces period) to prevent implantation • IUD – prevent implantation in uterus by changing lining • Spermicides – kill sperm, more effective with use of condom or diaphragm

  40. Birth Control • Barrier methods – prevent sperm from getting into uterus (condoms, diaphragm); also helps protect against STD’s • Periodic Abstinence – couple learns “cycle” and abstains during that time

  41. Review • Describe various methods of birth control. • Describe the hormones that are important to the reproductive cycle. • Summarize the reproductive cycle.

More Related