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Reproduction Ch. 28.

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Presentation on theme: "Reproduction Ch. 28."— 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 Epididymis
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 Ejaculatory ducts Urethra
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 Prostate
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 mL of fluid with million sperm/mL 20 million/mL or lower is considered infertile Slightly basic ( ); 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 Vasectomy
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 Uterine tubes (fallopian) or oviduct
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 Vagina
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 Uterine prolapse
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 Episiotomy Removal of uterus
Fetus stretches perenial region Performed to prevent tearing Straight, tearing is jagged

30 Oogenesis

31 Male/Female Homologous Structures
Ovaries Testes Ovum Sperm cell Labia majora Scrotum Labia minora Spongy urethra Clitoris Glans penis

32 Review What is the function/structure of: Describe oogenesis. 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) Estrogens
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 Prepare and maintain endometrium for implantation Prepare mammary glands for milk secretion

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


38 Hormonal Changes Tortora & Grabowski 9/e 2000 JWS

39 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

40 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

41 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

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

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