1. Biology, 9th ed, Sylvia Mader
Chapter 43
Chapter 43
Reproductive Systems
Reproductive Systems

2. Outline
Male Reproductive System
Female Reproductive System
Control of Reproduction

3. Male Reproductive System
Male gonads
Paired testes suspended in scrotum
Sperm
Produced by testes
Mature within epididymides
Propelled into vas deferentia by muscular contractions

4. Male Reproductive System
Penis is cylindrical organ hanging in front of scrotum
Three cylindrical columns of spongy, erectile tissue
Blood flow stiffens penis and increases its size
Seminal fluid contains
Sperm
Secretions from
Seminal vesicles
Prostate gland, and
Bulbourethral gland

5. The Male Reproductive System

6. Penis Anatomy

7. Emission - First phase of ejaculation
Nerve impulses sent to epididymides and vasa deferentia
Sperm enter ejaculatory duct
Secretions released
Expulsion
Rhythmical muscle contractions
Expel semen in spurts from opening of urethra
Contractions are part of male orgasm

8. Testes contain one to three coiled seminiferous tubules
Testes and Sperm
Testes contain one to three coiled seminiferous tubules
Mature sperm have three distinct pieces
Head
Acrosome
Mid-piece
Tail
Normal human ejaculate contains several hundred million sperm

9. Testis and Sperm

10. Hormonal Regulation in Males
Hypothalamus has ultimate control of testicular sexual function
Gonadotropic Hormones
Follicle Stimulating Hormone
Promotes spermatogenesis
Occurs in seminiferous tubules
Lutenizing Hormone
Control production of testosterone
Testosterone produced by interstitial cells of testis

11. Hormonal Control of Testes

12. Female Reproductive System
Ovulation
An oocyte (egg) bursts from an ovary into coelom
Swept into oviduct by currents in coelomic fluid
Fertilization normally occurs in oviduct
Ciliary movement moves zygote to uterus
Embryo embeds in uterine lining (endometrium)

13. Female Reproductive System

14. Female Reproductive System
External genital organs are collectively known as the vulva
Mons pubis and labia minora and labia majora are on either side of urethral and vaginal openings
Clitoris has a shaft of erectile tissue and is capped by pea-shaped glans

15. Ovarian Cycle

16. Ovaries release ova and produce estrogen and progesterone
Ovarian Cycle
Ovulation
Release of secondary oocyte from a vesicular follicle
Follicle develops in corpus luteum
Degenerates if no pregnancy

17. Ovarian Cycle Follicular Phase Luteal Phase
FSH promotes development of follicle
Follicle then secretes estrogens
Luteal Phase
LH promotes development of corpus luteum
Corpus luteum then secretes progesterone

18. Hormonal Control of Ovaries

19. Uterine Cycle
Sex hormones produced in ovarian cycle affect endometrium
Days 1-5:
Endometrium disintegrates
Menses pass out vagina during menstruation
Days 6-13:
Endometrium thickens
Ovulation usually occurs on 14th day
Days 15-28:
Endometrium doubles in thickness

20. Female Hormone Levels During the Ovarian and Uterine Cycles

21. Originates from both maternal and embryonic tissues Produces
Placenta
Originates from both maternal and embryonic tissues
Produces
Human chorionic gonadotropin (HCG)
Maintains the corpus luteum until the placenta begins its own hormone production

22. Biology, 9th ed, Sylvia Mader
Female Breast
Chapter 43
Reproductive Systems
Each breast contains between 15 and 24 lobules, each with its own mammary duct
Lactation caused by prolactin
Colostrum produced until milk production begins
Milk production begins a few days after delivery of a baby
2.C.1: Lactation in mammals

23. Anatomy of the Breast

24. Control of Reproduction
Biology, 9th ed, Sylvia Mader
Control of Reproduction
Chapter 43
Reproductive Systems
Traditional Birth Control Methods
The most reliable method of birth control is abstinence; it has the advantage of preventing transmission of a sexually transmitted disease.
Male and female condoms are other means to help prevent pregnancy.
Birth Control Pills
These regimens either prevent fertilization or stop a fertilized egg from implanting.
3.D.4: Drugs (Hypertensives, Anesthetics, Antihistamines, and Birth Control)

25. Biology, 9th ed, Sylvia Mader
Infertility
Chapter 43
Reproductive Systems
Common Causes of Infertility
Females - Endometriosis
Males - Low Sperm Count
Assisted Reproductive Technologies
Artificial Insemination by Donor (AID)
In Vitro Fertilization (IVF)
Gamete Intrafallopian Transfer (GIFT)
Intracytoplasmic Sperm Injection (ICSI)

26. Biology, 9th ed, Sylvia Mader
Chapter 43
Ending Slide Chapter 43
Reproductive Systems
Reproductive Systems