1. Chapter 26: Reproductive Systems

2. Copyright © 2007 by Saunders, an imprint of Elsevier Inc.
Lesson 26.1 Objectives
List the structures and functions of the male and female reproductive systems.
Describe the structure and function of the testes.
Describe the structure and function of the male genital ducts.
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3. Lesson 26.1 Objectives (cont’d.)
Describe the accessory glands that add secretions to the semen.
Describe the hormonal control of male reproduction, including the effects of testosterone.
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4. Copyright © 2007 by Saunders, an imprint of Elsevier Inc.
Reproductive Systems
Functions of the reproductive systems:
Produce, nurture, and transport ova and sperm
Secrete hormones
Reproduction is sexual- meaning that both a female and male partner are required for reproduction
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5. Reproductive Systems (cont’d.)
Reproductive organs:
Primary reproductive organs: gonads
Female gonads: ovaries
Male gonads: testes
The functions of the gonads are to secrete hormones and produce gametes (eggs and sperms)
Secondary reproductive organs: all other organs, ducts, and glands in the reproductive system
Function is to nourish and transport the eggs and sperm
Female secondary structures provide a safe, nurturing environment for the fertilized egg

6. Male Reproductive System
Roles of the male reproductive system:
Produce, nourish, and transport sperm
Deposit sperm within the female reproductive tract
Secrete hormones
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7. Male Reproductive System (cont’d.)
Testes: testicles; male gonads
2 functions- produce sperm and secrete testosterone
Located outside of the abdominal cavity in the scrotum
Testosterone: male hormone
Lobules: smaller units of the testis
Approx. 250 lobules in each testis
Contains interstitial cells (produce androgens)and seminiferous tubules (produce sperm)
Androgens: male hormones, including testosterone

8. Pathway of sperm

9. Male Reproductive System (cont’d.)
Spermatogenesis: formation of sperm
Most sperm live only a few hours; some may survive up to 3 days
Spermatogonia: undifferentiated spermatogenic cells
Meiosis: special type of cell division; reduces the number of chromosomes from 46 to 23 in the primary spermatocytes
Each sperm has only 23 chromosomes same as each egg; when they unite, they form a zygote with 46 chromosomes
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11. Male Reproductive System (cont’d.)
Genital ducts:
Epididymis: first part of the duct system; located along the top and posterior side of the testis (about 20 feet long); sperm mature and become motile
Vas deferens: continuous with the epididymis; curves over the urinary bladder and joins the duct of the seminal vesicle to form the ejaculatory duct
Ejaculatory ducts: pass through the prostate gland and join with the urethra
Urethra: extends from the base of the urinary bladder to the tip of the penis; part of the reproductive and urinary system; never passes urine and semen at the same time

12. Male Reproductive System (cont’d.)
The pathway for semen.
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13. Male Reproductive System (cont’d.)
Accessory glands: (as the sperm travel through the ducts various secretions are added)
Seminal vesicles: located at the base of the bladder; secrete a thick, yellowish material (rich in fructose, vitamin C and prostaglandins which nourish and activate the sperm)
Prostate gland: encircles the upper urethra just below the bladder; secretes a milky, alkaline substance (increases sperm motility and helps neutralize the acidic secretions of the vagina)
Bulbourethral glands (Cowper’s glands): tiny glands that secrete thick mucus into the urethra; serves as a lubricant

14. Male Reproductive System (cont’d.)
Semen: mixture of sperm and the secretions of the accessory glands
The amount of semen secreted is only about 2 to 6ml, but contains 50 to 100 million sperm
External genitals: scrotum and penis
Scrotum: sac that hangs between the legs and contains the testes; helps to regulate temperature
Penis: carries urine through the urethra to the outside of the body and deposits sperm in the female reproductive tract; contains erectile tissue and is considered the organ of copulation

15. Male Reproductive System (cont’d.)
Glans penis: the enlarged tip of the penis
covered with loose fold of skin called the prepuce, or foreskin
Erection: accumulation of blood in the erectile tissue causing the penis to enlarge and become rigid
Orgasm: pleasurable sensations that occur at the height of sexual stimulation
Accompanied by emission and ejaculation
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16. Male Reproductive System (cont’d.)
Emission: movement of sperm and glandular secretions from the testes and genital ducts into the proximal urethra
Up: Erection—parasympathetic nervous system
Out: Emission—sympathetic nervous system
Ejaculation: expulsion of semen from the urethra to the outside
Up: Erect—parasympathetic nervous system
Down: Flaccid—sympathetic nervous system
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17. Copyright © 2007 by Saunders, an imprint of Elsevier Inc.
Lesson 26.2 Objectives
Describe the structure and function of the ovaries.
Describe the structure and function of the female genital tract.
Explain the hormonal control of the female reproductive cycle.
Copyright © 2007 by Saunders, an imprint of Elsevier Inc.
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18. Female Reproductive System
Three roles:
Produce eggs
Secrete hormones
Nurture and protect a developing baby during the nine months of pregnancy
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21. Female Reproductive System (cont’d.)
Ovaries: female gonads
Found on either side of the uterus; close to the fallopian tubes, held in place by ovarian and broad ligaments
Ovarian follicles: tiny saclike structures within the ovary (born with approx. 2 million)
Oocyte: immature egg
Follicular cells: cells surrounding the oocyte in the ovarian follicle
Graafian follicle: mature ovarian follicle
Ovum: mature egg

23. Female Reproductive System (cont’d.)
Ovulation: ejection phase of a mature egg
Occurs approximately once per month
Fimbriae: fingerlike projections at the end of the fallopian tubes; perform swishing motion to sweep the ovum into the fallopian tubes
Corpus luteum: glandular structure developed by follicular cells that remain in the ovary after ovulation
Corpus albicans: deteriorated corpus luteum
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24. Female Reproductive System (cont’d.)
Effects of estrogen:
Promotes the maturation of the eggs
Helps develop the female secondary sex characteristics
Enlargement and development of the organs of the female reproductive system
Enlargement and development of the breasts
Deposition of fat beneath the skin
Widening of the pelvis
Onset of menstruation
Closure of the epiphyseal discs in long bones
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25. Female Reproductive System (cont’d.)
Effects of progesterone:
Works with estrogen in establishing the menstrual cycle
Helps maintain pregnancy
Prepares the breasts for milk production after pregnancy
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26. Female Reproductive System (cont’d.)
Fallopian tubes
Extend from either side of the uterus to the ovaries (also called the uterine tubes or oviducts)
Infundibulum: funnel-shaped end nearest the ovary
Has finger-like projections called fimbrae that hang over the ovary and sweep the egg from the surface of the ovary into the fallopian tube
Peristalsis moves the egg along the fallopian tube toward the uterus; the fallopian tube is the usual site of fertilization of the egg by the sperm
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27. Female Reproductive System (cont’d.)
Uterus:
Shaped like an upside-down pear; located between the urinary bladder and the rectum
Held in place by broad ligaments
Three layers include epimetrium (perimetrium), myometrium and endometrium
Parts of the uterus
Fundus: upper dome-shaped region above the entrance to the fallopian tubes
Body: central region
Cervix: lower narrow region; opens into the vagina

28. Female Reproductive System (cont’d.)
Vagina
Extends from the cervix to the vaginal opening in the perineum
Hymen: thin membrane covering the vaginal opening
Fornices: pockets that form in the vagina around the cervix
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30. Female Reproductive System (cont’d.)
Vulva: external genitals
Labia majora: folds of hair-covered skin that lie external to the labia minora
Labia minora: inner folds of skin separated by a cleft containing the urethral and vaginal openings
Clitoris: contains sensory receptors that allow the female to experience sexual sensations; contains erectile tissue- similar to the penis
Vestibular glands: secrete a a mucus-containing substance; lie on either side of the vaginal opening
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31. Methods of Birth Control
Birth control: voluntary regulation of reproduction
Barrier method: prevents the sperm from entering the female
Hormonal contraceptives (e.g., the Pill): prevent ovulation by maintaining hormone levels
Surgical methods: vasectomy and tubal ligation
Intrauterine device: prevents implantation
Behavioral methods: abstinence, the rhythm method, and coitus interruptus
Emergency contraception: prevents ovulation and inhibits implantation or causes endometrium to slough
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32. Methods of Birth Control (cont’d.)
Copyright © 2007 by Saunders, an imprint of Elsevier Inc.
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33. Two methods of tubal ligation

34. Types of Birth Control